Feeding Your Cat: Know the Basics of Feline Nutrition

Lisa A. Pierson, DVM

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Diet is the brick and mortar of health.  This web page lays out some often-ignored principles of feline nutrition and explains why cats have a better chance at optimal health if they are fed a canned food diet instead of dry kibble.  Putting a little thought into what you feed your cat(s) can pay big dividends over their lifetime and very possibly help them avoid serious, painful, and costly illnesses.  An increasing number of nutrition-savvy veterinarians, including board-certified veterinary internists, are now strongly recommending the feeding of canned food instead of dry kibble.

The three key negative issues associated with dry food are:

1) water content is too low

2) carbohydrate load is too high

3) type of protein - too high in plant-based versus animal-based proteins

Please click on the links below to read more about optimal nutrition for cats.

But my cat is "fine" on dry food!

The importance of animal proteins, versus plant proteins

Fresh vs highly processed with synthetic supplements

Problems with carbohydrates in dry cat foods

Cats need water with their food

Reading a pet food ingredient label

Marketing labels

'Prescription/therapeutic' diets

Common medical problems associated with dry food

• Diabetes

• Kidney disease

• Cystitis/Urethral blockage/Urinary tract infection/Crystals

• Inflammatory Bowel Disease

• Hairballs

• Obesity

• Hepatic Lipidosis (fatty liver disease)

• Dental health

• Asthma

The safety of dry food

Tips for Transitioning - Getting dry food addicts to eat canned food

Home prepared raw/semi-cooked and commercial raw meat diets

What I feed to my cats

Some final thoughts

Cats Need Animal-Based Protein 

Cats are obligate (strict) carnivores and are very different from dogs in their nutritional needs. What does it mean to be an ‘obligate carnivore’?  It means that your cat was built by Mother Nature to get her nutritional needs met by the consumption of a large amount of animal-based proteins (meat/organs) and derives much less nutritional support from plant-based proteins (grains/vegetables). It means that cats lack specific metabolic (enzymatic) pathways and cannot utilize plant proteins as efficiently as animal proteins.

It is very important to remember that not all proteins are created equal.

Proteins derived from animal tissues have a complete amino acid profile.  (Amino acids are the building blocks of proteins.  Think of them as pieces of a puzzle.)  Plant-based proteins do not contain the full complement (puzzle pieces) of the critical amino acids required by an obligate carnivore.  The quality and composition of a protein (are all of the puzzle pieces present?) is also referred to as its biological value. 

Humans and dogs can take the pieces of the puzzle in the plant protein and, from those, make the missing pieces.  Cats cannot do this.  This is why humans and dogs can live on a vegetarian diet but cats cannot.  (Note that I do not recommend vegetarian diets for dogs.)

Taurine is one of the most important nutrients present in meat but it is missing from plants.  Taurine deficiency will cause blindness and heart problems in cats.

The protein in dry food, which is often heavily plant-based, is not equal in quality to the protein in canned food, which is meat-based.  The protein in dry food, therefore, earns a lower biological value score.

Because plant proteins are cheaper than meat proteins, pet food companies will have a higher profit margin when using corn, wheat, soy, rice, etc.

Andy - 16 years ago as a kitten

Veterinary nutritionists and pet food company representatives will argue that they are smart enough to know *exactly* what is missing from a plant in terms of nutrient forms and amounts - nutrients that would otherwise be in a meat-based diet.  They will then claim that these missing elements are added to their diets to make it complete and balanced to sustain life in an obligate carnivore.

The problem with this way of thinking is that Man is simply not that smart and has made fatal errors in the past when trying to guess how to compensate for such a drastic deviation from nature.  Not all that long ago (1980s) cats were going blind and dying from heart problems due to Man's arrogance.  It was discovered in the late 1980s that cats are exquisitely sensitive to taurine deficiency and our cats were paying dearly for Man straying so far from nature in order to increase the profit margin of the pet food manufacturers. 

There are several situations that can lead to a diet being deficient in taurine but one of them is using a diet that relies heavily on plants (grains, etc.) as its source of protein.  Instead of lowering their profit margin and going back to nature by adding more meat to the diets, the pet food companies simple started supplementing their diets with synthetic taurine.

This may be all well and good for this particular problem, but how do we know that Man is not blindly going along unaware of other critical nutrients that are missing from a plant-based diet? 

Why is Man so arrogant that he thinks he can stray so far from what a cat is designed by nature to eat?

Also note that synthetic taurine is manufactured from a chemical reaction and all taurine (at least that I know of) comes out of China.

With regard to the overall protein amounts contained in dry versus canned food, do not be confused by the listing of the protein percentages on the packaging.  At first glance, it might appear that the dry food has a higher amount of protein than the canned food—but this is not true on a dry matter basis which considers the food minus the water.  Most canned foods, when figured on a dry matter basis, have more protein than dry food.  And remember, even if this was not the case, the percentage numbers do not tell the whole story. It is the protein’s biological value that is critical.

Let's ask ourselves the following question:  How many cats become ill or die from these species-inappropriate diets yet the patient's diet is never even questioned as a possible cause of the illness or death?  We cannot answer that question definitively but I have no doubt that the answer would be "many".

Do cats survive on these heavily (synthetically) supplemented plant-based diets?  Yes, many of them do.

Do cats thrive on these diets?  No, they do not.

Please pay special attention to the words *survive* versus *thrive* as there is a very big difference between the two states of health.

Robbie - hunting his dinner

Fresh vs Highly Processed with Synthetic Supplements

There are two basic ways to meet our nutrient needs:

1. Eat fresh food with a short ingredient list - or at least one that does not resemble a science experiment full of long names that are hard to pronounce.

2. Eat highly processed foods that have had much of their nutrient content destroyed or altered, with food chemists 'fixing' the deficit with synthetic supplements.  This type of unhealthy diet is consumed under the assumption that humans know exactly what was destroyed or altered during processing and what needs to be added back and in what form and amount.  Again, Man is simply not that smart.

While canned food is not 'fresh', per se, dry food undergoes a harsher processing.  It has been cooked at very high temperatures for a long period of time.  The extensive cooking required to remove most of the water from the food (70% moisture -> 5-10% moisture) significantly alters the biological value of the protein sources and damages other vital nutrients.

Humans then have to guess which nutrients – in what form and amounts – were destroyed by this cooking process and then try to add them back into the diet.  Occasionally 'real food' is used instead of synthetic supplements but those long and hard-to-pronounce names on the ingredient list describe chemically synthesized nutrients. 

Given that Man will never be as smart as nature – we will never know every detail of a cat’s normal prey - it is obvious that there is a risk when arrogance and greed cause humans to stray so far from a cat’s natural diet.

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We Are Feeding Cats Too Many Carbohydrates

In their natural setting, cats—whose unique biology makes them true carnivores--would not consume the high level of carbohydrates (grains, potatoes, peas, etc.) that are in the dry foods (and some canned foods) that we routinely feed them. You would never see a wild cat chasing down a herd of biscuits running across the plains of Africa or dehydrating her mouse and topping it off with corn meal souffle. 

In the wild, your cat would be eating a high protein, high-moisture, meat/organ-based diet, with a moderate level of fat and with only  approximately 1-2 percent of her diet consisting of carbohydrates. The average dry food contains 35-50 percent carbohydrate calories.  Some of the cheaper dry foods contain even higher levels. 

This is NOT the diet that Mother Nature intended for your cat to eat. 

Many canned foods, on the other hand, contain approximately less than 10 percent carbohydrates.

Please note that not all canned foods are suitably low in carbohydrates.  For instance, most of the Hill's Science Diet (over-the-counter) and the Hill's 'prescription diets' are very high in carbohydrates and are not foods that I would ever choose to feed.

Cats have a physiological decrease in the ability to utilize carbohydrates due to the lack of specific enzymatic pathways that are present in other mammals, and they lack a salivary enzyme called amylase.

Cats have no dietary need for carbohydrates and, more worrisome is the fact that a diet that is high in carbohydrates can be detrimental to their health as is explained below.

With this in mind, it is as illogical to feed a carnivore a steady diet of meat-flavored cereals as it would be to feed meat to a vegetarian like a horse or a cow, right?  So why are we continuing to feed our carnivores like herbivores? Why are we feeding such a species-inappropriate diet?  The answers are simple.  Grains/potatoes are cheap.  Dry food is convenient.  Affordability and convenience sells. 

However, is a carbohydrate-laden, plant-based, water-depleted dry food the best diet for our cats?  Absolutely not. 

