Search Results for: pilling

Lisa A. Pierson, DVM

Think about the last time you swallowed a pill or a capsule.  You most likely took it with several swallows of something liquid to help move the pill along its journey through the esophagus and into the stomach.  Most people would never dream of ‘dry swallowing’ pills, having felt that awful sensation of a pill not ‘going down’ very smoothly so why are we subjecting our animals to this illogical procedure?  When humans feel that a pill is stuck, we usually react by drinking more water.  It would be nice if cats and dogs reacted this way, but they don’t.

Note:  When I use the word “pill,” I am also referring to capsules which can cause even more problems than pills, as shown in the study below.

Here is a quote from a colleague of mine:

Last year, I was prescribed clindamycin (Antirobe) for a dental infection and was instructed to take each capsule with a full glass of water.  One night, being lazy, I took the capsule with just a gulp of water.  What ensued was the worst case of heartburn/esophagitis I have ever had.  At first, the pain was so intense I thought I was having a heart attack.  This cured me of ever pilling a cat without a water or food chaser.“

Given how humans take their medications and vitamins (with a liquid in some form),  we need to stop asking our cats and dogs to do something we would never do.

The lining of the esophagus is very delicate and it is not designed to have irritating medications in contact with it for more than the short amount of time it should take for the pill to pass from the mouth to the stomach when swallowed with an adequate amount of liquid or food.

When a pill is in contact with this tissue for a prolonged period of time, a painful irritation or ulcer has the potential to develop.  Some medications are worse than others.  For instance, doxycycline is a well-known antibiotic that is extremely irritating.  (More on that below from a human who experienced very painful erosive esophagitis from taking this medication without enough water.)

For this article, a “dry swallow” refers to the administration of a pill or capsule to a cat or dog without the patient immediately (within 1-2 minutes):

1) consuming some food or liquid (milk, tuna water, meat broth, etc.) voluntarily – or

2) having 4-5 milliliters (cc) of water, milk, tuna water, or meat broth given orally via a syringe.

Offering food, tuna juice, milk, meat baby food, or a meat broth for them to lap up on their own results in less stress for the patient but many animals are not keen on eating or drinking right after a human as ‘pilled’ them.

As noted on my Feeding Your Cat: Know the Basics of Feline Nutrition article, as well as in many other articles on this website, I am strongly opposed to the feeding of dry food to cats. That said, if you are dealing with a dry food-addicted cat, feeding a bit of dry food or treats (such as Temptations treats) after administering the pill will also help ‘chase’ it into the stomach, but canned food – with its much higher water content – is a healthier choice.

Hopefully, after looking through my website, you will be convinced to get your cat on a better diet than dry food.  See my Tips for Transitioning Dry Food Addicts to Canned Food.

Tip:  You can make your own tuna water by mixing a can of tuna with ~3 cups of water.  Mash it up and let it sit for ~10-15 minutes. Then pour the water off into ice cube trays to prolong the freshness then store the cubes in a ziplock bag.  It is fine if some tuna meat is included into the ice cube unless you will be syringing this flavored water. If you are using a syringe to administer the water – versus letting them lap it up – then I would strain the water to remove any chunks of tuna that would clog the syringe.

Rather than ‘pilling’ a cat or dog, by far, my absolute favorite way to administer pills or capsules is with the use of Pill Pockets.

If the cat refuses to eat Pill Pockets, even when rolled in FortiFlora, paremsan cheese, or crushed Temptations treats, an alternative to pilling is to have the medication made up into a flavored liquid compound for ease of administration.  That said, some people state that their cat is not good about swallowing liquids and these people prefer to use pills.

Back to Pill Pockets….

Do not use a whole Pill Pocket at a time.  They are too big and most cats will bite down on them. Instead, use just enough of the ‘dough’ to wrap around the pill – being careful not to get any of the pill powder on the outside of the Pill Pocket if you have broken up the pill into pieces.

A cat is going to be much less apt to bite down on ~1/4 of a Pill Pocket than he will be if offered a whole Pill Pocket.  I break the Pill Pocket into 4 – 5 pieces.

See this video showing how I broke a Pill Pocket into 5 pieces and then rolled them into little balls.  The first two pieces have 1/2 of Andy’s pill in each of them. The other 3 pieces are also fed as a treat and also to help push the pill down into the stomach.

Note how I quickly throw down each piece.  This is to get Andy to swallow the one that is in his mouth which he does because he is anxious to gobble up the next piece.

Again, if your cat will not eat Pill Pockets, try rolling them in crushed up treats such as Temptations treats or FortiFlora.  FortiFlora is a probiotic (beneficial bacteria) that comes in a box with 30 small packets but I am not suggesting it for its probiotic purpose. The reason why I love this product is because the probiotics are contained in a very enticing animal digest powder. This is what is sprayed on dry kibble to make it so palatable.

I think that my cats would eat cardboard if I sprinkled FortiFlora on it!  I always keep this product in my home as a flavor enhancer to be used if my cats don’t want to eat for any reason or if I am trying to get them to eat a new food.  Think of it like salt and pepper for your own food.  You can use as little as 1/10 of a package or even less.  Also, don’t worry if the product is outdated because we don’t care if the probiotic bacteria have died since we are only using it for a flavor enhancer.

FortiFlora is my favorite trick listed on my Tips for Transitioning Dry Food Addicts to Canned Food paper but Temptations treats may work just as well and will be easier to find at your local pet store.

Some cats also love parmesan cheese so you can also try rolling the Pill Pocket in parmesan cheese.

When administering pills or capsules, some people use butter or oil to coat the pill/capsule.  This may make swallowing the pill easier but it is not going to ensure rapid passage into the stomach.  Therefore, it is still very important to follow a butter-coated pill with a liquid or food chaser to ensure that the pills or capsules move immediately into the stomach.

If a cat absolutely will not allow water to be syringed after pilling, or he will not eat or drink afterward, then you can put some butter or a product like Nutrical on his paw.  The licking of the butter/Nutrical from the paw (or even the nose) has been shown to hasten the travel of the pill into the stomach but it is not as effective as having the cat eat after pilling or ‘chasing’ the pill with 4-5 cc of water or a flavored liquid.

The best size of syringe to use for a cat – whether you are syringing the medicine or a water chaser – is a 1 ml (cc) syringe.  The larger syringes do not fit comfortably inside of a cat’s mouth.  Also, you do not want to administer any more than 3/4 – 1 cc at a time.  If liquid medications, such as some of the commonly used antibiotics, are dispensed with an eyedropper, ask your veterinarian for a 1 ml syringe.  Not only is this a more accurate way to measure the dose, but your cat will be more agreeable to this small syringe entering the side of his mouth rather than the larger eyedropper that you have to squeeze a couple of times to eject the medication.

If you have chosen the option to pill your cat, I would suggest that before you get ready to administer the pill, have a bowl of water (or tuna juice or broth or milk) readily available.  See if your cat is interested in drinking it.  If not, you will then have to use your syringe.  To administer a liquid using a syringe, it is best to approach the cat from the side, not from the front.  Cats tend to get worried when approached head on.  Slip the syringe into the side of the mouth at about a 45-degree angle being careful not to insert the syringe too far down the back of the throat.  You don’t want the cat to panic, nor have him aspirate the liquid.

Do not hold your pet’s head up! 

This is something that I commonly see people do.  Try it yourself.  Lift your chin up and note that it is impossible to swallow.  You can hold his head level or his mouth slightly down, but never raise his head upward.

I fully understand that some of the readers will be saying “oh sure…I can barely get the pill down my cat and now I am supposed to follow up with the syringing of some liquid?!!?”

I realize that none of this will be easy with some cats, but my goal is to get people to start thinking about this issue and not take the dry pilling of an animal lightly.  For those hard-to-pill cats, please see below for other alternatives such as compounded, flavored liquid medications and transdermal preparations.

Another option is to see if the cat or dog will consume the pill if it is hidden in canned food.  This is obviously the least stressful for all concerned and it works much better with dogs when compare to cats.  Cats are notoriously picky eaters and are suspicious of anything out of the ordinary in their food and it would be very rare to have a cat eat a whole pill when mixed into cat food.

Some drugs such as Clavamox tablets and Baytril TasteTabs are formulated to be fairly palatable and can be crushed and put in canned food and this is a great way to go….if the cat will eat it.

I have had better luck with cats eating crushed Clavamox tablets (tasteless) in food than I have with the Baytril TasteTabs.  I have treated many feral (wild) cats with clavamox tablets crushed and mixed into food.

Please note the following case study where another antibiotic, clindamycin (Antirobe), resulted in severe injury – and some deaths – to the patients when they were dry pilled.

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Suspected clindamycin-associated oesophageal injury in cats: five cases

Journal of Feline Medicine & Surgery, Volume 8, Issue 6, December 2006, Pages 412-419
Julia A. Beatty BSc(hons), BVetMed, PhD, FACVSc (Feline Medicine), MRCVS, Nigel Swift BVetMed, Dip ACVIM (Small Animal Internal Medicine), MRCVS, Darren J. Foster BSc, BVMS, PhD, FACVSc (Feline Medicine) and Vanessa R.D. Barrs BVSc(hons), MVetClinStud, FACVSc (Feline Medicine)

Accepted 24 April 2006.  Available online 18 July 2006.

Summary:

The clinical findings, treatment and outcome of suspected clindamycin-associated oesophageal injury in five cats are reported. All cats were treated with one 75 mg clindamycin capsule twice daily (dose range 12–19 mg/kg). Capsules were administered without food or a water bolus. Dysphagia, regurgitation, choking or gagging were seen 3–9 days after starting clindamycin. On oesophagoscopy, three cats had oesophagitis, one of which progressed to stricture formation. Two cats had an oesophageal stricture at first presentation. This is the first report of suspected clindamycin-associated oesophageal injury in cats. It serves to further alert practitioners to the potential for drug-induced oesophageal disorders (DIOD) in cats treated with oral medications and to urge prevention by promoting a change in dosing practices.”
End abstract.

Personally, I have dealt with 3 cats that have died post-pilling with clindamycin (Antirobe) tablets.

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Please note this excerpt from the study quoted below:

After 5 minutes 84% of capsules and 64% of tablets are still sitting in the esophagus.”

This is referring to pills and capsules that were dry swallowed.

It really is amazing that cats and dogs are as good as they are about pilling but one has to wonder about the pets that panic and/or gag when their owners try to pill them.  I know that I would not be very happy about being asked to dry swallow a pill.

A Very Interesting Study

The following is a summary of a very interesting article that appeared in a veterinary journal entitled Evaluation of the Passage of Tablets and Capsules Through the Esophagus of the Cat. It is from a paper presented at the 2001 American College of Veterinary Internal Medicine Forum. (They do note at the end of the paper that the principles outlined also make good sense for dogs.)  This paper was submitted to one of the lesser-read journals so a lot of veterinarians may not have seen it.  This is extremely unfortunate for all cats and dogs.

Purpose of the study:
The goal of the study was to determine the length of time that it took for pills or capsules to enter the stomach after 1) dry pilling and 2) pilling and then giving a 6 cc water chaser immediately following the administration of the pill or capsule – referred to as a “wet swallow.”

Study design:
30 cats were used. Fluoroscopy was used to evaluate the pill/capsule passage at 30, 60, 90, 120, 180, 300 seconds.

Study results:
For the dry swallows:
No pills were in the stomach at 30 and 60 seconds.  Only 6% of the pills were in the stomach at 90 seconds. Only 13% of the pills were in the stomach at 120 seconds. And at 5 minutes only 36% of the pills were in the stomach.

For the wet swallows: (i.e., the pill was followed by 6 cc of water)
At 30 seconds, 90% of the pills were in the stomach. All pills were in the stomach by 120 seconds.