Obligate carnivores are designed to eat meat/organs – not grains/vegetables - and they need to consume water with their food as explained below.

Cats Need Plenty of Water With Their Food

Toby - very lean, energetic and athletic on a proper diet.  He is 16 years old and still runs around like a kitten.

Learn How To Read a Pet Food Ingredient Label

Form more details regarding pet food ingredient labels, see Commercial Foods.

Before you get too confused and frustrated when reading this section, I will say at the outset:  I would much rather see a cat eat any canned food versus any dry food - regardless of quality level of the canned or dry food.  This includes Friskies, 9-Lives, Fancy Feast, etc., canned options.  I am so tired of seeing cats suffering tremendously from blocked urethras and other urinary tract diseases because of Man's love affair with dry food.

Try not to drive yourself nuts when picking out a canned cat food.  The fact that you are feeding canned food and not dry food is 90% of the battle so just do the best that you can - given the information below and on the Commercial Foods page.

That said, after becoming increasingly frustrated with the commercial pet food industry in 2003, I started making my cats' food.  See Making Cat Food for more information.

When reading this section, two words need to be firmly in your mind:

1. composition (the percentage of protein, fat, and carbohydrate in the food)

2. ingredients

Unfortunately, pet food labels are not held to the same standard as human food labels.  This means that pet food labels are seriously lacking in usable information when compared to a package of food for a human.

The "guaranteed analysis" numbers that you find on a can of food for protein, fat, and water (moisture) are listed as "minimums" and "maximums" which, by definition, are inaccurate.  Plus, the labels never list the carbohydrate amount which is very frustrating because we are trying to stay under 10% carbohydrate calories.

This makes it impossible to accurately evaluate the food in terms of composition.

See the Cat Food Composition chart for information on many cat food options.

The ingredient list can help us out - but only in some ways.  For instance, if you do *not* see high carbohydrate ingredients such as grains, potatoes, peas, etc., listed on the label, it is a safe bet that the food is low in carbohydrates.

However, if these high carbohydrate ingredients are listed, you have no idea of the amount in the food and, therefore, no knowledge of the carbohydrate level. 

Without knowing the actual amount of each ingredient, we have no indication of the impact of the ingredient on the nutritional profile of the food.  Only the composition value will answer that question. This is why it is important to not just consider the list of ingredients but to also look at the protein/fat/carbohydrate profile of the food.

A good example of the above issue is a food like canned Wellness. At first glance, this food may be dismissed as inappropriate for a carnivore because it contains several high carbohydrate ingredients in the form of fruits and vegetables, including potatoes which are very high in starch (carbohydrate). However, the low carbohydrate level (3-5%) tells us that the amount of fruits and vegetables is very low. 

Grains and potatoes should be absent from a cat's diet but, unfortunately, they are cheap so they are included in many commercial cat foods. Think 'profit margin'. Grains/potatoes are cheaper than meat.

Stay away from food with gravy and sauces because they usually use high carbohydrate thickeners.

Soy contains phytoestrogens and soy also negatively influences the thyroid gland. Given how common hyperthyroidism is in the cat, soy has no business being in cat food. Unfortunately, soy is a common ingredient used by many pet food manufacturers - especially Purina - because it enhances their profit margin.

When considering allergies, the ingredient list is useful since we don't care how much of the offending ingredient is in the food.  The bottom line is that we don't want any of the ingredient to be present.  Fish/seafood, beef, lamb, corn, wheat, and soy tend to be the most hyperallergenic ingredients for the cat - especially fish/seafood.

By-products are always a controversial subject but it makes much more sense to feed animal-based by-products to a cat than it does to feed grains or potatoes.  Therefore, do not shy away from the more economical foods like Friskies or 9-Lives if you cannot afford the more expensive canned foods without by-products.

I would much rather see a cat eating an all-by-product canned food than any dry food.  This is because even the cheaper canned foods have the 'Big Three' covered:

1) high in water

2) usually low in carbohydrates

3) the protein is from animals - not plants

By-products are not necessarily low quality protein sources. In fact, they can be extremely nutritious. However, there is more variability when quality is being considered when compared to muscle meat. 

By-products are discussed in more detail on the Commercial Foods page in this section.

The higher priced canned foods that I referenced above, have a muscle meat listed as the first ingredient. A muscle meat will be listed as “chicken,” or “turkey,” etc., not “chicken by-products” or “chicken by-product meal,” or “chicken broth” or "liver". “Chicken meal” is technically a muscle meat but the term “meal” denotes that it has been rendered (cooked for a long time at very high temperatures) and is lower in quality than meat that has not been as heavily processed. A "meal" product is more commonly found in dry foods. By-products can include feet, intestines, feathers, egg shells, etc., which are less nutritious (less biologically valuable/digestible) than meat.

Avoid foods listing "liver" as a first ingredient.  (Example: Purina's prescription diet DM canned for feline diabetic patients.  There are far better options available that are healthier and not as expensive.) 

Liver is a very nutritious organ meat - and should be present in small amounts - but it should never be the first ingredient as it is very high in vitamin A and possibly D and you don't want to feed too much of those vitamins. Liver is cheaper than muscle meat so it will increase a company's profit margin when used in high amounts.

Preservatives are important ingredients that we need to pay attention to.  BHA, BHT, and ethoxyquin are extremely questionable in terms of safety.  Please note that Hill’s has always used BHT, and ethoxyquin in many of their products although recently I have noticed that these chemicals have been removed from some of their foods.  Be sure to check the current labels.  Other companies abandoned the practice of using these chemicals as preservatives long ago – opting for more natural and safer methods.

Also, please take note of a recent deceptive move by Hill's whereby they have incorporated into their labeling the word "maize" as a substitute for the word "corn".  Maize IS corn and since this company is well aware of the fact that consumers are becoming more savvy about pet food ingredients, they have decided to try to disguise the corn in their diets by calling it "maize".  Hill's is hoping that consumers stay ignorant regarding the fact that maize is corn.

I do not use products made by Hill's (including their over-the-counter and "Prescription Diets") since there are always better options available.

Willie

 Marketing Labels

Marketing labels such as "natural", or "premium", or "veterinarian recommended" are not necessarily indicative of high quality so please be careful not to fall into that trap.

"Indoor only" is another meaningless marketing  label that is nothing more than an enticing gimmick. This label originally started out in the dry food market but it has now made its way to canned food labels.  Cats did not stop being obligate carnivores just because we put a roof over their heads.

If you are thinking about feeding any 'breed-specific' food, please see this link for some straight-forward comments about the utterly absurd claims that these companies make regarding these diets. A Siamese is no different from Persian or a Maine Coon - or an 'alley cat' - when considering optimal dietary composition. No matter the breed, the cat is still an obligate carnivore.

Royal Canin was one of the first companies to come out with these breed specific diets as a marketing gimmick.

The labels on Hill's over-the-counter products contain a statement that says "Veterinarian Recommended".

Unfortunately, many of my colleagues do, indeed, recommend products made by Hill’s (as well as Purina, Iams, and Royal Canin) and this is a testament to the fact that most veterinarians are not well-versed in proper feline nutrition and simply defer to these large companies that have huge marketing budgets.  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.

Keep in mind that a large marketing budget does not equate with the manufacturing of high quality or healthy products. 

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'Prescription/Therapeutic' Diets

Let's move on to the veterinarian 'prescribed' diets which are also known as "therapeutic" or "prescription" diets. 

"Prescription/therapeutic diet" is another label that is certainly not indicative of a high quality diet or one that is necessary. 

These diets represent an area of the commercial cat food industry that is very misleading.

Many of these very expensive products contain corn, wheat, and soy which have no logical place in your cat's diet.  These diets are often very high in carbohydrates and, of course, all of the dry versions are water-depleted.  Many of them also contain by-products as the main - and often only - source of protein. 

While by-products can be very nutritious (and this really is the least of my concerns regarding these diets), they are cheaper than muscle meat so one would think that as much as these diets cost, the companies could use a more consistent source of high quality protein.  (See by-products on the Commercial Food page for more details.)

Study the ingredient list for Hill's dry i/d while keeping in mind that cats are obligate carnivores.

This dry food is 29% carbohydrates on a dry matter basis and is, of course, water-depleted.  The ingredients are as follows:

Chicken By-Product Meal, Brewers Rice, Corn Gluten Meal, Whole Grain Corn, Pork Fat (preserved with mixed tocopherols and citric acid), Powdered Cellulose, Dried Chicken, Chicken Liver Flavor

The base ingredients and composition mirror those of many dry foods found in pet stores and supermarkets.  Also, this is a very good example of the 'ingredient splitting' rule.  This rule states that ingredients have to be listed very specifically which works in the pet food manufacturers' favor.  It allows the grain fractions to be broken up into smaller components which places them lower on the list since ingredients are listed by weight.  However, when all of the grain fractions are added up, their contribution to the diet (including the protein content) often greatly outweighs the first ingredient.