The statistics were even worse for capsules when dry swallowed.  By 5 minutes, only 16% of the capsules had made it to the stomach. 100% of capsules followed by water chasers, were in the stomach by 60 seconds – faster than for pills probably due to the smoother surface of a capsule versus a pill.

Commentary:

This is an interesting study that has considerable practical impact.  Although veterinarians have a huge arsenal of mediations and treatments available to us, we still have a very poor understanding of some of the most basic aspects of everyday practice. We routinely prescribe oral medications in the form of tablets or capsules to cats.

It has been our assumption that when it was possible for the owner to actually give the pills or capsule to the cat, it would make it into the stomach reasonably rapidly. It turns out that this is inaccurate. After 5 minutes 84% of capsules and 64% of tablets are still sitting in the esophagus. Similar results were published in another study by JP Graham (American Journal of Veterinary Research 2000).”

Practical outcome:
The main concern with this information is that if tablets and capsules sit in the esophagus for a prolonged period of time, this can cause damage to the tissues in this area. This damage can lead to esophagitis, which can lead to nausea, vomiting and megaesophagus. At times, the esophagus can also respond by developing an ulcer or stricture. The latter is a very serious complication requiring aggressive therapy, preferably with balloon dilatation.

In addition, we probably have all had that uncomfortable feeling when a tablet we have taken has gotten stuck on the way down. This could be the cause of vomiting in some cats that are medicated. It is quite frustrating to win the battle to get the pill or capsule down a cat and then have it vomited up several minutes later.

Both this abstract as well as the study published by Graham et al., clearly point to the need to administer either water or food after a cat has been pilled with a tablet or a capsule. This will hasten the movement into the stomach and cut down on the chances of the tablet or capsule remaining in the esophagus for a prolonged period of time. Although comparable studies have not been done in dogs, this advice is sound in dogs, as well.

The following is an anecdotal report from a person who ended up with a very painful case of an ulcerated esophagus after a capsule became lodged in her esophagus:

I know the pain of an ulcerated esophagus personally and it is a living hell.  I was on doxycycline capsules (due to a cat bite) last year and one got stuck in my esophagus.  I did not think it was a big deal and went to bed figuring it would eventually work it’s way down. Several days later I had suffered so much that I took myself to the ER.  I had to drink this horrible tasting cocktail with liquid lidocaine to get relief. It worked, temporarily, but I had to drink a tsp of the lidocaine 3x a day just to be able to swallow for about 30 minutes each time.  Forget eating.  I lost 10+ lbs in less than 2 weeks. I couldn’t eat at all and could not swallow without the lidocaine.  I laid in the bed with a cup to spit in because it was too painful to swallow.  It was a great diet, but not one I’d recommend. Please take every precaution you can to make sure this does not happen to your pet.”

Compounded Flavored Liquid Medications

As an alternative to using pills and capsules to administer medications, certain pharmacies can compound the medications into flavored liquids.  Please be aware that compounded medications may be more expensive than medications dispensed by your veterinarian, but the use of these liquid medications can alleviate a great deal of stress for both the pet and the human.

I am very involved in rescue work and often deal with extremely frightened and painful animals whose trust I am trying to gain.  Pilling a sick cat/kitten who is feral or traumatized/frightened/painful, or has severe upper respiratory disease and can hardly breathe as it is, does not exactly make for a fast friendship and development of trust.

When an animal is ill or injured, the last thing we want to do is add more stress to the situation.   I adopted a 9 year old cat out to a really nice woman many years ago. Toward the end of Caliban’s life, the lady called me in tears because Caliban was now in congestive heart failure and she was having a hard time pilling him and was going to put him to sleep since he could no longer receive his necessary medications. She felt so guilty for failing Caliban by not giving him the medications that he desperately needed but was also feeling guilty for stressing the heck out of him in his final days with the pilling. This stress was alleviated by using compounded, flavored liquid medications.

The most common flavor used for cats is ‘triple fish’ and if dealing with a very bitter medication, this flavor is the best one to use.  Another flavor that is used is chicken and some cats do better with this milder flavor than the very strong triple fish.

Please note that some drugs are so bitter that even compounding will not hide the awful taste.  An example of this type of drug is amitriptyline which is often used for anxiety and inappropriate elimination (not using a litter box) problems.  Fortunately, this medication is formulated into a small, coated pill but a food or liquid chaser still needs to be administered if the cat is pilled.

Or, much better would be to use Pill Pockets.

4/26/10 update:  In cases where I have deemed medications necessary, I have had good luck with Prozac for inappropriate elimination problems and it is easier to give than amitriptyline.  I have one patient that was scheduled for euthanasia for constantly urinating on the owner’s bed.  I put the patient on a small dose of Prozac that is fed to her every night in a Pill Pocket.  The owner splits the Pill Pocket into three pieces and only one piece has the tiny pill piece in it but the cat gets all three treats each night.  No stress to either the owner of the patient….and the cat has not (knock on wood….) urinated on the bed for the past 8 months.

2/24/11 update:  The patient discussed above decided that she did not want to eat Pill Pockets anymore but she is now readily eating them if they are rolled in FortiFlora first.

Since we all know that every cat is different, I will mention again that some people state that they have much better luck pilling their cats than trying to get liquids into them.  Some cats throw a fit if given liquid medications.  The problem with these cats, however, is that if you do pill them successfully, they are not apt to take the water chaser very well.  This presents a bit of a problem and the hope is that they will eat some canned food or drink some tuna juice or meat broth after being pilled.

Another favorable aspect of using a compounding pharmacy is that you can pick the drug concentration so that the necessary dosage volume is not over 1cc.  I try to have the medication mixed in a concentration that enables me to give 3/4 of a cc or less.  This is an easy volume to administer to a cat.

Occasionally you may run across a drug that can’t be compounded but I have yet to run into this situation.

Transdermal Medications

Transdermal preparations are medications that are formulated into a gel or ointment that can be applied to the inner ear of the cat.  That said, the only frequently used medication that has shown to be adequately absorbed by this route is methimazole (Tapazole) for hyperthyroidism.

Studies here and here have shown that the use of transdermal methimazole is an effective way to administer this drug and results in fewer gastrointestinal upsets.

Unfortunately, many veterinarians are under the mistaken impression that other medications like steroids, antibiotics, and behavior-altering drugs are adequately absorbed through the skin when they are not.

Conclusion 

The goal of this article is to prevent the silent suffering that our pets often go through when medications are administered without appropriate precautions.  I have outlined several options above:

1) FIRST CHOICE: Try Pill Pockets.  If the patient will not eat Pill Pockets, try rolling them in parmesan cheese, FortiFlora, or crushed Temptations or Pounce Treats.

2) Use compounded, flavored liquid medications.

3) Administer the pill or capsule and follow up with the feeding of their regular food, baby food, tuna juice, a meat broth, or milk.  Dry food or dry treats can also be used but a higher moisture ‘chaser’ is preferred.

4) Administer the pill or capsule and follow up immediately with a chaser of a 4-5 cc of a liquid using a syringe.

5) Use transdermal preparations.  (Tapazol only)

6) Or…be lucky enough to have your cat eat the medication in canned food.

Please pass this information on to anyone whose pets may benefit from the information.  It is my hope that the information will help to save some of our non-speaking friends from a painful esophagitis and their caretakers from the stress of pilling some hard-to-pill cats.

Updated November, 2016
Lisa A. Pierson, DVM

Lisa A. Pierson, DVM

Hyperthyroidism is a very common endocrine disorder of older (usually >10 years of age) cats.  In fact, it is said to be the most common endocrine disorder in cats but judging by the large volume of emails I receive asking for help with feline diabetes management, I would say that it is a toss-up as to which disease is more common.

The catalyst for the writing of this webpage is the recent introduction to the veterinarian-prescribed diet market of Hill’s y/d which is an iodine-deficient diet targeted at feline hyperthyroid patients. 

Please note that Hill’s has made false and misleading statements about this diet that will be addressed below.

What is hyperthyroidism?

What are the signs of hyperthyroidism?

What are the causes of hyperthyroidism?

How is hyperthyroidism diagnosed?

What are the treatment choices of hyperthyroidism?

• radioactive iodine (I-131)

• anti-thyroid medication (methimazole, carbimazole)

• Surgery

• Hill’s y/d – an iodine-deficient canned and dry food

• What does it mean to be an obligate carnivore?

• Would I use y/d?

• Is Hill’s being truthful in their marketing claims?

Comments on hyperthyroidism and chronic kidney disease (CKD)

What is hyperthyroidism?

Hyperthyroidism results from an overproduction of thyroid hormones (mainly T4) from a tumor in the thyroid gland.  This tumor, in over 97% of all cases, is a benign (non-cancerous) adenoma.

To repeat, hyperthyroid patients do not have cancer except in very rare (2-3%) cases where a thyroid carcinoma is the cause of the disease.

An elevation in thyroid hormones increases the metabolic rate of the body which puts stress on the heart, kidneys, nervous system, gastrointestinal tract, liver, as well as all other organs of the body.

Think of how hard your car’s engine has to work and how much fuel it uses if you rev up the motor (increase its rpms) by stepping on the gas pedal while in neutral.

This is what is happening inside your hyperthyroid cat’s body.  Every organ system is under the negative influence of an abnormal increase in the body’s metabolism.

In the analogy above, food is your cat’s fuel and it is being used at a faster rate than normal which results in an increased hunger and weight loss.

Hyperthyroidism is eventually fatal if left untreated.

What are the signs of hyperthyroidism?

Since elevated thyroid hormones negatively affect every organ system in the body, the clinical signs are extremely varied but include some or all of the following – with an increased appetite and weight loss being the two most common:

• increased appetite (but sometimes decreased)
• weight loss (fat and muscle) in the face of a good appetite
• increased activity (“acting like a kitten again”)
• increased drinking and urination
• vomiting
• diarrhea
• heart disease – increased heart rate/’pounding’ heartbeat
• increased respiration rate
• hair coat/skin/nail abnormalities
• nighttime yowling/restlessness/confusion/behavior changes
• high blood pressure (hypertension) – Please note that if your cat’s eyes look like big black pools (dilated pupils), this is a sign of possible retinal detachment which can occur secondary to high blood pressure and will result in partial or total blindness.  Not all hyperthyroid cats become hypertensive but is a good idea to have  your veterinarian monitor your cat’s blood pressure.

What are the causes of hyperthyroidism?

I wish we knew the definitive answer to that question.

Possible causes of hyperthyroidism include:

• Iodine levels in cat food – either too low or too high.  Note that this is a very poorly regulated nutrient in cat food with levels varying over a 30-fold range.

• PBDEs – PBDEs are fire retardant chemicals that can be found in high concentrations in some fish and also in house dust.  Since PBDEs are known to affect thyroid function, and cat foods tend to be high in fish, there may be a causal link between hyperthyroidism and fish consumption.  This is one of several reasons why I recommend against feeding fish-based diets to cats.

• Soy in cat food – Soy is a known disruptor of thyroid gland function.  If you have read my Feeding Your Cat:  Know the Basics of Feline Nutrition which outlines what it means to be an obligate carnivore, you will understand that soy has no logical place in cat food.  However, soy will increase the profit margin for pet food companies.  Therefore, it is present in many cat foods – especially those made by Purina.

According to one study, soy was identified in 60% of all tested cat foods at a level high enough to interfere with thyroid function.

• BPA (bisphenol A) – BPA is a known endocrine disrupter that may play a role in the cause of hyperthyroidism.  BPA is found in the coating of the inside of some cans of pet food.  Generally speaking, the smaller (3 ounces and 5.5 ounces) cans will be less apt to contain BPA than the larger (12-13 ounce) cans.