I have asked many times on VIN (Veterinary Information Network - the 'who's who' of veterinary specialists from all over the world) just what makes this diet worthy of being called a "Prescription Diet for Feline Gastrointestinal Health" or, for that matter, what makes it an optimal diet to feed to any cat? I have never received an answer and the VIN threads have had Hill's representatives participating.  My questions about the quality and composition of their prescription diets are always met with dead silence.

It is important to note that most of these diets do not have robust clinical feeding studies supporting their safety for long-term feeding or even for use in treating the various diseases they target.

On the contrary, we have plenty of evidence to show that feeding water-depleted, high carbohydrate, plant-based diets to carnivores does not honor their carnivorous make-up but, instead, promotes disease in this species.

It is also critical to understand that there is no independent agency overseeing these diets' medical claims.  None. Zero.  Including the FDA. 

The fox is definitely guarding the henhouse and the FDA shows no interest in remedying the situation.

The FDA has 'punted' the responsibility of scrutinizing these diets for efficacy, safety, and suitability to the veterinarian but most veterinarians are very poorly educated in the area of nutrition. This field of study is not emphasized in veterinary schools and the minimal course work that is required, is often taught by people who have strong ties to the pet food industry.

These are also usually the same people who are advising general practitioners on all matters of nutrition.  After recognizing this situation, you will see an obvious and very significant conflict of interest.  In the end, the members of my profession allow Hill's, Purina, Iams, and Royal Canin to dictate what ends up in our patients' food bowls.

Here is an excerpt from the "Veterinarian-Prescribed Diets/OTC Options" paper that I am working on:

'Prescription Diet’ trademark - marketing tool creates false perception

As an example of the serious lack of regulatory oversight, Hill’s secured trademark status for the term “prescription diet” in 1990 thus reinforcing the perception that, like prescription medications, their diets are subject to intense scrutiny and testing.  However, nothing could be further from the truth.              

There is a strong argument to be made that no trademark protection should be granted for any marketing label containing the word “prescription” given the strong potential to seduce the buyers of these products into a false sense of security growing out of the assumption that anything  labeled “prescription” has been put through multiple layers of regulatory and testing paces.                

If any product - including food - is allowed to carry a “prescription” label, it needs to be held to the same standards as a prescription medication.  Otherwise, the word “prescription” becomes no more than a marketing label, and as such, should hold no more credibility than any other marketing slogan.

To quote the FDA/CVM Communications Staff Deputy Director:              

“‘Prescription diet’ is an industry-coined term and holds no legal meaning.”              

In other words, these diets contain no ingredient that actually requires a prescription.  The trademarked term “prescription diet” is simply a clever marketing tool between Hill’s and veterinarians.  The sale of these diets is restricted (by Hill’s, not by law) to veterinarians only.  In return, Hill’s enjoys a boost in perception of quality brought about by this profession’s endorsement of their products.  However, this perception of quality is undeserved and this incestuous relationship jeopardizes the integrity of our profession.

End excerpt

I want to make it clear that probably 99% of all veterinarians who 'prescribe' these diets truly feel that they are doing the best for their patients.  The companies (Hill's, Purina, Iams, Royal Canin) that manufacture the 'alphabet' diets have done a wonderful job marketing their products to veterinarians, making it difficult to refrain from falling into the trap of using them.

These companies make it very easy for us.  If a cat comes in with kidney disease?  We can just grab k/d, or NF, or LP without any critical thought.  If a cat comes in with a urinary tract problem?  Easy - take some c/d off the shelf.  Given a veterinarian's busy schedule and stressful life, one can see just how seductive the use of the 'alphabet' diets are.

However, contrary to what is often believed by both the veterinarian and the client, the 'therapeutic/prescription' diets sold in veterinary hospitals are not formulated for optimal health of a carnivore and, in many cases, are actually detrimental to the patient's health.  In addition, they are simply not necessary in most cases and do not optimally address the problems they claim to treat.

Add to this the very high price tag on these diets and we have what I consider to be a very big 'black eye' for the profession. 

The only time I ever use a prescription diet (canned s/d) is discussed here on the Urinary Tract Health page. Canned s/d is occasionally used but only temporarily (~3-4 weeks) pending re-evaluation of the patient.

Instead of defaulting to the 'alphabet' diets, I can always find an 'over-the-counter' diet or formulate a homemade recipe for my patients that leaves more money in the client's wallet and much better nutrition in the cat's food bowl.

Regarding making cat food:  People often overestimate what it takes to make a nutritious meal for their cat and assume that it means slaving away in the kitchen every day.  I can assure you, it is much easier than that. For the past 10 years, I have spent a few hours in the kitchen 4-6 times a year making food for my cats which is a very small price to pay for the control that I have over what goes into their food bowls.  I do not feed any commercial cat food.

I would love to see veterinarians stop being so 'married' to the diets they reach for every day and learn the basics of optimal feline nutrition and start considering the use of higher quality, lower cost, over-the-counter - or homemade - diets.  Their patients - and their clients' bank account - will be a lot better off for it.

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Andrew

Common Feline Health Problems and Their Ties to Diet

There is a very strong and extremely logical connection between the way that we are currently feeding our obligate carnivores and many of the life-threatening diseases that afflict them.

• Diabetes:  Diabetes is a very serious – and difficult to manage – disease that is not uncommon in cats.  We do  not know all of the causes of this complex disease but what we do know is that many diabetic cats cease needing insulin or have their insulin needs significantly decrease once their dietary carbohydrate level is decreased to a more species-appropriate level than that found in many commercial foods.

Given this fact, and given what we know about how the cat processes carbohydrates, it is not a stretch to say that high carbohydrate diets could very well be a significant factor in causing diabetes in some cats.

Please see this paper discussing the elevated blood glucose in cats after eating a high carbohydrate meal:

Postprandial glycemia

There are countless cases of successful diabetic remission when cat caregivers remove all dry food and all high carbohydrate canned food from their cat's diet.

In addition to the issue of carbohydrates and how they affect the blood sugar level of some cats, dry food is very calorie dense, is very palatable, and is usually free-fed. This often leads to obesity.

Fat cells produce a substance that makes the other cells in the body resistant to insulin.  This promotes the diabetic state. 

It is very important to understand the impact that a low carbohydrate diet has on the insulin needs of a diabetic cat.

If you have decided to start feeding your diabetic cat a low carbohydrate diet, please do not change the diet until you review my Feline Diabetes page - especially the STOP sign section - otherwise you will be putting your cat in danger.

Please also be aware that many veterinarians underestimate the favorable impact that a low carbohydrate diet has on the insulin needs of the patient and they do not lower the insulin dose enough.  If the insulin is not lowered accordingly, an overdose of insulin will occur which can be life-threatening. 

I strongly suggest that all caretakers of diabetic cats home-test to monitor blood glucose levels using a standard glucometer as a matter of routine.  Careful monitoring is especially important when implementing a diet change.

Many veterinarians prescribe expensive diets such as Purina DM (Diabetes Management) and Hill's m/d but you can do much better for your cat (and your pocketbook) by feeding other more nutritious - and lower carbohydrate - canned foods such as Merrick, Wellness, Nature's Variety, EVO, etc.  See the Cat Food Composition chart.  You should aim for a diet that derives less than 10% of its calories from carbohydrates.

The less expensive foods like Friskies, 9-Lives, and Fancy Feast are also fine to feed.

• Kidney Disease (CKD - formerly called "CRF"):  Chronic kidney disease is probably the leading cause of mortality in the cat.  It is troubling to think about the role that chronic dehydration may play in causing or exacerbating feline kidney disease.  And remember, cats are chronically dehydrated - especially CKD cats - when they are on a diet of predominantly dry food.  The prescription dry 'renal diets' such as Hill's k/d - which are commonly prescribed by veterinarians - contain only a small amount of moisture (~10% versus 78% for canned food) leaving your cat in a less than optimal state of water balance.

I must say that I find it truly amazing when I hear about the very large numbers of cats receiving subcutaneous fluids while being maintained on a diet of dry food.  This is an extremely illogical and unhealthy practice and every attempt should be made to get these cats on a diet that contains a higher moisture content. 