How is hyperthyroidism diagnosed?

Your veterinarian will perform a thorough physical exam including palpating (feeling) both lobes of the thyroid gland which sit in the throat area near the Adam’s Apple.  A normal thyroid gland should not be large enough to feel whereas an adenomatous thyroid gland will usually be large enough to palpate.

Next, a full blood panel, cbc (complete blood cell count), and urinalysis will be performed to look for any disease process(es) that could explain any of the clinical signs that your cat is exhibiting.

It is important that the blood panel include a total T4 level since this is the most important value to look at when assessing thyroid gland health.  The panel that your vet chooses may also include a free T4 which is also useful in diagnosing some hyperthyroid patients but is not as clearly interpreted as total T4.  Free T4 can be falsely elevated for various reasons.

The panel that I choose to use for my patients includes both total T4 and free T4 but panels vary from lab to lab.

Thyroid scintigraphy (thyroid scan) is considered the ‘gold standard’ for diagnosing mild hyperthyroidism but it is not readily available to most people.  However, as noted below, the best treatment for hyperthyroidism is radioactive iodine and, if available, you should choose a facility that performs thyroid scintigraphy to characterize the size, shape, and location of the abnormal tissue in order to gain more knowledge of the disease severity and to also aid in selecting the proper dosage of I-131.

What are the treatment options for hyperthyroidism?

In the sections below, you will see links to Insights into Veterinary Endocrinologywritten by Dr. Mark Peterson, DVM, DACVIM.  Dr. Peterson is a world renowned expert in feline hyperthyroidism and was the first veterinarian to recognize this condition in the early 1970s.  He has treated over 10,000 hyperthyroid cats in the past 30 + years and has lectured countless times to veterinarians from all over the world regarding topics in endocrinology.

Dr. Peterson and I have collaborated recently regarding the new Hill’s diet, y/d, and on other general nutrition issues.  In combining our individual strengths (Dr. Peterson’s background in endocrinology and mine in nutrition), Dr. Peterson has written several very informative blog entries.

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There are 4 treatment options for hyperthyroidism:

• radioactive iodine (I-131) – the ‘gold standard‘
• anti-thyroid medication (e.g. methimazole)
• surgery
• Hill’s y/d (a diet deficient in iodine – canned and dry)

Note that only radioactive iodine and surgery address the underlying cause of the disease which is a tumor.

Anti-thyroid medication and an iodine-deficient diet do not address the tumor which will continue to grow. 

Therefore, representatives from Hill’s are making a false statement when they claim that y/d “restores thyroid health.”

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Radioactive iodine – 131 (I-131)

Radioactive iodine is the treatment of choice for hyperthyroidism in nearly all cases. This treatment involves an injection of a very small dose of radioactive iodine that is placed just under the skin.  Because the thyroid gland heavily concentrates iodine, the thyroid tumor will be selectively destroyed.

In addition to the thyroid tumor being targeted, any other ectopic (found somewhere other than its normal location) overactive thyroid tissue will also be destroyed. This ectopic tissue is often located in the chest cavity but will show up on a thyroid scan as discussed below.

A small risk (~5%) of hypothyroidism (the opposite of hyperthyroidism) exists if too much normal tissue is also destroyed.  These cats will need to receive thyroxine supplementation temporarily or for life.

On the flip side, a small number of cats (~5%) remain hyperthyroid (and require a second treatment) if not enough of the adenoma is destroyed or if the patient actually has a carcinoma (cancer) instead of a benign adenoma.  In the case of a carcinoma, a much higher dosage of I-131 is needed to effectively treat the disease.

As noted above, a thyroid scan (scintigraphy) helps the clinician determine the size, shape, and location of the abnormal tissue which helps determine the proper dosage of I-131 to ensure the best possible outcome.

Without a scan, the dosage will only be a guess.

Other treatments are discussed below but I can say without hesitation that if any of my own deeply-loved cats ever ended up with hyperthyroidism, this would be the only treatment that I would consider.

Update:  6 months after I wrote the statement above, my Andy had a slight-to-moderate rise in his T4 and was showing clinical signs of hyperthyroidism – weight loss and agitation/restlessness – especially at night.  I took him to our local imaging clinic and had him scanned. Right arrow = normal; Left arrow = thyroid adenoma.

Andy was admitted to the clinic on Sunday.  He was scanned that day and received his I-131 injection on Monday.  He was able to come home on Thursday.

Was he miserable? Yep. Was I stressed and anxious?  You bet.  But now I have my Andy back.  He has gained 1.5 lbs and, at 16 years of age, is doing great.

Many people worry about the hospital stay and the stress that it will cause for the cat.  Yes, it is stressful but the benefits far outweigh the difficult few days and it sure beats having to give a pill (methimazole) twice daily, for the rest of the cat’s life, which is a medication that can have significant side effects and does not address the tumor.  More on this drug below.

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Anti-thyroid medication:

methimazole (Tapazole and Felimazole)

carbimazole is a newer drug that is rarely used and not readily available in the United States.

These drugs are known as ‘anti-thyroid’ medications since they interfere with the thyroid gland’s production of  thyroid hormones.

I will say at the outset of this section on anti-thyroid drugs that I am not a fan of putting any chemical into my own body, or that of my own cats or patients.  For every positive action that a drug exerts on a living being, there are plenty of side effects that are very often overlooked by the doctors prescribing the medications.

There are many cats that do well on these drugs but side effects are not uncommon and include nausea, vomiting, and severe allergic/itchy facial skin reactions and, less frequently, life-threatening liver dysfunction, bone marrow disease, and bleeding problems.

While these drugs effectively lower the thyroid hormones and ameliorate the clinical signs of hyperthyroidism, they do not address the underlying tumor and, therefore, the tumor will continue to grow with the risk that it will become a malignant cancer over time.

As the tumor continues to grow, the dosage will often need to be raised which means that the patient must be monitored with periodic blood tests for life.  The frequency will depend on the patient but as we all know, trips to the veterinarian are expensive and very stressful for the patient.

Other health factors may necessitate lowering the dosage.  Therefore, lab monitoring is very important for these patients.

If methimazole is chosen over I-131, I strongly prefer the transdermal preparation which is a cream that is applied to the ear.  This formulation results in less gastrointestinal (vomiting/diarrhea) side effects when compared to the pill form.

Plus, it is a much more humane and less stressful way to administer the medication.

If the pill form is used, please see my Pilling Cats article and never, ever ‘dry pill’ any medication for any cat or dog. All pills or capsules need to be ‘chased’ with food or at least 4 mls of water via a syringe.

Or, better yet, use Pill Pockets as discussed on the Pilling Cats page.

At first glance, I-131 may appear to be a more expensive treatment but in many cases it turns out to be less expensive when compared to lifelong treatment with methimazole when the cost of the medication and the continued monitoring are considered.

Also, the hassle of twice-daily medication must be considered.

In the end, however, I-131 is closer to being a true cure for this disease than methimazole since it addresses the underlying tumor.

Note that if your cat has been on methimazole and you now want to have him treated with I-131, you may have to withdraw the methimazole for ~1-2 weeks prior to I-131 treatment.

For more information on these drugs, please see Dr. Mark Peterson’s discussion here.

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Surgery

Surgery to remove the thyroid adenoma has fallen out of favor since I-131 became available.  This is true for several reasons:

1)  It is impossible to differentiate normal tissue from tumor tissue.  If both lobes of the gland are involved and removed, this will result in hypothyroidism necessitating lifelong treatment with thyroxine.

2) The parathyroid gland which sits right next to the thyroid gland can be damaged or accidentally removed. The parathyroid gland is critical for calcium balance in the body and if damaged or removed, serious complications, including death, can result.

3)  General anesthesia is necessary which is always a risk but even more so in an older patient with hyperthyroidism considering how many organs are negatively affected by this disease.  Severe heart disease can be present in these patients especially if they have been hyperthyroid for a long time.  Any level of heart disease will increase the risk associated with anesthesia.  For this reason, if surgery is the treatment of choice, it is recommended to stabilize the patient with anti-thyroid medication prior to the surgery.

4) Some hyperthyroid cats have ectopic (not in the normal location) thyroid adenoma or carcinoma tissue located in the chest cavity which the surgeon will not be able to remove.  Plus, the surgeon will not even be aware of its presence unless a thyroid scan was performed.

See here for a more comprehensive chart comparing the pros and cons of each of the 3 treatments discussed above.

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Hill’s y/d

This iodine-deficient diet is the newest addition to the Hill’s ‘alphabet prescription diet’ product line and it is targeted at the feline hyperthyroid patient.  As stated above, representatives of the Hill’s company have made false and misleading statements about this diet that will be addressed below.

y/d is formulated to be deficient in iodine with the simple goal of providing less ‘building material’ for the patient’s thyroid tumor and normal glandular tissue to make thyroid hormones (T3 and T4). Iodine is an important component of these hormones withT3 needing 3 iodine atoms and T4 containing 4 iodine atoms.

The premise of this diet is simply to starve the thyroid gland of iodine but here is where the issue of ‘tunnel vision’ nutrition comes into play.

While starving the thyroid gland of iodine, the entire body – including the thyroid gland itself – is also negatively affected by this deficiency.

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If anybody reading this has not read at least the first part of my Feeding Your Cat: Know the Basics of Feline Nutrition article, I will briefly summarize it here because, before reading my comments about y/d, it is important to understand what constitutes a healthy diet for a cat.

In a nutshell, the cat is an obligate carnivore which means:

• They are designed by nature to get their protein from other animals (meat), not plants (grains/potatoes/other vegetables).

• They lack the enzymes necessary to efficiently process carbohydrates.

• They have a low thirst drive and are designed to get their water with their food.  This means that there is no dry food that is suitable to feed to a cat. 

Their normal prey is ~70% water and in times of drought, they could actually survive on the moisture in their prey.  Canned foods are ~78% water and dry foods are only ~8-10% water.

Several studies have shown that the water intake and urine output of cats fed canned food are double that of dry food-fed cats. This is taking into consideration all sources of water from the food and the water bowl.

Please understand that a cat on a dry food diet will drink much more water from a bowl than a canned food-fed cat but he will not make up the deficit caused by the feeding of a water-depleted diet of dry food.

Considering that water is one of the most important nutrients for every living creature, it is easy to understand why it is much more physiologically sound to feed canned food diets to cats rather than dry food.

See Urinary Tract Health for some graphic pictures of what happens to cats like Opie when fed a water-depleted diet.

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Summary statement regarding y/d:

I would only use this diet if:

• I-131 was not available or the client could not afford the treatment, or
• the patient was not a good candidate for surgery, or
• the patient had shown an intolerance to transdermal methimazole.

In other words, I see y/d as a last resort and certainly not a first-line treatment.

Why?

Because:

• y/d leaves the whole body in a state of iodine deficiency.  This is an excellent example of tunnel vision nutrition – i.e.- only paying attention to the thyroid gland, in this case, and not the rest of the body.  Safety studies have not been conducted to assess the long-term damage to the body when left in an iodine-deficient state.

Most of our knowledge of iodine centers around the thyroid gland but there is strong evidence pointing to iodine as playing an important role in immune health, adrenal function, breast health, and also having antioxidant properties.

• y/d does not address the disease process (tumor) that is causing the hyperthyroidism and the tumor will continue to grow.  Therefore, it does not “restore thyroid health” as claimed by Hill’s.

The longer the tumor is allowed to grow, the higher the chance of it becoming a malignant carcinoma.

• y/d is too low in protein for many cats especially considering the muscle-wasting state that hyperthyroid cats are already in. (See Dr. Peterson’s article here.)

• y/d is too high in carbohydrates. (See Diabetes)  Note that many hyperthyroid cats have sub-clinical diabetes.  Feeding them a high carbohydrate diet could very well tip them over the edge into overt diabetes.

canned y/d: 24% carbohydrate calories

dry y/d: 23% carbohydrate calories

mouse: 1-2% carbohydrate calories

• dry y/d has an extremely unhealthy ingredient list for an obligate carnivore and it is water-depleted. (See Urinary Tract Health.)

Corn Gluten Meal, Animal Fat (preserved with mixed tocopherols and citric acid), Whole Grain Corn, Soybean Mill Run, Dried Egg Product, L-Lysine, Chicken Liver Flavor,…..

Please read the above ingredient list with your cat’s obligate carnivore status in mind.  Also understand that your hyperthyroid cat needs a high amount of high quality protein since the disease is causing his body to ‘eat’ (catabolize) his own muscle mass.

Corn is not a “high quality” protein for a carnivore.

I would never feed a diet like dry y/d to any cat in my care.  It is a more appropriate diet for a horse or a cow to be eating.  Please note that there is no meat in this food.  The only animal-based protein is the dried egg product which is lower on the list than even the fiber source so there is next-to-nothing in the way of animal protein in this diet.

• y/d canned has a better ingredient list than the dry and is at least a properly hydrated diet but note that liver is the first ingredient after water.  Liver is high in vitamin A and a diet of predominantly liver does not represent a species-appropriate balance of nutrients. However, note that liver is cheap and provides a higher profit margin for the company.

Water, Liver, Meat by-products, Chicken, Whole Grain Corn, Rice Flour, Chicken Fat (preserved with mixed tocopherols and citric acid), Chicken Liver Flavor, Powdered Cellulose,…..

See Dr. Peterson’s article: Is Hill’s y/d a Nutritious Diet for Hyperthyroid Cats?

If you choose to feed this diet, please feed the canned version and not the dry.

• The patient cannot be allowed to eat any other food which means no treats of any kind.  He must eat only y/d which can pose a problem in multiple-cat households or if he suddenly stops eating the food.

• This diet cannot be fed to non-hyperthyroid cats.  Hill’s states that it can be fed to normal cats if these cats are also fed some regular food.  However, I would not subject your healthy cat to this diet with the hope that you feed enough food from another source to meet his iodine needs – especially in light of the fact that there are diets on the market that are very low in iodine – too low to furnish enough iodine to make up for the bulk of the diet being iodine-deficient.

In my strong opinion, Hill’s is being very irresponsible when making the recommendation to:  “supplement (y/d) with 1 tablespoon of regular cat food (dry or canned) each day to provide additional iodine”.  Given the wide range of iodine in commercial cat food, this recommendation will not ensure adequate iodine in every healthy cat that may be subjected to y/d as the bulk of their diet.

• There is compelling scientific evidence to show that feeding an iodine-deficient diet can actually make the hyperthyroid patient worse over time.

When there is not enough iodine in the body, thyroid hormones decrease. This signals the pituitary gland to secrete TSH (thyroid stimulating hormone).  TSH’s action on the thyroid gland causes it to grow larger (hypertrophy/goiter).

Thyroid Response to Low Intake of Iodine:

• Deficient dietary iodine intake causes the thyroid gland to make less T4
• Plasma T4 levels drop
• This results in increased TSH release from the pituitary gland
• leading to increased iodide trapping in the thyroid gland to maintain T3 secretion
• resulting in thyroid hypertrophy due to increased TSH release = GOITER

If you are interested in learning more about the biochemistry of iodine deficiency and thyroid disease, see Dr. Peterson’s article:  Does Iodine Deficiency Cause Thyroid Disease in Cats?

Reminder: y/d is an iodine-deficient diet.

Here is an excerpt from Dr. Peterson’s article:

So, based on the trend to lower iodine levels in cat food over the last two decades, could iodine deficiency be contributing to the explosion in hyperthyroid cases that we are seeing today?

In support of that reasoning, a recent case-control study reported that cats consuming commercial foods which were relatively deficient in iodine were more than 4 times as likely to develop hyperthyroidism compared with cats that ate iodine-supplemented foods.”

…and another excerpt from Dr. Peterson’s article under the heading:

 Could y/d make this situation worse?

…..will lowering T4 and T3 secretion in these hyperthyroid cats lead to increases in circulating TSH and continued stimulation of thyroid growth and proliferation in some cats? Will this TSH stimulation cause transformation of benign adenomatous thyroid tissue to carcinoma, as has been documented to occur in some hyperthyroid cats?

The short answer is this: we simply do not know. The long-term safety studies needed to answer this question have not yet been done.

Because Hill’s y/d is not a drug (although it’s certainly being marketed as a replacement for methimazole), the company is not required to do the these safety studies, and it’s fairly clear that they have no intension of paying to have them done.”

Also note this excerpt from an article that appeared in the Journal of Feline Medicine and Surgery (2010) entitled Feline Hyperthyroidism: Potential relationship with iodine supplement requirements of commercial cat foods:

Feline hyperthyroidism resembles toxic nodular goiter (TNG) of humans with discrete foci of benign adenomatous hyperplasia.  The etiology of TNG includes iodine deficiency and consumption of or exposure to goitrogens in food, water, and the environment.”

The article goes on to discuss evidence that the current NRC dietary minimum iodine requirement of 1.4 ppm may be too low and may be contributing to feline hyperthyroidism.

Note that y/d is a very iodine-deficient diet at 0.2 ppm (range 0.1 – 0.3 ppm) and we know that iodine-deficient diets cause goiter.

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Is Hill’s being truthful in their marketing claims?  Are they considering what is best for your hyperthyroid cat?

You be the judge.

• Hill’s states that this diet “restores thyroid health”.  After reading the information above, I hope that you can see that this is a blatantly false statement.

Hyperthyroidism is caused by a benign thyroid gland tumor.  Feeding a diet that is deficient in iodine is not halting the growth of the tumor. 

In addition, it has been common knowledge for many years that diets deficient in iodine cause goiter (thyroid gland enlargement).

The tumor will keep growing unless addressed with I-131 or surgery. This continued growth will only enhance the chances of the benign tumor becoming cancerous.

Therefore, it should be very clear that this diet does not “restore thyroid health.”

• Hill’s is calling this an “iodine-restricted” diet and claiming that it is “not iodine-deficient” which is in direct contradiction to their own study as well as studies of other researchers who have investigated the dietary iodine needs of the cat.

To illustrate why their statement is false:

There are studies showing that the minimum iodine requirement in cat food should be 1.4 ppm. In fact, the current NRC requirement states a minimum of 1.4 ppm.

A Hill’s study using a corn-based diet stated that the minimum iodine requirement was 0.46 ppm.

y/d is 0.2 ppm (range 0.1 – 0.3 ppm)

How can Hill’s perform a study coming up with 0.46 ppm as a minimum requirement and then state that a diet with less than half that amount is “not iodine-deficient”?

Here is what Dr. Mark Peterson has to say about this issue in his blog entry entitled Treating Hyperthyroid Cats with an Iodine Deficient Diet (Hill’s y/d): Does It Really Work?

“Hill’s y/d is clearly an iodine deficient diet, containing levels of approximately 0.2 mg/kg (0.2 ppm) on a dry matter basis, well below the minimum daily requirement for adult cats (0.46 mg/kg or 0.46 ppm) of food. It’s important to note that the study that established this minimum daily requirement for cats was done by investigators funded by Hill’s Pet Nutrition. So, claims that this is just a low iodine diet, but not one deficient in iodine is nonsense, unless one does not believe the results of that study.”

An important issue regarding the Hill’s iodine study is that they fed the test cats a corn-based diet.  No nutrient is an island unto itself.  All nutrients are influenced by other nutrients in the diet.  Therefore, it only makes sense to feed a cat a species-appropriate diet (which corn is not) when trying to figure out the optimal level of any nutrient in the diet.

Since Hill’s is known for manufacturing feline diets with high levels of species-inappropriate ingredients to enhance their profit margin, it was not the least bit surprising to learn that their iodine study involved feeding cats a corn-based diet.

Did this skew the results?  We have no way of knowing but, again, if you are going to conduct any nutrient study, common sense dictates that you at least feed the test subjects a species-appropriate diet which, in this case, would be meat – not corn.

• This statement is appearing in our veterinary journals:

“Managing hyperthyroidism is now as easy as feeding your cat,” says Dru Forrester, DVM, MS, Dipl. ACVIM, director of Scientific & Technical Communication for Hill’s Pet Nutrition.

This irresponsible and misleading marketing is going result in far fewer cats receiving the gold standard treatment of I-131.

It is natural for all of us to want to take the easy (and cheaper) way out and this inherent desire is exactly what the Hill’s marketing team is focusing on as is evident by Dr. Forrester’s statement above.  However, ‘easy’ is not always ‘healthy.’

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Comments on treating hyperthyroid patients that also have CKD (chronic kidney disease):

Since hyperthyroidism and kidney disease are common problems in older cats, it should come as no surprise that many hyperthyroid patients also have concurrent kidney disease.  It is estimated that 30-35% of all hyperthyroid cats also have some level of kidney disease.

However, the increased metabolic rate of the hyperthyroid patient can make the kidneys looking better ‘on paper.’  This is because  an elevated metabolic rate causes an increase in blood flow/increase in pressure through the kidney which makes it filter out waste products (e.g., BUN and creatinine) more efficiently.

When the patient’s T4 level is returned to normal – regardless of treatment choice – underlying kidney disease may be unmasked.

It is very important to understand that treating the hyperthyroid state did not cause kidney disease.

In addition to the increased blood flow making the patient’s lab values look better than they might end up being post-treatment for hyperthyroidism, hyperthyroid cats have less muscle mass than healthy cats and since creatinine comes from internal muscle breakdown (a normal daily occurrence), a skinny kitty is going to generate less creatinine – making his kidneys look better than they really are.

Once the treated hyperthyroid cat starts to regain his muscle mass, the creatinine value may rise – leading the clinician to erroneously assume that the kidneys have worsened.

Again, the underlying kidney disease is being masked by the hyperthyroidism but it is critical to understand that treating a cat for hyperthyroidism does not actually cause kidney disease.

Quite the contrary.

Recent research has shown that the negative effects (including the increase in blood pressure at the kidney level) of an increased metabolic rate may very well contribute to the development and progression of kidney disease in the untreated hyperthyroid cat.

While it may be tempting to leave a hyperthyroid cat either untreated or undertreated with very low levels of anti-thyroid medication, this can have a negative effect on kidney health, as well as heart health.

Many veterinarians shy away from I-131 or surgery versus anti-thyroid medication and Hill’s y/d because the first two are permanent and the last two are temporary. Their argument is that the medication dosage can be lowered or discontinued and the diet can be changed if they don’t like how the kidney values look once the T4 is lowered to the normal range.

But the idea of lowering the dosage of an anti-thyroid medication or altering the diet to let the patient ‘run hot’ so that the kidneys look better is not without its very unhealthy consequences.

Remember that hyperthyroidism is revving up your cat’s ‘engine’ (metabolic rate) damaging the entire body, including the kidneys.

The heart is another vital organ that suffers with this disease since it is basically wearing itself out by its increased rate of pumping.

I try very hard not to fall into the trap of ‘tunnel vision’ medicine.  I focus on the whole body and, for that reason, I will repeat this statement:

I-131 is the only choice I will consider for my own cats.

If the I-131 unmasked kidney disease that was not apparent when their metabolic engine was in high gear, I would just deal with the CKD as needed.