Please also note the following list of the first four ingredients of Hill's dry k/d after reviewing this section on reading a pet food label - and bearing in mind that your cat is a carnivore. 

This is a diet that would never find its way into a food bowl owned by any cat in my care. 

The first three ingredients are not even a source of meat and the fourth ingredient is a by-product meal which is not necessarily an unhealthy source of protein but it would be nice to see some muscle meat ("chicken") in this product.

Brewers rice, corn gluten meal, pork fat (preserved with mixed tocopherols and citric acid), chicken by-product meal

The purpose of this 'prescription' diet is to restrict protein which, unfortunately, it certainly does.  However, please understand that there are no studies showing that restricting protein to this level will prevent further deterioration of kidney function. 

k/d restricts protein to the point that some cats - those that are not consuming enough of the diet to provide their daily protein calorie needs - will catabolize (use for fuel) their own muscle mass which results in muscle wasting and weight loss.  This internal breakdown of the cat’s own muscle mass will cause an increase in creatinine (and BUN) which needs to be cleared by the kidneys. The rise in creatinine and BUN, and muscle wasting, can lead to an often-erroneous conclusion that the patient’s CKD is worsening. 

Of course, the same deterioration can occur in any cat that is not consuming enough protein, but the level of protein in this diet is not only at an extremely low level, it is in an incomplete form for a carnivore.  Note that it is made up mainly of plant proteins - not meat proteins.  It is also water-depleted as is the very definition of all dry foods.

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• Cystitis (bladder inflammation), Urethral Blockage, Bladder/Kidney Stones:

Please see Feline Urinary Tract Health for a more detailed discussion. The first paragraph on that webpage states:

If I could have the reader 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.

Cystitis is an extremely common and very painful problem in the cat. Stones are also very common and can lead to a life-threatening urinary tract blockage.

I sincerely hope that these pictures of Opie make a huge impact on anyone who is still not convinced that dry food causes significant suffering in many cats.  Rest assured that veterinarians deal with blocked cats extremely frequently which is heartbreaking considering how rarely cats block when on all canned food - especially with added water.

Cystitis can lead to inappropriate urination (urinating outside of the litter box) and stones can cause a fatal rupture of the bladder by blocking the outflow of urine. 

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.

It is important to note, however, that "crystals" are not the same thing as stones.  Crystals are often a normal finding in a cat's urine and it is not necessarily appropriate to put the cat on a "special urinary tract" formula when these are found in the urine.

Important: I often see too much clinical significance placed on the identification of crystals in the urine without regard to how the urine sample was handled.  It is very important to understand that crystals will often form once outside of the body within a very short (30-60 minutes) period of time. 

If the veterinarian does not examine the urine right away and either sends it to an outside laboratory or uses a free-catch sample that the owner brought from home, an erroneous diagnosis of crystals may be made.  This is called a "false positive" report and results in unnecessary worry on the part of the owner and often leads to the cat being placed on an inappropriate, low quality diet.

With regard to overall kidney and bladder health, I cannot stress strongly enough how important water is in both the prevention and treatment of diseases involving this organ system. 

When a cat is on a diet of water-depleted dry food, they produce a more highly concentrated urine (higher urine specific gravity - USG) and they produce a lower volume of urine (often half of what a cat on canned food produces) which means that a higher concentration of crystals will be present in the urine.  This increases the chance of these crystals forming life-threatening stones.  It is also thought that the highly concentrated urine may be very irritating to the bladder wall in some cats, predisposing them to painful cystitis.

Please keep in mind that a cat has a very low thirst drive and is designed to get water with their food.  A diet of canned food will keep a proper amount of water flowing through the urinary tract system and help maintain its health.

Adding 1-2 TBS of water (plain or flavored – such as tuna water, clam juice, chicken or beef broth) per meal is also very beneficial.  Make your own tuna water by taking one can of tuna and mixing the contents into 3 cups of water.  Mash it up and let it sit for ~15 minutes.  Pour the water into covered ice cube trays.  Freeze to prolong the freshness.  Use covered trays to keep the water tasting and smelling fresh.

Water fountains may also help cats consume more water but feeding a water-rich diet is much more effective in increasing your cat's water intake than water fountains or multiple bowls of water sitting around your house. 

If you are still worrying about small amounts of crystals in your cat's urine, consider this analogy:

Crystals in cat urine are as normal as the leaves that fall on your driveway.  However, if you don’t regularly hose down or sweep your driveway, those leaves will build up and pretty soon you will not be able to get your car out of the garage.

This is what happened to Opie above.  His 'driveway' (urethra) got blocked and he was unable to pass any urine resulting in a tremendous amount of suffering and a life threatening situation.

If you picture crystals as the leaves in this analogy, it is easy to see how canned food does a better job of flushing out your cat’s bladder - several times each day - than dry food does.

To repeat, crystals are not an abnormal finding in cat urine. However, they can become a problem if Man continues to insist on feeding the cat a water-depleted diet.

Mindy and Mikie

Urine pH is also often considered when discussing urinary tract problems but we really need to stop focusing so heavily on pH. Again, a proper amount of water in the diet is the important issue here - not urine pH.

Many of the often-prescribed feline lower urinary tract diets are formulated to make the urine acidic but it is thought that these low magnesium, acidifying diets may actually exacerbate painful cystitis. Also, these acidifying diets often end up promoting calcium oxylate stone formation and can also lead to hypokalemia (low potassium in the blood) which can cause or exacerbate kidney disease.

It is also important to note - for those people still stuck on worrying about the urine pH - that there are many factors which determine the pH of urine and only one of them is diet.

Urine pH varies throughout the day and using one pH measurement from a single urine sample is very misleading and is not terribly helpful information. 

With regard to dry food and urinary tract health, aside from the lack of water in this type of diet, there is also a correlation between the consumption of a high carbohydrate diet and the formation of struvite crystals as shown by this study because carbohydrate diets promote an alkaline urine.

Veterinarians often prescribe Hill's Prescription dry c/d for urinary tract problems but again, these diets are only ten percent water and contain a high level of species-inappropriate ingredients and questionable preservatives.  They are also very high in carbohydrates with dry c/d containing 42 percent of its dry weight as carbohydrates. 

Please note the first few ingredients in c/d while remembering that your cat is a carnivore:

Previous formulation:

Brewers rice, chicken by-product meal, corn gluten meal, pork fat (preserved with mixed tocopherols and citric acid),chicken liver flavor, taurine, preserved with BHT and BHA

Newer formulation:

Brewers rice, corn gluten meal, chicken by-product meal, pork fat (preserved with mixed tocopherols and citric acid), chicken, chicken liver flavor, fish oil,

Note that Hill's removed the BHA and BHT but are now using more corn gluten meal and less chicken by-product meal.

Diet is not the only issue involved with cystitis but it is an important one and one that we can control.  Stress is also thought to play a very significant role in cystitis and even cats that are fed a 100 percent canned food diet may experience bouts of cystitis. 

This is a very frustrating disease to deal with and one that the veterinary community does not have all the answers for.  What we do know is that decreasing stress and increasing the water content of the diet are the most important management issues to address.  The water content of the diet is easy to control - feed canned food with added water.  The stress issue is another matter and is not always easy to address since cats can be very sensitive and are often 'silent' in their stress.

Cystitis can be extremely painful and it is very important to address pain management in these cats.  Remember:  pain = stress and we are trying to minimize the stress in these patients. 

Buprenex is a good choice for a pain medication and I often dispense it for the client to have on hand for chronic cystitis patients - as long as the client understand the critical importance of close monitoring of the patient to make sure he is passing urine and is not obstructed.  (I say "he" because males have a long, narrow urethra and are much more apt to block than females.)

Buprenex is superior to Torbugesic which has been used for pain management in the cat in the past.  (Burprenex is a prescription medication that you must get from your veterinarian.)

Unfortunately, many veterinarians overlook pain medications as a very important part of the treatment of this common feline problem.

Andy

A very important note on antibiotic usage in these cases:  Most cases of cystitis are sterile.  In other words, they are not the result of an infection and the patient should not be placed on antibiotics.

Only ~1% of cats with cystitis that are under 10 years of age have a urinary tract infection, yet many veterinarians place these patients on antibiotics when these drugs are not warranted.  Most cats under 10 years of age produce a very concentrated urine (USG greater than 1.035) and bacteria do not grow well in concentrated urine.

In cats over 10 years of age, infections are more common but that still does not mean that older cats with cystitis should automatically be put on antibiotics.  The reason that an older cat is more prone to urinary tract infections is because kidney disease is more common in this age group and so these cats will have a more dilute urine which is not as hostile to bacterial growth.