Some readers may be familiar with a ‘methimazole (Tapazole) trial’ whereby the patient is put on this anti-thyroid medication to return the patient’s T4 level back to normal which often happens within 2-4 weeks.  Once the T4 level is back to normal, the kidney values (BUN, creatinine, etc.) are assessed.

This trial is basically showing us what the kidney values will most likely be after effective I-131 treatment but in a reversible manner.

Even though this is definitely not the protocol that I would follow for my own cats – since I am going to treat their hyperthyroidism with I-131 no matter what their kidney values are – I do offer it as an option for my clients so that there are no surprises regarding kidney function after the I-131 treatment.

It is important for some clients to know what the kidney values may be after the T4 returns to a normal level but most of them forego the methimazole trial and go right to I-131 when hearing that this is how I treat my own cats.

I have never heard any client express regret for skipping the trial.

Note that the experts in this field who I have spoken with have recently tended toward slightly lower doses of I-131 for cats with significant kidney disease so that the T4 is more likely to end up in the upper part of the desired range versus the lower part. Therefore, please discuss the issue of dosage with the doctor administering the I-131 to your cat.

It must be understood that it is impossible to know the exact dosage that will result in your cat’s T4 ending up in the higher end of the desired range versus the lower end.  Therefore, there is always a chance that a lower dosage of I-131 may not be enough to cure the hyperthyroidism and your cat’s T4 will still be too high.  In these cases, the treatment will need to be repeated at additional expense.

September 2012
Updated October 2014
Updated November 2016
Lisa A. Pierson, DVM

Lisa A. Pierson, DVM

Hello CatInfo readers,

I am often asked what led to the creation of catinfo.org and what fuels my passion for doing as much as I can to help cats from all over the world live long and healthy lives.

The second part of the question is easy to answer: I really love cats.

The first part of the question takes a bit more explaining.

I never imagined that I would become such an outspoken veterinarian regarding matters of optimal feline nutrition and care given that my primary focus straight out of veterinary school was equine medicine.  I never dreamed that I would end up writing pages and pages detailing how to make a healthy diet for cats, or passionately discussing the prevention and management of feline diabetes and urinary tract diseases, or writing about the dangers of ‘dry pilling’ cats, or putting a litter box-cleaning video on the internet especially considering the fact that the World Wide Web was years away from even existing when I graduated from the University of California, Davis School of Veterinary Medicine in 1984!

So how did I become so deeply passionate about cat nutrition, general care, and the various medical conditions that affect the cats that we share our lives with?

Austin, Robbie, and Anne Jablonski.

Let’s start with Austin who I am pretty sure was a long lost love from a former life.  I adopted Austin from a shelter when he was 4 years old.  His time was running out and I am a sucker for the adults that nobody wants.  Plus, brown tabbies really do something for me.  Our hearts were instantly connected and when I had to say goodbye to him in 1998, I was devastated.  I still cry over him.

After losing Austin, I wanted to do something to honor him so I started volunteering with a local cat rescue organization, TLC Adoptions, to pay tribute to my very sweet boy. Over the next 13 years, I rescued and placed approximately 550 cats and kittens in homes. Unfortunately, I saw very quickly that we could never adopt our way out of the overpopulation crisis since the math just does not add up.  There are FAR more kittens being born each minute than there are available homes.

The answer lies in getting humans to become more responsible about spaying and neutering.

During my years of involvement in the rescue world, I spent many long hours doing TNR work (Trap/Neuter/Return) of feral (wild/unowned) cats in order to prevent the suffering endured by homeless cats and kittens living in a concrete jungle, and to try to make a dent in the large number of unwanted kitties that lose their lives in shelters every day.

I would often go on periodic 3-4 day-long trapping marathons to stabilize large feral colonies using traps that I designed and built for increased efficiency.   This would entail starting to trap at around 7 or 8 PM, staying out until 4 or 5 AM, then performing surgery until all of the cats were spayed or neutered.  After a few hours of sleep, I would get up and start all over again.

I wish that I could say that rescue work is all about warm and fuzzy feelings – and no sadness – but that could not be further from the reality of the situation.  After spending 13 years heavily involved in rescue work – and having it exact a tremendous toll on my heart – I am now taking a break and concentrating more on helping cats live better lives all around the world through my website.

So how does my precious Robbie fit into this picture?

If not for Robbie this website would probably not exist and I might still be feeding my cats a very unhealthy diet of dry food.  Robbie is the cute brown tabby that adorns the top of all catinfo.org webpages and who, if given the chance, would spend his life wrapped around my neck.

I call Robbie the “best ‘mistake’ of my life.”

I have had many animals grace my life but my bond with Robbie is one of the deepest I have ever had the privilege to experience.  He truly is my furry little soul mate.

Robbie took his first breath at 1 AM on April 6, 2001 when, at the last minute, I decided to do a C-section on his feral mother.  I had spayed 6 pregnant cats the day before and was emotionally spent over the death of 27 kittens.  I was exhausted at that late hour and it would have been much easier to perform a routine spay on Robbie’s mother but I simply could not take the life of one more living creature.

It is necessary in rescue work to spay pregnant cats. This is a fact of life given the lack of available homes. I had spayed many pregnant cats in the years before Robbie’s birth and I have spayed many more since then but that night a split second decision was made to bring Robbie into the world and he has been my constant companion ever since.

I immediately called my decision a “mistake” because bottle feeding 6 newborns was not an easy task but Robbie has quite literally changed my life so it is a decision I have never regretted.

Ok, so who is Anne Jablonski and how does she figure into the creation of catinfo.org?

Robbie had been dealing with diarrhea for most of his life and being the dutiful vet that I was, I tried every prescription diet available.  None of them helped and I now cringe and get angry when looking at the ingredients through much more knowledgeable eyes.  Now that I know what it means to be an obligate carnivore with a low thirst drive, I would have to be stranded on a desert island with no other food source to consider putting those diets into a cat’s food bowl.

In December, 2002, at the suggestion of a friend of mine, I joined the Yahoo IBD group out of desperation.  Nothing the veterinary community had to offer was helping – including the poor quality prescription diets, steroids, metronidazole, etc.

At the time, I was feeding all of my cats a combination of Hill’s Science Diet Light dry food and Iams Less Active dry food with some NutroMax dry thrown in for variety.  No canned food was fed because I came from the ‘old school’ which is full of not-terribly-well-educated people, like myself at the time, who feel that dry food is healthier than canned food.

Unfortunately for our cats, this could not be further from the truth and when humans starts to realize this, we will have fewer sick cats in our world.

Anne was the co-moderator of the IBD group and after a warm welcome, she said in her  always-polite delivery……“Um….Dr. Pierson….do you think you might consider feeding your cats a better diet?”

Since I have never had much of an ‘I-am-the-doctor-and-know-better’ type of ego, I listened carefully to what she had to say after replying “Really?  Hill’s Science Diet is not a healthy food?  But it says right on the label that it is ‘Veterinarian Recommended’!”

Side note:  Sadly, many of my colleagues do, indeed, recommend products made by Hill’s (and Purina) and this is a testament to the fact that most veterinarians are not well-versed in proper feline nutrition and simply defer to companies like Hill’s and Purina whose marketing budgets are huge.  These large budgets include substantial sums of money dedicated to sponsoring – including very heavy advertising – our professional meetings and infiltrating veterinary schools to get students ‘married’ to their products.

Coincidentally, just after Anne’s comment, I picked up our profession’s most recent Journal of American Veterinary Medical Association (the Dec. 1, 2002 issue) which contained, under Timely Topics in Nutrition, Dr. Debra Zoran’s wonderful article entitled The Carnivore Connection to Nutrition in Cats.

I immediately read it and a light bulb came on over my head.

I went to the cupboard and read the ingredients on the bags of dry food and also noted the low moisture content while keeping in mind that cats have an inherently low thirst drive and are designed to get water with their food.

I cringed.

So, do some cats live long lives on this type of diet?  Yes, they do but I am more interested in feeding a diet that promotes thriving and not simply surviving.

I want to feed a diet that gives my cats the best chance of avoiding gastrointestinal disturbances, diabetes, obesity, and urinary tract diseases – including life-threatening and painful urethral blockages and bladder inflammation (cystitis).

One of the most important pages on this website is the Urinary Tract Health page which states:

If I could have the reader of this webpage take away just one word from this discussion, it would be “water“.  If your cat is on a properly hydrated diet of 100% canned food – and no dry food – you stand a very good chance of never needing to read this webpage.”

Think of canned food as flushing out your cat’s the bladder several times a day.  If the bladder is ‘rinsed out’ frequently, your cat is much less apt to suffer like Opie did as shown below.

A very smart veterinary urologist has stated:  “Dilution is the solution to the pollution.”  This means that water flowing through the bladder will dilute crystals, protein, mucus, and cellular debris in the bladder.  This “pollution” comprises material that could turn into stones/plugs that would block the cat’s urethra.

Please do not make the very common statement:  “But my cat drinks a lot of water so I know he is getting enough!”

Cats have a very low thirst drive and it has been shown that they consume approximately double the amount of water when fed canned food (78% water) versus dry food (10% water).  This is taking into consideration the water they consume from their food plus the water bowl but please note that cats on canned food rarely drink.  This is because they are on a properly hydrated diet and are getting a large amount of water through their food.

This issue  becomes clearer when we understand that a cat’s normal prey is ~70% water and they evolved as a desert dwelling species.  If prey was available, their extra water needs were minimal.

Opie is a painful example of the suffering often caused by dry food.

He was a stray cat that would have died a very slow, painful, and miserable death if TLC Adoptions had not rescued him in 2008.

There is nothing in bags of cooked-to-death, water-depleted, heavily plant-based protein, high carbohydrate diets that makes any sense to me.

Nothing about dry cat food comes close to resembling the properly-hydrated, low carb, animal protein diet that a cat is designed to eat.  When looking at bags of dry food, I see plenty of moisture-deficient species-inappropriate, profit margin-driven ingredients that make the stockholders of pet food companies very happy.

Dry foods are also contaminated with bacteria, storage mites, and dangerous – and life-threatening – mold spores and toxins which make cats sick more often than people realize. 

Vomiting and diarrhea are very common feline problems that veterinarians deal with on a daily basis.  However, it amazes me how infrequently the food – especially dry food – is looked at as a source of the patient’s illness.

Thanks to Anne and Dr. Zoran’s article, I made a firm commitment on December 22, 2002 to start working toward removing all dry food from my cats’ diet.

Unfortunately, my 7 cats at the time had other ideas.  They ranged in age from 1.5 – 10 years and had been fed a 100% dry food diet for their entire lives.  I had 7 die-hard kibble addicts on my hands which made for a VERY frustrating next 3 months.

See Tips for Transitioning Dry Food Addicts to Canned Food which emphasizes using patience, time, and tricks to get cats off of all dry food.

By March, 2003, I had won the battle and had gotten all dry food out of my house.  My cats had finally found their inner carnivore and were eating a 100% canned food diet.  They now had more energy and the overweight ones were slimming down.

And most importantly, Robbie’s diarrhea had vastly improved.

I was happy that my four-legged family was finally eating a water-rich diet with low carbohydrates, and meat (not plants) as their protein source but I was becoming frustrated over the lack of control that I had with respect to the ingredient quality and composition (the caloric distribution between protein, fat, and carbohydrate) of commercial canned foods.

With Anne’s guidance, I started making my own cat food.  To be honest, I felt liberated with my newfound control over what was going into my cats’ food bowls and, for the first time in his life, Robbie had formed stools!

Interestingly, my Making Cat Food page is the second most visited page on this site – second only to the Feeding Your Cat: Know the Basics of Feline Nutrition page.  I am pleasantly surprised to know that there are so many people willing to make cat food!

Making your cat’s food may sound like a daunting task but if you knew what an idiot I am in the kitchen you would be impressed by just how easy it is.

If I can make cat food, anybody can.

I spend a few hours in the kitchen (my least favorite room in the house) 4-6 times each year making the food which then goes into the freezer.  For me, this is a very small amount of time out of my life to ensure that I have complete control over what goes into my cats’ food bowls.

That said, my goal with this site is simply to get people to stop feeding dry food and to switch to canned food.  As noted on my Commercial Canned Cat Food page, I would MUCH rather see someone feed the cheapest canned food (Friskies, etc.) than the most expensive dry food.

Why?  Because nearly all canned foods address the 3 main issues with feeding cats:

1) They all contain an appropriate amount of water for a species with a low thirst drive – so cats won’t have to suffer like Opie did.

2) Most canned foods are low in carbohydrates (Hill’s products and some Purina products are notable exceptions).

3) The protein is more apt to come from meat and not plants (grains/vegetables).

So, in summary, my love of Austin led me to rescue work which resulted in Robbie entering my life.  Robbie’s chronic diarrhea led me to Anne.  And because of Anne’s gentle nudging, I began to look at the food I was putting into my best friends’ food bowls with a more critical eye.

And my deep love of cats and keen interest in internal medicine and nutrition led to the creation of catinfo.org.

As my time permits, I will continue to write new articles for this site as well as update current writings.

I’m often asked why I don’t write a book.  My reason?  We never stop learning and growing.  Once something is in print, it cannot be updated – unlike this website.

You will notice that there is a date at the bottom of every page showing when the last revision was written.  Keeping the site current is extremely time consuming but I do my best as time permits.

Thanks to all of you and your quest for knowledge, this website has become quite popular with approximately 3 million visitors each year.  Many of you have added a link to catinfo.org on your own websites which has resulted in more cats getting fed and cared for optimally.

If you have found your way to this site, your cats are very lucky to have you care deeply enough about their well-being to put the time in to research ways to promote optimal feline health.  It is my hope that the information contained here will improve the quality and length of your cat’s life.

Happy reading!

Dr. Pierson and Robbie

September 2011
Reviewed November 2016
 Lisa A. Pierson, DVM

Lisa A. Pierson, DVM

   French translation
   Spanish translation

Lower urinary tract clinical signs

Cystitis

Urethral obstruction/Opie’s story

Urinary tract infection

Urinalysis/Dietary issues

Prescription diets

Lower Urinary Tract Clinical Signs

Patients may exhibit one more more of these signs:

• Straining to urinate – with and without production of urine
• Frequent trips to the litter box – with and without production of urine
• Crying while urinating
• Excessive licking of the genital area
• Blood in the urine
• Urinating in places other than in the litter box
• Posturing (squatting) in the litter box for a long period of time  (Note that sometimes people think that their cat is constipated when he/she is really showing signs of a lower urinary tract problem.)

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Cystitis

Cystitis, also known as Interstitial Cystitis, refers to inflammation of the bladder wall leading to painful, frequent voiding of small amounts of urine.  This is one reason why clumping (scoopable) litters should be used.  Scoopable litters will enable the feline caregiver to keep track of the size of the urine clumps to see if they are smaller than usual, as well as the number of urine clumps to determine if the cat is urinating more frequently than usual.

Cats with cystitis will often have many small urine balls in the litter box.

If the cystitis is severe enough, there will be blood in the urine but this blood is not readily apparent once the urine is voided into the litter.

Important:  The presence of blood in the urine does *not* necessarily mean that an infection is present.

Cystitis can be a very painful condition!  The patient will often start to associate the litter box with his/her pain.  This can lead to litter box aversion which causes the patient to urinate elsewhere.  In these cases, there may be fewer urine balls in the litter box than usual.

Important:  These cats need pain medication such as buprenorphine (Buprenex).

What causes cystitis?  I wish that the veterinary community knew the answer to that question in all cases.

What we do know is that cystitis often appears to be linked to stress.  The highly concentrated urine that results from being fed a water-depleted (dry food) diet may also be a significant factor in some cats.  The concentration of urine is reflected by the urine specific gravity (USG) number found on the urinalysis report. The higher the number, the more concentrated the urine.

(See the Urinalysis/Dietary Issues section below for information and a video regarding how to obtain a urine sample from your cat for a USG measurement.)

We know that bladders are ‘happier’ with more water flowing through them which helps to flush out debris (mucus, cells, crystals) and keep the urine diluted.  Dilute urine is thought to be less irritating to the bladder wall.  Therefore, we see far more cases of cystitis in dry food-fed cats than in cats eating canned food.

We also know that 99% of cystitis cases in otherwise-healthy patients are *not* due to a bladder infection – contrary to popular belief.  The erroneous belief that cystitis is always secondary to an infection leads to the rampant abuse of antibiotics.

It is very troubling to witness the very common practice of ‘shotgun’ treating these patients with antibiotics when most of these cases are sterile (sterile = no infection) cystitis.

It is also very frustrating to see these poor cats leaving the veterinary clinic with no pain medication!

To repeat:  We know that stress plays an important role in the cause of cystitis.  Can you think of anything more stressful than pain?

See the vicious cycle?  Stress can cause cystitis.  Cystitis is painful.  Pain is very stressful.

Crystals are not thought to be a significant cause of cystitis.  This is another very common misconception among both lay people and veterinarians leading to, in many cases, inappropriate usage of acidifying prescription diets which can potentially lead to calcium oxalate stones and exacerbate the bladder inflammation.

That said, dietary management must be considered on a case-by-case basis and one-size-fits-all recommendations with respect to diet composition cannot be given.  That said, I will give one ‘one-size-DOES-fit-all’ statement and that is “canned food is always better than dry food due to the appropriate water content in canned foods.”

Bladder stones (aka “uroliths” or “cystoliths”) may or may not contribute to cystitis.  However, it is important to examine the urinary tract with radiographs or ultrasound to look for stones.  Due to the expense, some people opt to not radiograph or ultrasound the cat on the first visit but, given how common stones are, I would highly recommend checking for stones even on the first visit.

Radiographs and ultrasound each have their pros and cons with respect to imaging the urinary tract and the accuracy/usefulness of each examination method depends on the quality of the equipment and the skill of the operator.

Radiographs – providing there is not a lot of stool in the colon to obscure the view – may reveal a stone in the urethra, whereas U/S will not show this area.

Ultrasound exams have some benefits over radiographs but it is also very highly dependent on operator skill.  Ultrasound can pick up stones that may not show up on radiographs.

In some complicated cases, both imaging methods are needed to obtain a diagnosis.

Andrew

Treatments for sterile cystitis include:

1. Pain medication;
2. increasing water consumption with a canned food diet, etc.;
3. decrease the patient’s stress – not always easy since cats can be very ‘silent’ in their stress and we may not always be aware of what is bothering them;
4. glucosamine/chondroitin sulfate/hyaluronic acid products such as Cosequin or Trixsyn may help but studies have not supported them as being beneficial. That said, they don’t seem to have any downsides and may be worth a try.

Tricks used to increase water consumption:

1. water fountain;
2. flavored waters such as tuna water, chicken or beef broth, clam juice, lactose-free cat milk (CatSip), etc. – can be kept in covered (to prolong fresh smell and taste) ice cube trays or frozen in uncovered trays and then transferred to ziplock bags;
3. add plain water to canned food – ~1 TBS per meal – or whatever amount your cat likes.

You can make your own tuna water by taking a can of tuna and adding 3 cups of water. Break up the tuna and let it sit for awhile (~15 minutes, give or take) and then pour the tuna water into covered ice cube trays.

3 cups of water fills two 16-cube trays.

After warming the flavored ice cubes to ‘mouse body’ temperature you can:

1. add to canned food or
2. set out as a separate drink of water.

Subcutaneous fluids may also need to be administered at home by the owner in order to increase urine flow.  However, this can be stressful and is usually reserved only for severe cystitis cases involving dry food addicts that are on their way to transitioning to canned food.

To repeat a very important point:  Bladder infections are not a common cause of cystitis.  Sadly, the rampant abuse of antibiotics when addressing feline urinary tract issues in cats shows that this fact is being ignored.  The most important ‘treatments’ are increasing water consumption and lowering stress.

Cats, unlike other species including humans, have a natural defense mechanism in which they produce a more highly concentrated urine. (USG >1.040)  Few self-respecting bacteria want to float around in concentrated cat urine.

Before considering the use of antibiotics in cystitis patients,  a culture and sensitivity (C & S), in addition to a standard urinalysis,  should be run on urine obtained via cystocentesis.  This involves a needle going through the abdominal wall, directly into the bladder. This sounds much worse than it really is.  The patient does not feel the needle going in but, instead, may simply object to being held on his or her back.

Free-catch urine samples (urine voided onto an exam table or into a litter box) should not be used for a C & S due to the issue of contamination which will often give a false positive result.  In other words, bacteria will grow on the culture that may not even be in the patient’s bladder or kidney.

The ‘culture’ part of this test shows if an infection exists or not. The ‘sensitivity’ part of the test is run only if a bacterial colony grows.  This half of the test tells us which antibiotic is the best one to choose for the type of bacteria that was grown.

One difficulty that we run into when trying to get a ‘clean’ sample (via cystocentesis) from a cystitis patient is that most of these patients present with an empty bladder.  Or, they void all of their urine once the veterinarian starts to palpate (feel) the bladder through the abdominal wall.

To get around this, the patient can be given a dose of pain medication and some subcutaneous fluids and placed in a cage without a litter box for 1-3 hours. This should result in the patient’s bladder filling up enough to obtain a sample for a urinalysis and a C & S.

Please ask your vet to put your cat in a cage in the quietest part of the hospital and put a towel over the cage door to decrease stress.

A note about cost:  Many  veterinarians do not run a C & S on their cystitis patients because they are worried about running up a client’s bill.  However, I cannot stress strongly enough that this is often a pay me now or pay me later issue.

I have seen countless cases where both the veterinarian and the client are ‘chasing their tail’ by pouring needless antibiotics into their sterile cystitis patients. This not only results in added expense and stress for the client, but please also consider the added stress to the patient’s mind and body and the significant potential for promoting bacterial resistance.  Most cats are not happy about taking medications and all medications have negative side-effects. 

This “tail chasing” often results in far more cost to the client than would have been incurred if a C & S would have been run when the patient first presented with clinical signs.

There is a joke in veterinary medicine that states:  “Sterile cystitis patients get better in 1 week with antibiotics and in 7 days without antibiotics.”

The good news is that cystitis often resolves within a few days to a week.

The bad news is that it tends to recur – especially in patients that are fed dry food and/or continue to live in a stressful environment.

See below for further discussion of Urinary Tract Infections.

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Urethral Obstruction – Opie’s Story

The urethra is the tube that drains urine from the bladder to the outside.  It can be partially or completely blocked with mucus, stones, inflammatory cells, or crystals.  This is a life-threatening – and very painful – condition which can result in the bladder rupturing within 24 hours of a complete urethral obstruction – leading to death soon after.

Any cat that is repeatedly entering the litter box but not voiding any urine is in need of IMMEDIATE medical attention!  This is one reason why it is so important to use a clumping (scoopable) litter.  Clumping litter allows you to see just how much, if any, urine is being voided.

Males are much more prone to blocking than females because the male urethra is much longer and more narrow than a female’s.

The following pictorial shows what Opie had to go through when he blocked. It is highly unlikely that he would have had to suffer like this if he had been fed a proper, species-appropriate diet of water-rich canned food instead of dry food.  Opie was found lying in a backyard crying – minutes away from rupturing his bladder due to a urethral obstruction.