Diabetes and hyperthyroidism are also more common in cats over 10 years of age and both disease render the patient more prone to urinary tract infections.

That said, only ~20% - or less - of all older cats that present with lower urinary tract signs (see Feline Urinary Tract Health - Cystitis) actually have an infection so ~80% of this age group exhibiting these clinical signs do not need to be put on antibiotics.

A urine culture and sensitivity (C & S) should be run to check for an infection, especially if the patient has a low urine specific gravity or is diabetic.  It must be kept in mind that even with a low USG, most cases of cystitis are not due to an infection.  This is why it is important to run a C & S before placing the patient on antibiotics.

Antibiotics are NOT harmless drugs and they need to be used with more critical thought than is currently happening in both human and veterinary medicine.

A C & S test identifies the bacteria (if present) and tells the veterinarian which antibiotic is appropriate.  The urine for a C & S needs to be obtained by way of cystocentesis which involves using a syringe and needle to obtain urine directly from the bladder. 

This is not a painful procedure for the cat and this method is the only way to obtain a sample for accurate information in order to properly treat with antibiotics.  One problem, however, is that a sample may be difficult to obtain without waiting a couple of hours since cats with cystitis urinate frequently and often do not have enough urine in their bladder to get a good sample.

To get around this problem, some veterinarians will give the patient a dose of subcutaneous (just under the skin) fluids.  The cat is then put into a cage without a litter box.  Within a couple of hours (or less), the bladder is usually full enough to obtain a urine sample via cystocentesis.

We have to stop treating all cases of cystitis with antibiotics without supporting evidence of an infection!

Cystitis will often recur in these patients and this painful health problem can be very frustrating to deal with.  On a good note, most cats will have their clinical signs spontaneously resolve even without any treatment.  In fact, it has often been said, jokingly, that a cat with cystitis will often stop exhibiting clinical signs within seven days with antibiotics and in one week without antibiotics.

Unfortunately, when people don’t understand this issue, antibiotics often get the credit when they had nothing to do with the patient’s improvement. When this happens, the abuse of antibiotics continues.

• Inflammatory Bowel Disease (IBD): IBD can cause vomiting, diarrhea, and/or constipation in the cat.  IBD can also present with weight loss as the only clinical sign.   There are many unanswered questions with respect to this disease process, but it is logical to start to “treat” a gastrointestinal problem in the cat with a species-appropriate diet considering that it is food that 'bathes' the problem area.

Too often these cats are treated with a high level of steroids and a prescription grain-laden dry food diet.  I feel very strongly that this common therapeutic regimen dismisses the very significant role that a proper diet plays in our IBD patients.  There are an impressive number of anecdotal reports of cats that were terribly ill with IBD that exhibit dramatic improvement when all dry food was removed from their diet and a grain-free/low-carb canned food was fed instead.

Taking it even one step further, there are many reports of cats with IBD that improved tremendously on a balanced, grain-free, homemade diet. (See Making Cat Food for a balanced recipe.)

Some cats do need steroids (temporary or long-term) but we need to focus more heavily on feeding these patients an appropriate diet rather than simply relying on immunosuppressive medications.

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  Robbie had severe diarrhea for two years until put on a grain-free, vegetable-free, homemade diet.

• Hairballs: The frequent vomiting of hairballs can be a symptom of IBD.  "Frequent" is hard to define, in this case, but if your cat is vomiting hairballs on a weekly basis do not just assume that this is simply normal feline behavior.

I often receive emails asking what the best diet is to feed to cats suffering from hairballs.  The bottom line is that as much hair as possible should be prevented from getting into the cat in the first place.  This is accomplished with daily brushing or, in some cases, shaving the cat if hairballs are creating serious problems.

Amber loves going naked in the summertime

I understand that shaving cats is not an easy task and is, therefore, not a 'quick fix' for this problem but it is an option for serious cases.

Amber can only be shaved when she is under general anesthesia.  Therefore, almost every summer she gets a dental cleaning and body shave to keep her comfortable during the hot summer months.  She never had a problem with hairballs even with a full coat but she is a lot happier without her long hair when the weather is hot.

Hairball problems are not just associated with long hair coats.  Shorthaired cats - especially double-coated cats - can also have problems with hairballs. However, a healthy intestinal tract should be able to deal with hair normally ingested by the cat.

That said, if we want to help our cats out in this area, we need to brush them daily.

Trying to 'chase' hair after it has gained entrance into the cat's intestinal tract is futile.  Diet is not the answer and neither are any of the 'hairball remedies' on the market.  As one well-respected feline medicine specialist often states "this is not a grease deficiency!"

• Obesity:  Obesity is an extremely common and very serious health problem in cats.  Overweight cats are four times more likely to develop diabetes than cats that are at an optimal weight.

Bennie before being rescued

Obese cats cannot clean themselves properly resulting in painful skin inflammation in their perineal area

Just after I broke Bennie out of jail

Obese cats suffer from painful orthopedic problems

Mindy and Molly - just after Molly discovered how good canned food is for her obese but carnivorous body

Obligate carnivores are designed to meet their energy needs with a high protein, moderate fat diet with little to no carbohydrates. Carbohydrates are minimally used for energy and those that are not used are converted to and stored as fat.  The so-called “light” diets that are on the market have targeted the fat content as the nutrient to be decreased.  The choice is then to raise either the protein or carbohydrate content of the diet, or both.

Since animal-based protein (meat and organs) is more expensive than carbohydrates (grains/potatoes/peas), pet food manufacturers raise the carbohydrate levels in these foods making them very species-inappropriate and unhealthy.

An optimal weight loss diet should be:

• high in protein (over 40% of calories),

• moderate in fat (under 50% of calories),

• low in carbohydrates (under 10% of calories), and

• high in water.

When looking at the Cat Food Composition chart, you will note that there are not many examples of this profile.  Why?  Because fat is cheaper than protein.  The calories from protein + fat + carbs must = 100%.  If the carbs are kept below 10%, that leaves 90-95% of the calories to be divided between protein and fat.

Protein is expensive.  Fat is cheap.  Therefore, low carb diets are usually high in fat.

Examples of nice profiles include, Merrick, Friskies Classic Pates, Tiki Puka Puka Luau, and Tiki Koolina Luau.

You will notice that many of the higher protein diets are fish-based but it is not a good idea to feed fish to cats.  Or, at least not as their main diet.  Fish can be high in mercury, high in PBDEs (fire retardant chemicals linked to hyperthyroidism), high in phosphorus (not good for older cats' kidneys) and can be very addicting.  It is best to feed poultry-based diets to cats.   

Water content of the diet is very important.  Studies have shown that cats lose weight much easier on canned food versus dry.  Dry food is very calorically dense and is high in carbohydrates which are not as satisfying to a cat as protein is.

Many cats on the commercial 'light' or 'less active' diets either do not lose weight or do lose weight but also lose muscle mass along with the loss of fat. This is not our goal. The goal is to lose fat while maintaining muscle mass.

In several studies, cats fed a high protein/low carbohydrate diet lost weight but maintained their lean body mass in comparison to cats fed a high carbohydrate/low fat diet.

Many caretakers feed very small amounts of these "light" diets hoping that their cat will lose weight.  However, feeding a small amount of a diet that is inappropriate for the species is not the answer! The caretaker often ends up with either a crabby, overweight cat or a thinner cat that may have lost too much muscle mass.

See Molly’s and Bennie’s story of weight loss on this site's Feline Obesity page to read about how these sweet cats went from inactive obese cats that could barely walk or clean themselves to healthier, happier felines.

Molly had great difficulty walking and cleaning herself due to her obese condition which was brought on by the consumption of dry food.  Kittens, however, loved using her for a pillow. 

Molly’s veterinarian had prescribed Hill's Prescription dry r/d for her and instructed her caretaker to feed Molly only very small portions - and to put a shock collar on her to keep her away from her housemates' food.  This is obviously not sound - or humane - obesity management advice.  Hill's Prescription r/d is a poor quality, high carbohydrate (35%) diet that contains the following inappropriate and unhealthy ingredients including a high level of fiber which a feline intestinal tract is not designed to process:

Previous formulation:   

Chicken by-product meal, corn meal, powdered cellulose 18.5% (a source of fiber),corn gluten meal, chicken liver flavor, vegetable oil, taurine, L-carnitine, preserved with BHT, BHA and ethoxyquin

Current formulation:

Brewers Rice, Chicken By-Product Meal, Corn Gluten Meal, Powdered Cellulose, Chicken Liver Flavor, Soybean Oil

Note that Hill's removed the BHA and BHT but a plant-based protein is now the predominant protein source instead of an animal-based protein. This diet is even more unhealthy than it used to be.