A one week stay in the emergency clinic resulted in a $4,000 vet bill.  Another $350 bill was incurred 3 weeks later when Opie had to have a stricture broken down in his urethra.  Catheterization of the delicate urethra can damage the tissues and result in a stricture which will obstruct urine flow.  Repeated catheterizations can set your cat up for serious problems.

Opie’s case is a very good illustration of the fact that proper nutrition (NO dry food) is a ‘pay me now or pay me later’ issue.

Opie was sedated and a catheter was passed up his urethra in order to break up the obstruction before his bladder ruptured.  His bladder was then flushed to try to remove any debris that could cause him to block again.

Is it possible for a cat to block when on a 100% canned food diet?  Yes, it is possible, but it is highly unlikely.  When water is flowing through the bladder, crystals, mucus, and cellular debris will be much less apt to build up and cause an obstruction.

Also, when water is flowing through the bladder, the urine is more dilute which is thought to be less irritating to the bladder wall in some cats.  Less irritation means less inflammatory cells and mucus to block the urethra.

Think of canned food as rinsing out your cat’s bladder many times each day.

A procedure called a perineal urethrostomy (PU) is often performed on blocked cats with the hope of preventing future obstructions.

A PU removes the penis and part of the urethra and leaves the patient very prone to urinary tract infections for the rest of his life.  Also, the surgery site can stricture at a later time.

I strongly believe that this procedure is performed far too early in many cases before a properly hydrated diet is tried.  Please give this procedure a lot of thought before consenting to it.

In December 2012 I consulted with 6 owners of blocked cats over a 10-day period of time. (Yes, this cause of suffering is that common…)  Unfortunately, one was unable to get to a veterinarian in time and his bladder ruptured resulting in a very slow and painful death.

The other 5 cases were being threatened with penis amputation (PU surgery) by the primary care veterinarian.  I am happy to report that, one year later, all cats are doing well – with their penis intact.  They are, of course, eating only a water-rich, low mineral, diet and no dry food.

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Urinary Tract Infection

Urinary tract infections can occur anywhere along the tract from the kidneys to the urethra.  Most infections gain access to the bladder when bacteria travel up the urethra from the outside world.  From the bladder, the infection can ascend to the kidneys.

Please note that when the abbreviation “UTI” is used, the ‘I’ must be defined. Does “I” mean infection?  Or does it mean inflammation?

It is very important to understand the difference if we are to stop overusing antibiotics and start using more pain medications when cats exhibit signs of urinary tract problems.

Studies have shown that otherwise healthy cats (no kidney disease, diabetes, or hyperthyroidism) – that are showing signs of urinary tract discomfort – have only a ~1-2% chance of having a UT infection yet antibiotics are prescribed very frequently for these patients.  The veterinary (as well as human) medical community needs to address this very serious problem involving the overuse/abuse of antibiotics.

Roughly 99% of these otherwise healthy cats have sterile (no infection) cystitis.  This is because the feline is very good at saving water to stay hydrated which results in a very concentrated urine. (Urine Specific Gravity [USG] >1.040)  Concentrated urine is a very hostile environment that does not readily support bacterial growth.  Therefore……

Urinary tract infections are rare in cats without a concurrent disease such as kidney insufficiency, diabetes, or hyperthyroidism.

What about the other population of cats with diseases such as kidney insufficiency, diabetes, or hyperthyroidism?  Cats with chronic kidney disease (CKD) and hyperthyroidism often produce a more dilute urine (USG <1.030) which is a friendlier environment for bacteria.  Unregulated diabetic cats often have glucose (sugar) in their urine which makes a nice culture medium for bacteria.

However, even cats with CKD, hyperthyroidism, or diabetes that are showing signs of lower urinary tract disease have a less than 30% chance of having a urinary tract infection.  (Several studies have been done in this area and the results have varied but all have shown less than 30%.)  This fact illustrates why it is very important to run a culture and sensitivity.

Urine Culture and Sensitivity (C & S)

As described above in the Cystitis section, this is a two-part test that is used to check to see if an infection is present (culture) and what antibiotic(s) would be the most appropriate to use for the strain(s) of bacteria present (sensitivity).

Please note that I emphasized “if” in the previous sentence.  It is very important to confirm that an infection actually exists rather than to subject your cat to the administration of an unnecessary, and potentially dangerous, antibiotic without proof that it is needed and is the correct one.

Culture results are reported over a period of 3 days – at a minimum.  The typical sterile cystitis report will read:

24 hours – no growth

48 hours – no growth

72 hours – no growth

If there is an infection present, the report will read something like “moderate growth of e.coli – sensitivity pending.”  This means that the next report will give your veterinarian important information necessary to pick the best antibiotic for your cat’s infection.

Cultures can be classified in 3 ways:

1) diagnostic – the initial culture before starting antibiotics to confirm that an infection is present and to identify the bacteria, assess the number of bacterial colonies to quantify the level of infection (cfu – colony forming units per milliliter of urine), and to determine the organisms’ susceptibility to various antibiotics

2) therapeutic – performed 3-5 days after starting antibiotics (after a positive diagnostic culture) to assess antibiotic efficacy or it is sometimes performed 3-5 days before cessation of antibiotic administration

3) surveillance – performed 7-14 days after the last antibiotic dose to check for relapse or re-infection

Relapses are defined as recurrences caused by the same species and strain of microorganism that were found in the diagnostic culture within several weeks of stopping antibiotic therapy.

Re-infections are defined as recurrent UT infections caused by a different organism. The only way you can differentiate relapses from re-infections is to compare the results of the initial culture obtained prior to antibiotic usage to those of cultures obtained during and/or after discontinuation of the antibiotic.

Relapses represent a possible antibiotic treatment failure that may have resulted from improper antibiotic choice, dose and duration of therapy, lack of owner or patient compliance, failure of the patient to absorb an orally administered drug, deep-seated infections, failure to identify predisposing factors, or acquired drug resistance.

Re-infections, on the other hand, usually represents failure to recognize and eliminate predisposing factors associated with continuing dysfunction of host defenses, or UT infections caused by procedures such as catheterization or perineal urethrostomy (PU) surgery. Frequent re-infection is an absolute indication to evaluate the patient for anatomic, metabolic, and immunologic disorders that may compromise normal host defenses.

It is important to understand that when a cat has had his penis amputated (PU surgery) a vital barrier to infection has been removed.

For a patient’s first time infection, therapeutic and surveillance cultures are not usually performed due to cost and added stress for the patient.  However, they should be considered in all recurrent UT infection cases, otherwise the veterinarian and owner may find themselves running in circles.

To repeat an important point:  Cats with a urine specific gravity above ~1.040 have a very low chance (~1-2%) of having a urinary tract infection.

Cats with a USG below ~1.030 have a higher chance of having an infection.

If a patient presents with lower urinary tract signs, and has a low urine specific gravity or is a diabetic cat that is spilling sugar in his urine, and if an in-house analysis of the urine indicates that an infection may be present, the patient may be started on a broad spectrum antibiotic pending the C & S result.

If the culture turns up negative, the antibiotic can be discontinued.  Or if the culture comes up positive but shows that the bacteria are resistant to the antibiotic that has been chosen, the correct antibiotic can be started.

At least in these cases, the needless – or wrong – antibiotic will have been given for only 3 days instead of for a much longer period of time.

An important note regarding the long-acting antibiotic called Convenia:

Because this drug stays in the body for a very long time (up to ~60 days) it is one of the newest antibiotics to be terribly overused/abused.  Veterinarians and lay people are seeing it as a quick and easy fix to their problems because they don’t have to give it once or twice daily like with other antibiotics.  It is typically given by injection.  If a second one is administered, it is given again in 2 weeks. However, keep in mind that if an adverse reaction occurs, you cannot retrieve the drug from the body.

Convenia can cause severe anemia, as well as other serious health problems.  (Please see the Convenia – Worth the Risk? webpage on this site.)  There is a report on VIN (Veterinary Information Network) from a general practitioner who dealt with two cats that died within 10 days of receiving Convenia.  They were otherwise healthy cats and had normal red blood cell counts prior to receiving Convenia.  There is no absolute proof that Convenia caused their deaths but there is an extremely high index of suspicion that this drug was the culprit since this class of drugs is known to cause anemia.

I also dealt with case of severe anemia post-Convenia in an otherwise healthy cat.  The emergency clinic was able to save the patient’s life after a 1 week stay in the hospital.  The bill was over $6,000.

Please do not allow this drug to be given if the cat is able to be medicated with a safer antibiotic.

Baytril is another antibiotic that is frequently overused. This drug can cause blindness (very rarely) so I do not take its use lightly.

Clavamox is the most common broad-spectrum antibiotic that is administered to cats.  It causes vomiting and/or diarrhea in some cats but it is one of the safer choices of antibiotics.  It comes in pill or liquid form. I greatly prefer the pills because they are very palatable and can be crushed and added to canned food, or administered in a small piece of a Pill Pocket.

Never use a whole Pill Pocket since they are too large making it far more likely that the cat will bite down on the pill versus swallowing it whole.  I do not like ‘pilling’ cats so if your cat will not eat crushed clavamox tablets in tasty canned food or baby food or in a Pill Pocket, then use the liquid formulation.  (See the Pilling Cats webpage on this site.

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Urinalysis/Dietary Issues

Laboratory analysis of urine (UA) can be done on samples obtained in various ways but you need to be aware that some tests are not accurate on free-catch samples that you have obtained at home.

Due to the delay in testing of the sample (by more than 30 minutes once the urine has been voided), temperature changes, and the lack of sterility of a free-catch sample, interpretation of a urine sample obtained at home can be very misleading.

One example of a test that is accurate is the urine specific gravity.  This is also one of the most important numbers on the UA.  I routinely (3-4x/year) check my cats’ USG from free-catch samples obtained by slipping a flat (versus a deep/narrow) tablespoon under them when they are urinating.

A low USG can be an early indication of kidney insufficiency so I like to monitor any cat over 10 years of age several times each year.

Watch this video for information regarding obtaining free-catch urine samples:

When assessing a patient’s urine concentrating status, it is always much better to take multiple readings so that you can see an average over time – versus relying on just one reading, at one static point in time, from a UA report.  Therefore, some people buy their own refractometer in order to check their cat’s USG at home.  If you do purchase one, make sure that it is labeled for use with urine.  The RHC-200 ATC (automatic temperature compensation) linked here has been sold on eBay for as little as $50.

The RHCN-200 ATC is billed as a “Heavy Duty Version of the RHC-200 ATC and features an easy-to-calibrate knob” versus the need to use a small screwdriver (easily lost or misplaced) for the RHC-200 ATC model.  Either one will be fine because you don’t have to calibrate the unit very often.  In fact, my 36 year old one has only been calibrated a few times in its life but I would suggest that you calibrate yours ~once or twice a year with distilled water which will have a specific gravity of 1.000.  Calibration is very easy.  Just apply a couple of drops of distilled water onto the refractometer window then adjust the refractor line to 1.000 with the screwdriver or the knob.

A urine culture and sensitivity is not accurate from a free-catch sample due to contamination issues.  However, on rare occasions we may run a C & S from a midstream sample that is caught in a sterile container but interpretation must take into consideration the collection method.  If the C & S comes back negative on a free-catch sample, this result is helpful but if it comes back positive, you cannot be sure if the bacteria are from the bladder/kidney or from the very end of the urinary tract or the patient’s hair that surrounds the vulva or penis.