There are much more species appropriate - and less expensive - ways to address feline obesity.  However, if you are contemplating the use of the grain-free, high protein/low carb dry foods, please understand that these diets are very calorie-dense and often lead to  weight gain, in addition to being detrimental to urinary tract health because of their water-depletion.

• Dental Disease:  Long-standing claims that cats have less dental disease when they are fed dry food versus canned food are grossly overrated, inaccurate, and are not supported by recent studies.  This frequently stated (among veterinarians and lay people) myth continues to harm cats by perpetuating the idea that their food bowls need to be filled up with an unhealthy diet in order to keep their teeth clean. 

The idea that dry food promotes dental health makes about as much sense as the idea that crunchy cookies would promote dental health in a human.

First, dry food is hard, but brittle, and merely shatters with little to no abrasive effect on the teeth.  Second, a cat's jaws and teeth are designed for shearing and tearing meat - not biting down on dry kibble.  Third, many cats swallow the majority of their dry food whole.

There are many factors – known and unknown - that contribute to dental disease in the cat such as genetics, viruses, diet,  and the fact that cats do not brush their teeth like humans do. There remain many unanswered questions concerning the fact that cats often suffer from poor dental health but one very obvious answer lies in the fact that Man feeds the cat a diet that does not even come close to what they would eat in their natural state.

When cats consume their prey in the wild, they are tearing at flesh, hide, bones, tendons, and ligaments. This is a far cry from the consistency of dry or canned food.

Neither dry kibble nor canned food comes close to mimicking a cat’s normal diet of mice, birds, rabbits, etc. Given what a cat does eat in nature, it makes much more sense to be feeding part of the diet in the form of large chunks of meat (as large as you can get your cat to chew on) or gizzards (tough and fibrous) which a cat’s teeth are designed to chew. Raw meat is ‘tougher’ to chew than cooked meat so I prefer to use raw meat – or lightly baked to kill the surface bacteria - to promote dental health. See Making Cat Food - Dental Health.

Notice the phrase “part of the diet” in the above sentence.  It is very important to understand that plain meat (ie - without bones or another source of calcium) is very unbalanced since there is minimal calcium in meat.  Remember that when a cat eats his normal prey, he is consuming the bones along with the meat.

When fed as a supplement to most commercial canned foods, it is safe to feed ~15 - 20% of the daily calories in the form of plain meat.  For example, if a cat is eating 6 ounces of canned food per day, you could feed him 5 ounces of canned food plus 1 ounce of chunked muscle meat per day.

When people ask me “how often should my cats be fed chunks of meat?”, I reply “how often do you brush your own teeth?” 

And speaking of brushing teeth, this is, by far, the best way to promote your cat's dental health.  See this video for more information.

Please pay close attention to the statement in the video regarding a thorough dental exam by your veterinarian before starting a brushing program.  

Many cats have very painful mouths but show no outward signs of this pain.  If you try to brush your cat's teeth in the face of a painful mouth, you will end up with a cat that is scared - along with developing a strong aversion to toothbrushes.  If this aversion occurs, you may never get him to accept tooth brushing once you have addressed the painful mouth with your vet.

With regard to frequency, once-daily is optimal.  By the time 72 hours have passed, the film on the teeth becomes permanent so shoot for at least every other day.

Please understand that I am not saying that canned food is necessarily better for teeth than dry food.  For optimal dental health, a cat should not be eating either canned or dry food since neither food type promotes a healthy oral cavity but we have to work with what is practical in a typical home setting and feeding a cat a 'whole carcass prey' diet is not terribly practical - even if it would be great for their teeth. 

The compromise is to at least give them some muscle meat to chew on, in addition to brushing their teeth if possible, and to stop fooling ourselves into thinking that dry food promotes dental health in our cats.

I am often asked about 'dental' diets such as Hill's t/d but if someone has read to this point on this webpage, it will be understood that these diets represent the epitome of 'tunnel vision' nutrition.  All 'dental' diets are all dry (water-depleted), all are all high in carbohydrates, and all contain species-inappropriate ingredients, and as such, even if they do impart any measurable effect on dental health, they wreak havoc on the rest of the body.

It is wise to feed for the health of the *whole* cat, not just one part of him.

Hill's t/d (34% carbohydrates):

Chicken By-Product Meal, Brewers Rice, Corn Gluten Meal, Powdered Cellulose, Whole Grain Corn, Pork Fat (preserved with mixed tocopherols and citric acid), Chicken Liver Flavor

Saint Molly never met a kitten she didn't treat as her own

• Feline Asthma/Allergic Airway Disease:  Many cats have had their respiratory symptoms (coughing/difficulty breathing) subside considerably, or disappear completely, once they were placed on a grain-free canned food diet, or a meat-based homemade diet.  Some of these struggling cats may have been reacting to storage mites or cockroach antigens that are present in dry foods, or they may have been reacting to the gluten (protein fraction) part of the grains that are present in dry foods. 

Sadly, many cats exhibiting debilitating lung disease are simply put on an immunosuppressive dose of steroids - while still being fed an inappropriate diet.  While steroids are necessary in many cases of airway disease, they are not addressing the root of the problem which can, in many cases, be an allergy to proteins in the form of species-inappropriate grains, and insect antigens. 

Steroids can cause diabetes in cats and also render them vulnerable to infections from viruses, bacteria, and fungal agents so it is very important to make sure you have ruled out diet as a cause of the cat's respiratory symptoms.

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This is the hard part. Cats, like children, often resist what is best for them.  The two most frequent comments that I hear from people when trying to convince them to feed their cats a healthier diet are "my cat won't eat canned food" and "but my cat really likes his dry food."   Children really like potato chips and ice cream but that certainly does not mean those food items constitute optimal nutrition.

The transition process often involves much more than just plunking down a new food item.  Time, patience and tricks are often required.

One reason that cats like dry food so much is because the pet food companies do not play fair when manufacturing this sub-optimal food source.  They coat the kibble with extremely enticing animal digest sprays which are very pleasing to a cat - making a poor quality diet very desirable to the target animal.

In addition to the aforementioned coating of dry food with animal digests, another issue  is one of a crunchy texture which is very different from canned food.  Cats are very resistant to such a drastic change in the texture of their food.

If you are convinced that getting your cat off of dry food is the way to go, read on for some tips on how to accomplish this.

The key is to do it slowly and with patience and incorporate various tricks for the stubborn cats. The most important issue is actually making the change, not how fast you accomplish it.   

I must say that my cats tested every ounce of patience I had over a 3 + month period of time during their transition from dry to canned food.  They had been on dry food their entire lives and did not recognize canned food as food.  My cats ranged in age from 2 years to 10 years at the time of the transition.

The single biggest mistake I see people make time and again is to say that their cat "won't touch" the new food and then panic and fill up the bowl with dry food.   In many cases, it is simply not that easy to get cats off of dry food. (See Molly's Story for a look at one very stubborn cat.)

There are two categories of cats - those that will eat canned food and those that will be extremely resistant to eating anything other than dry food.  If your cat falls into the first category, lucky you. These cats will take to it with the attitude of “finally – an appropriate diet for my species.”   In this case, if your cat has been on all dry food, or only receives canned food as an occasional 'treat', start by feeding canned food in increasing amounts.  Gradually decrease the dry, taking about a week to fully switch the cat over to 100 percent canned food.

Some cats may experience softer stools during the transition.  I do not worry if this happens and tend to 'ride it out'.  If diarrhea results from the diet change you will either need to experiment with different canned foods or slow the transition down and do it over a period of several weeks.

Note that in over 35 years spent in this profession, I have never met a cat that needed dry food to stay healthy but some need to be transitioned more slowly than others.

The average cat should eat 4-6 ounces of canned food per day split between 3-4 meals/day (or just free-fed if they are not overweight) but this is just a general guideline.  When determining how much you should be feeding your cat once transitioned to canned food, keep it simple.  Too fat?  Feed less.  Too thin?  Feed more.

Andy and Calvin

Now....for the stubborn cats......

If you are unlucky like I was, and your cat does not recognize the fact that he is a carnivore and would live a healthier life if eating canned food, (or a homemade diet) then you will have some work to do.  Some cats that have been on dry food for their entire life will be quite resistant to the diet change and may take several weeks or longer to make the transition to a healthier diet. 