A check for crystals is also not accurate because crystals can form once outside of the bladder in as quickly as 20 – 30 minutes.  This problem of a ‘false positive’ can be an issue with urine obtained from a free-catch sample at home, as well as one obtained via cystocentesis that is sent to an outside lab due to the same time delay.  If your vet wants to accurately assess for crystals, the urine must be looked at ‘in-house’ within 20 – 30 minutes of cystocentesis or the urine being voided.

pH also may not be accurate in urine samples obtained at home.

A cystocentesis is the best method to obtain urine which will yield the most accurate results.

A few definitions, along with comments:

pH:

pH refers to the acidity or alkalinity of, in this case, urine.  pH is often mentioned when discussing diet and crystals but is focused on far too heavily.

While keeping in mind that cats are obligate carnivores (see Feeding Your Cat: Know the Basics of Feline Nutrition), it is important to understand that a meat-based (carnivorous) diet naturally leads to an mildly acidic urine.

Grains, on the other hand, promote a more alkaline urine due to their carbohydrate level as shown by this study.

Due to humans’ focus on profit margin, diets higher in grains (higher in carbohydrates than a cat’s natural diet) have flooded the market – along with pet food manufacturers’ unscrupulous advertising onslaught designed to persuade the feline caregiver to think that feeding a water-depleted, grain-laden dry food diet constitutes optimal nutrition.

Keep in mind: Meat is expensive.  Grains are cheap.

Meat (animal-based protein) promotes a mildly acidic urine which is normal for the cat.

Grains (plant-based protein and high carbohydrate content) promote an alkaline urine.

As mentioned below in the Crystal section, struvite crystals are more apt to form in an alkaline urine and calcium oxalate crystals are more apt to form in an acidic urine.  Many ‘urinary tract’ diets – including some of the prescription diets – overly acidify the diet past what would be normal for a cat eating a species-appropriate diet.  These diets can dissolve struvite stones but will lead to other problems, such as calcium oxalate stones, if they are fed past the therapeutic time frame.

Please understand that we would rarely have to address pH or crystals if cats were fed a water-rich diet.  However, due to the fact that humans insist on feeding cats species-inappropriate, water-depleted diets in the dry form because they are cheaper and more convenient to deal with and because many cats are addicted to them, members of this species continue to suffer with urinary tract issues.

For many years, struvite (magnesium, ammonium, and phosphorus) was the predominant mineral mixture found in cat urine due to the species-inappropriate level of grains in cat food.  Knowing this, humans stepped in and started acidifying commercial cat food with things like dl methionine – instead of cutting into profit margin by removing the grains and going back to meat.

The so-called ‘urinary tract formulas’ were born.

Unfortunately, in trying to ‘fix’ a cat’s unnatural alkaline urinary pH – caused by human greed in the first place – pet food manufacturers created even more problems by adding urinary acidifiers in the form of dl methionine, etc., which led to the formation of calcium oxalate (CaO) crystals/stones in many cats.  Suddenly, there were far more patients suffering with CaO crystals/stones than there were patients with struvite crystals/stones.

One of the most serious problems with this fact is that CaO stones can only be removed with surgery. There is no way to dissolve them with dietary manipulation.  Struvite stones, on the other hand, are more amenable to dissolution with dietary manipulation.

Most stones found in the kidney are CaO and since we cannot dissolve them with dietary manipulation and since surgery to remove kidney stones (versus bladder stones) is not a safe option, it is easy to see how damaging the effects of feeding an acidifying diet can be if used for long periods of time.

Other systemic problems, including kidney damage and low potassium, can be seen in conjunction with the feeding of these acidifying diets, as well.

It is also important to note that diet is not the only factor involved in determining urine pH.  The timing of the cat’s meals is also a factor.  ‘Post-prandial alkaline tide’ refers to the fact that urine pH will become more alkaline after eating a large meal. Therefore, it is suggest that cats eat multiple small meals throughout the day to help keep the pH in a normal range.  Small cats in the wild eat 8-10 small meals per day.

pH can also be affected by certain medications, vomiting, chronic kidney disease, urinary tract infection, diet, stress, and as already discussed, the timing of the last meal.

If humans would just go back to feeding cats a species-appropriate diet – i.e. – one that has a water content that mimics a cat’s normal prey and one that is based on meat, not gains – instead of trying to artificially manipulate a species-inappropriate diet of grains by adding acidifiers, the vast majority of urinary tract problems would be solved.

• Crystals are most commonly either calcium oxalate (CaO) or struvite (a mixture of magnesium, ammonium, phosphate).

• Calcium oxalate crystals are more apt to be formed in an acidic environment.

• Struvite crystals are more readily formed in an alkaline environment.

• A small amount of crystals is not an abnormal finding in cat urine and the cat should not be automatically put on a prescription diet such as Hill’s Prescription c/d, etc.

• Crystals are often erroneously diagnosed because they can form once the urine has been removed from the bladder.  Therefore, when urine is sent off to an outside laboratory, or a sample is brought from home, a report of “crystals” is somewhat meaningless since you have no idea if they were actually present within the patient.  This misdiagnosis – and overemphasis of the significance of urinary crystals if they are present in the bladder – leads to the client becoming alarmed and the patient needlessly being put on a low quality – and potentially dangerous – diet such as one of the prescription ‘urinary tract’ diets.

Think of crystals in cat urine like leaves on your driveway.  Both are normal findings.  However, if you never hose (or sweep….during a water shortage :>)) down your driveway, the leaves will build up and then you won’t be able to get your car out of the garage.

If crystals are allowed to build up, the urethra can become blocked leading to a life-threatening situation.  A blocked cat can end up with a ruptured bladder – resulting in death – within 12 -24 hours of complete obstruction.

If there is not enough water flowing through the bladder on a regular basis the following will happen with respect to crystals:

• The urine specific gravity goes up meaning that the urine becomes more concentrated.  When this happens, the crystals are more apt to become ‘super-saturated’ in the urine and form stones.

• Mechanical removal is compromised.  When there is ample water flowing through the bladder the cat will urinate more frequently – voiding up to double the amount of urine per day.  This frequent urination of a higher volume of urine helps to remove the crystals instead of letting them build up to block the urethra.

• If there are large numbers of crystals and the cat also has cystitis (inflammation of the bladder leading to mucus production and cellular debris), the crystals can combine with the mucus and inflammatory cells and make a ‘plug’ that can block the urethra.

Keep in mind that it is very important to have enough large litter boxes with CLEAN clumping (scoopable) litter in accessible places so that your cat is very willing to use them frequently and not ‘hold his urine.’

More frequent voiding of urine will lower the chances of stones being formed and will make the bladder wall less likely to become inflamed.

Litter boxes should always be scooped at least twice daily.

Urine Specific Gravity (USG):

As noted previously on this webpage, USG is a measurement of the concentration of the urine.  It is one of the most important values on the UA report.

USGs should be measured on more than one occasion to check for consistency.  A dilute USG would be around 1.015 (stated “ten fifteen”) or 1.020 (“ten twenty”) and a concentrated urine would be more in the >1.040 range.  A USG between these ranges should be monitored to see if it continues to go lower or starts to rise.

The USG of dry food-fed cats is higher (the urine is more concentrated) than it is for canned food-fed cats.

Robbie

Prescription Diets

Please review what I wrote about diet issues at the top of this page in the grey box and also keep in mind what was discussed above regarding the fact that urine crystals are often erroneously diagnosed and the fact that they are NOT necessarily an abnormal finding that needs to be ‘treated’ with a prescription diet.

If you need help beyond the scope of this webpage I am available for phone consultations but please note that many people write to me asking questions that are already addressed on this webpage.

That said, there is a lot of content here and it can be quite confusing.  Therefore, if you want to address it verbally in more detail and also as it pertains to your own cat, you can contact me for a consultation appointment.

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I do not use use ‘prescription’ diets except in rare cases as noted below.  They are expensive and contain low quality, species-inappropriate ingredients, and are not necessary in most cases of feline urinary tract disease.

I only consider the temporary use of Hill’s canned s/d if I know that the patient has urinary tract stones (“uroliths”), or a large amount of crystals – with a high index of suspicion for them being struvite versus calcium oxalate (CaO).

I tend to reach for canned s/d more readily in a male cat than a female. This is because males are much more prone to a urethral obstruction than females due to their long, narrow urethra.

In these cases, I will consider the use of canned s/d (the most acidifying diet on the market) for a short period of time until the patient shows radiographic or ultrasound evidence of stone dissolution/crystal clearance.  This can take as little time as a few days but may take 1-2 months for large stones.

If the stones are not showing any signs of dissolution once the patient has been on the acidifying diet for 2 – 3 weeks, there is a very good chance that the stones are CaO and keeping them on this diet is only going to make matters worse. This  is why it is so important to monitor the patient with radiographs or ultrasound and urinalyses and to not just leave them on s/d.

Remember, CaO will not dissolve with diet manipulation and Hill’s s/d will actually promote the formation of CaO – creating a dangerous situation.  Surgery is the only way to remove CaO stones and if they form in the kidney (more common than the easier-to-access bladder), they cannot be removed without significant risk to the patient.

‘Sludge’ (cellular debris, mucus, proteinacious material, etc.), can be addressed with simply a water-rich diet (canned or homemade diet with added water) to flush it out but it is possible to have small stones hiding in this mixture that could be missed on radiographs or ultrasound and which could result in urethral blockage.

If your cat has a large amount of sludge in his bladder that you are now addressing with diet (s/d or simply canned/homemade food with added water), be sure to watch him carefully for any signs of a urethral blockage. I would not want to leave a cat like this unattended for more than ~12 hours in case he blocked.

Also note that meat-based diets promote an acidic urine (but not overly acidic like Hill’s s/d) and that carbohydrate-based diets promote an alkaline urine.  Keep in mind that carbohydrates have no logical place in the feline diet.

Other prescription diets such as Hill’s c/d, Royal Canin SO, and Purina UR are diets that do not aggressively acidify the urine like Hill’s s/d does.

Therefore, c/d, SO, and UR can be fed for life but I would not recommend it due to their cost and unhealthy ingredients and species-inappropriate composition.

Hill’s s/d, on the other hand, is NOT safe for long-term feeding and should only be used temporarily.

When urinary tract prescription diets were first formulated, they mainly focused on urinary pH manipulation and magnesium restriction.  In recent years, some of the manufacturers such as Purina and Royal Canin have added salt to their diets to encourage higher water consumption in order to dilute the minerals (crystals).  There is controversy surrounding this practice.

Prescription urinary tract diets come in dry and canned forms but after reading this webpage, hopefully the reader will understand just how illogical it is to add salt to a dry food diet to get the cat to drink more water when the cat should be eating a water-rich diet of canned food in the first place.

For dry food addicts, please see Tips for Transitioning Dry Food Addicts to Canned Food. 

As stated in the first section of this webpage, manipulating the pH of urine is not the most important factor in preventing feline urinary tract diseases yet it is so heavily focused on.

I am finding it increasingly frustrating to watch the veterinary community continue to be fixated on the pH of cat urine and the presence of urinary crystals instead of focusing on the much more important issue of dietary water content.

Veterinarians are exhibiting a serious lack critical thought when prescribing a water-depleted diet to any cat but especially one with urinary tract issues, including kidney disease which is very common in cats. 

Instead of reflexively reaching for the prescription diets when patients present with urinary tract issues, I would like to see the emphasis switch to getting the patient off of all dry food and onto a meat-based canned food with added water.

This diet will help maintain a species-appropriate urine pH and will keep the bladder flushed out.

When I say it is illogical to feed “any” cat a diet of dry food, think about practicing preventative nutrition. Do you really want to wait until your cat develops urinary tract problems before you implement the feeding of a water-rich diet to a species with a naturally low thirst drive?

Think about closing the barn door before the horse is running down the roadway.

Updated: December 2016
Lisa A. Pierson, DVM