For 'resistant-to-change' cats, you will need to use the normal sensation of hunger to help with the transition. For this reason, it is very important to stop free-feeding dry food.  This is the first, and very critical, step.  You need to establish set mealtimes. They are not going to try anything new if their bowl of junk food is in front of them 24/7.

Cats do not need food available at all times. It really is okay for them to experience a hunger pain!  That said, it was very hard for me to listen to my cats begging for food even though I was strong in my conviction that I was heading them in the best direction for optimal health.  It truly was a stressful time for me and them.  Actually, I think it was harder on me!

This is where many people fail and just give in and fill up the dry food bowl.  There were a few times when I had to call my 'sponsor' and was instructed to "just leave the house if you can't take looking into those eyes!"  I left the house. Those pitiful little cries of "I have not had food for two WHOLE hours!" were hard to take.  But, lo and behold, they were just fine when I returned.  Not one cat had died from hunger.

On the other hand, do not attempt to withhold food for long  periods of time (greater than 24 hours) with the hope that your cat will choose the new food.  You need to ‘convince’ them that a high quality canned food  really is good for them, rather than to try starving them into it - which does not work anyway.  Allowing a cat to go without food - especially an overweight cat - for a long period of time (greater than 48 hours) can be quite dangerous and may result in hepatic lipidosis (fatty liver disease).

Hepatic lipidosis can also develop when a cat consumes 50% or less of his daily caloric requirements over a period of many days.  The definition of "many" varies from cat-to-cat.  For this reason it is important to understand that you need to have some idea of the calories from canned food combined with the calories from dry food that your cat is consuming on a daily basis while you are implementing the transition to canned food. 

I have never seen a cat develop hepatic lipidosis when consuming at least 15 calories per pound per day.  This number is figured on lean body weight, not fat weight. 

If your cat weighs 18 pounds but really should weigh 12 pounds, please make sure that he is consuming  ~180 calories per day.  (12 pounds lean body mass X 15 calories/pound/day = ~180 calories/day)

In reality, the cat in the above example would probably be completely safe at only 150 calories per day.

If you have a small female cat that should only weigh 9 pounds, please make sure that she is consuming at least 135 calories per day.

Canned foods never list the calorie content on the can but many dry foods do list this information on the bag.  A rough guideline for the calorie content of most canned foods that are 78% moisture is ~30 calories/ounce but can range from 20 to 40 calories/ounce as shown by the chart linked above.

Most cats will lose some weight during the transition to canned food.  Given that a very high percentage of cats are overweight to begin with, this is a favorable result of the diet change - as long as they do not lose too much weight too fast.  A cat should never lose more than 1-2% of his body weight per week.

I highly suggest that all cat caregivers weigh their cats periodically especially if they are over 10 years of age.  This will help ensure a safe transition to a healthier diet and, in general, weight loss is often the first sign of ill health for any reason.  I make it a point to weigh my cats at least every 2 months especially since they are now over 10 years of age.

Here is a scale that is reasonably priced:  Salter Baby and Toddler scale.  It weighs to the nearest  1/2 ounce and has a 'hold' button on it  that helps obtain an accurate weight even for a cat that is moving around a bit.

Here is another scale that may be even better because its base is as long as the scale.  Red Cross Baby Scale. This is important for cats that are trained to walk onto it otherwise, scales like the Salter one linked above may tip.  This would scare the cat and harm the scale.

All of my cats lost weight during the three months that it took to switch them to canned but none of them became too thin.  They slimmed down to a nice lean body weight - losing fat while maintaining their muscle mass.  They also became much more active.

If your cat is overweight, please see the Feline Obesity page.

Resign yourself to the fact that you will be very frustrated at times and you will be wasting canned food as they turn up their nose at it.  Also, you may want to immediately switch your cat to a dry food that has fewer calories from carbohydrates than most dry foods. (e.g., EVO) 

The low-carb dry foods are very high in fat and therefore are very calorie dense.  These foods must be portion-controlled otherwise, your cat may end up gaining weight.  Note that dry Innova EVO has 612 calories per cup.  One quarter of a cup contains 153 calories so be very careful to pay attention to how much of these high calorie dry foods you feed.

The caloric needs of an average cat can range between 150 - 250 calories/day depending on their lean body weight and activity level.

The low-carb dry foods are also very high in phosphorus.  This is especially detrimental for cats with compromised kidney function.

And, of course, these low-carb dry foods are water-depleted - just like all dry foods - putting your cat at risk for serious urinary tract problems.  They are also cooked at very high temperatures in order to dry them out.

I do not recommend these dry foods for long-term feeding for all of the reasons stated above.   Please use them only as transition diets. 

Be sure to stay away from any "light" varieties since those types of foods are very high in carbohydrates.

Here are some various tricks for the stubborn ones. 

Keep in mind that different tricks work on different cats:

• If your cat has been eating dry food on a free-choice basis, take up the food and establish a schedule of 2 - 3 times per day feedings.  I really do prefer just twice-daily feedings when trying to transition them.  A normal, healthy hunger response after 12 hours goes a long way to convince them to try something new.

  Once the cat has transitioned to canned food, I prefer to either free-feed them (if they are not too fat) or to put out a meal 3-4 times per day. Small cats in the wild eat 8-10 small meals per day. I do not worry about leaving canned food out for up to 12 hours at a time. Keep in mind that a lion is not going to eat his entire prey immediately.

  If you want to take the transition very slowly, you can feed the amount that your cat normally consumes in a 24 hour period - split up into two feedings to get him used to meal feeding.  Many people, however, are unsure as to how much their free-fed cat really eats so I would start off by figuring out the calories that your cat needs to maintain his weight if he does not need to lose any weight.

  Again, most cats only need 150-250 calories/day.  The dry food bag should tell you how many calories are in a cup of food but if it does not, you can call the company.

  Leave the dry food down for 20 minutes, and then remove any uneaten portion.  Repeat in 8-12 hours depending on if you are feeding 2 or 3 times per day.  During the first few days of transitioning to a set schedule, you can offer canned food during the dry food meals, or in-between meals.  The stubborn ones, however, will not touch it.  Do not despair - all cats will eventually eat canned food if their caregiver is determined, methodical, and patient enough.  Once your cat is on a schedule you will notice that he is more enthusiastic about food during his proper mealtimes and will be much more inclined to try something new.  

• Once you have established scheduled mealtimes, you will most likely need to start feeding a bit less at each mealtime in order to get the normal sensation of hunger to work in your favor.  Again, we are trying to use the normal sensation of hunger to help us out.  We are not trying to starve the cat into the diet change.

• Once your cat is on a schedule of meal-feeding instead of free-feeding, try feeding a meal of canned food only.  If he will not eat it - and the very stubborn ones won't - try not to get frustrated - and do not put down dry food.   Try some of the other tips listed below.   If he still will not eat the canned food, let him get a bit hungrier.  Offer the canned again in a couple of hours - or just leave it out.  Some cats will be more apt to try something new if they keep walking by it and seeing/smelling it.  Try a different brand/flavor or a different 'trick'.  Once it has been ~18 hours since he has eaten anything, give him just a small amount (1/4 of a cup - or less if it is EVO) of his dry food - keeping track of his daily caloric intake. 

• Remember to be patient.

• Exercising your cat with a tassel toy before feeding can also help stimulate his appetite.

• Cats' noses are much more sensitive than ours are.  They can smell the dry food in the cupboards.  I suggest either putting it in the refrigerator or putting it in a tightly sealed container.  If they can smell it, they will hold out for it.  Some people recommend getting it out of your house completely, but this is not possible when you are dealing with a very stubborn cat that needs a bit of time and patience to make the transition happen.

• The following worked for my cats:  Sprinkle a very small amount of tuna – or any other favorite treat (some cats do not like fish and would prefer cooked chicken) - on top of the canned food and then once they are eating this, start pressing it into the top of the new food. (The “light” tuna is better than the fancy white tuna because it has a stronger smell.  Or, Trader Joe’s makes a Cat Tuna that is very stinky.)  Be careful to decrease the amount of fish as soon as possible.  Health problems can occur with a predominantly fish-based diet.  Plus, you do not want to create a situation where your cat will only eat very fishy foods.

• Make sure that any refrigerated canned food is warmed up a bit.  Cats prefer their food at 'mouse body temperature'. 

• Try offering some cooked (or raw - whole meats, rinsed well or partially baked) chicken or meat baby food.  One of the goals is to get your cat used to eating food that does not crunch.  He needs to get used to a different texture.  Also, chicken is a great source of protein to point him in the proper direction toward a high protein, low carbohydrate diet.  If he eats the chicken, he may head right into eating canned food.  Then again....he may not.

• Try sprinkling some parmesan cheese on the canned food.  Most cats love parmesan cheese and this trick has been very successful for me.

• Try a product called FortiFlora - feline version.  Most cats LOVE FortiFlora and this has recently become my favorite trick.  This is a probiotic made by Purina but you are not going to use it for its probiotic properties.  You are just going to use it as a flavor enhancer.  The base ingredient in FortiFlora is animal digest - the very substance that makes dry food so very enticing to cats.  The directions say to use 1 package/day - and you can use this much if you want to - but this amount is not usually necessary.  You may only need ~1/4 of a package - or much less - with part mixed into the food and part sprinkled on top of the food just as you would use salt and pepper on your own food.

FortiFlora can be purchased online but an easier product to find is Temptations treats.  I trap a lot of feral cats for spaying/neutering purposes and this is one of the best baits that I can use.  These tasty treats can be found at most pet stores.  Put a few in a baggie and crush them with a hammer.  Use the crushed treats as described for the FortiFlora above.

• There are numerous freeze dried meat treats on the market that you can also sprinkle on top of the canned food.  Halo's Liv A Littles is a popular choice.

• Speaking of texture, a common question is "can I just soak the dry food in water?"  I hedge more than just a bit at this question.  Dry food often has a very high bacterial content.  Mold is also often found in dry food.  Both organisms flourish in moist environments. There have been many deaths of dogs and cats secondary to eating mold mycotoxins, vomitoxins and aflatoxins which often contaminate the grains found in dry food.  If you want to try the trick of wetting down the dry food to alter the texture, please leave it out for only 20-30 minutes then discard it. 

• Try dipping some dry food pieces in the juice from the canned food.  Some cats may refuse to eat it if the dry food even touches the canned food.  But if he will eat it with a bit of canned juice on it, try the 'chip and dip' trick.  Scoop up a tiny bit of canned food onto the piece of dry food. Put them on a separate plate from his small portion of dry food.  Some cats will eat their small portion of dry and then go investigate the dry food with a tiny bit of canned on it.

• Going one step further, try adding a few small pieces of the canned food to the small portion of dry food.  Your cat may pick around the canned food but will get used to the smell - and texture - even if he does not eat any pieces of the new food.

• Crush some dry food and sprinkle it on the top of the canned food.

• If you do not think it will upset your cat, try gently rubbing a bit of canned food or juice on the cat's gums  This may get him interested in the taste and texture of the new food - but do it gently.  You do not want to make this a stressful situation and create a food aversion.  (This trick is commonly used to get just-weaned kittens used to eating canned food.)

• If you do not think it will upset your cat, use your finger to put a tiny bit of canned food or juice on his paw for him to lick off.  This has not worked for me in the two cats I have tried it on but it is another idea.  Make sure you do it without stressing your cat.  Again, you do not want to create a food aversion.

• If you have a multiple cat household, some cats like to eat alone in a less stressful environment, so you may need to take these cats into a separate, quiet room to think about the error of their ways - their carbohydrate/dry food addiction. Once in a quiet setting, away from the other cats, two of my cats would eat canned food/tuna ‘meatballs’ by hand.  Not from a bowl, mind you, but only from my hand. I’m not sure who was being trained. They did eventually start eating from a bowl after a few hand feedings.

• Try various brands and flavors of canned foods.  Try Friskies, 9-Lives, Fancy Feast, etc.  Many cats prefer the foods that are all by-products and turn their noses up when offered the by-product-free diets like Wellness, etc. You can worry about feeding a a different canned food later if you want to and you can always mix different types of food together.  The initial goal is just to get your cat used to eating canned food and not dry kibble.  And remember what I said above. I would much rather see a cat eating a canned food like Friskies, 9-Lives, or Fancy Feast rather than any dry food.

• Syringe-feeding is also another option but has to be done with finesse and patience so as to avoid a food aversion.  If you choose to syringe-feed, your goal is not to feed him a full meal.  Sometimes just syringing a 1-2 cc's can 'jump-start' your cat into eating the canned food - maybe not the first time but it will at least get him to taste the new food and experience a foreign texture. The best way to syringe-feed is to kneel on the floor with your cat between your legs so he is facing the same way as you are.  Then, using a small (1cc/TB) syringe, slip it in the side of his mouth and give about 1/2 cc at a time.  He may spit it out but you are just trying to get him used to the taste and texture, not stress him.

Few canned foods will make it through the tip of a syringe but human meat baby food works well for this trick. You can also water it down a bit if you need to.

If you want to use canned cat food instead of baby food, you will need to cut the end off of the syringe so that the opening is as big as the barrel.  Make sure that the tip is smooth.  If you do not want to cut the tip of the syringe off, you will need to puree a pate (versus chunks) type of food.  I puree Wellness for this.  I run it through the blender with a small amount of water (~3-4 tablespoons/5.5 ounce can).  Then I strain it to remove anything big enough to clog the small tip of the syringe.  Wellness is also a balanced diet - unlike human baby food.

Even though human baby food is not a balanced diet for long-term use, it is a great tool that can be used to help transition a cat to a texture that he is not used to.

• I did have to take drastic measures for a foster cat named Molly.  She was dangerously obese (20 lbs - double what she should have weighed) and would not eat canned food even after two weeks of syringe-feeding her.  She needed to go in for a dental so while she was under general anesthesia, I put in a feeding tube.  This took the stress off of both of us.  After two weeks of feeding her via the tube she started licking the canned food from my fingers then suddenly decided it was time to eat it.  She then started to finally lose weight.  Before the 7 lbs weight loss, she could barely walk, could not clean herself, and was quite possibly headed for diabetes.

• Don't give up.  One of my barn cats ate dry food for the first 12 years of her life.  She would never touch the canned food that the other cats ate. Then, one day, she found her 'inner carnivore' and started eating canned food out of the blue!  I was shocked.  That was 4 years ago and she has been on a 100% canned food diet since she made the switch.

These are just a few tricks that you can try.  Different tricks work on different cats.  The key is to be patient.  Remember, it took me three months to get my cats on 100% canned food.  Most cats, however, will not take this long.   

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Robbie waiting for dinner

Cat food headed for the freezer

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Some Final Thoughts

Congratulations if you have made it to this point in this article.  You must really care about feeding your cat a healthy diet and are open to new ideas regarding their nutritional needs.  This paper has outlined what constitutes optimal nutrition for an obligate carnivore in a home environment as well as discussed some diseases that a poor diet can cause.

The most common complaint that I hear from people is that their cat will NOT eat canned food and will ONLY eat dry food. 

My cats fell into this category which was not surprising since they had been on a 100 percent dry food diet their entire lives and ranged in age from 2 -10 years at the time of the transition to a healthier diet.  It took me several months to convince them that they are carnivores and need meat – and not in a dry, overly processed form that also includes far too many carbohydrates and too little water. It was a little rough, at times, since two of my cats get very crabby with their housemates when they are hungry. These boys were occasionally taken into a separate room during the transition period and fed some dry food because I do not like unrest in my home. 

Who?  Me??  Crabby?

I have not fed any dry food to my cats for 10 years and I can't imagine ever feeding my cats this type of diet again.  Cats do not need, or benefit from, any dry food in their diet.  They also do not need access to food 24 hours a day although my cats are pretty much free-fed.

Many people who are at work all day worry that their cat will suffer without access to food continuously.  A healthy cat will not perish if she does not have food available at all times.  However, I routinely left canned food out for up to 12 hours at a time for my foster cats and kittens when I was involved in rescue work.  Keep in mind that a cat's gastrointestinal tract is much different from ours.

If you are worried about leaving canned food out, you can always leave part of the food out at a normal (‘mouse body’) temperature and part of it frozen.  The frozen portion will thaw within a few hours and will add some time to the 'freshness' of the food.  This is also a great trick if you need to be gone for 24 hours or if your pet sitter can only come every 24 hours when you go on vacation. 

There is never any reason to revert back to sitting out a bowl of dry food since cats should be checked on – including having their litter box cleaned – at least once every 24 hours anyway.  Normally litter boxes should be cleaned at least twice-daily so if they are only going to be cleaned once-daily, you should consider adding another box or two….keeping mind that once there are more than 2-3 ‘items’ in a box, it is dirty and needs to be scooped in order to be fair to your cat(s).

Everyone's lives are different and there are several ways to successfully feed your cat high quality nutrition.   The goal of this paper is to arm you with knowledge regarding the special dietary needs of your cat so you can make an informed decision on how and what to feed while striking a balance that works for both of you.