Feline Diabetes and Diet:  The High Carbohydrate Culprit

Lisa A. Pierson, DVM

Warning:  Before reading even the first sentence of this webpage, you must commit to reading past the STOP sign below.

Diabetes is one of the most common feline endocrine diseases and, in the vast majority of cases, is directly linked to a high carbohydrate diet of dry food.  Although all dry foods are too high in carbohydrates, please be aware that many canned foods also contain far too many carbohydrates making them very poor choices for cats.

Feeding a diabetic cat a high carbohydrate diet is analogous to pouring gasoline on a fire and wondering why you can't put the fire out. 

Cats are obligate carnivores and are not designed by nature to consume a high carbohydrate diet.  If you have not read my article on this site entitled Feeding Your Cat: Know the Basics of Feline Nutrition, I urge you to do so.  This article explains why it is terribly illogical to feed any cat dry kibble, but especially one with diabetes.  The rationale also applies to any of the prescription dry diabetes diets such as Purina DM and Hill's Science Diet w/d and m/d.  These diets are not only poor quality diets, they are still too high in carbohydrates and contain several species-inappropriate, hyperallergenic ingredients.

Please understand that there is nothing 'magical' about these diabetes-management diets other than the fact that they are lower in carbohydrates than the majority of cat food products on the market. 

As this webpage points out, it is very important to address the carbohydrate level in a cat's diet but it is 'tunnel vision' nutrition to stop there.  We need to address the quality of the ingredients in the foods that we feed to our cats - not just the carb level. 

Both issues (carb level and nutrient quality) are important since we are feeding the whole cat, not just the disease of diabetes. 

None of these prescription diets will find their way into a food bowl for any cat in my care since there are many other more nutritious - and less expensive - alternatives that can be purchased over-the-counter.

See this chart for the carbohydrate content of many canned foods.  Aim for below 10% of calories from carbohydrates.  Keep in mind that this chart only addresses the food's composition in terms of calories from protein/fat/carbohydrates and does not address the quality of the ingredients.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                 Very Critical Points

If you do not read any further on this webpage, please understand the following principles.  Your cat's life literally depends on your understanding of these issues.

Many cats that are in a diabetic state no longer need any insulin when they are finally fed an appropriate low carbohydrate diet.

If the diabetes has been a long-standing condition brought about by years of feeding a high carbohydrate diet, or another disease process, these cats may always need some insulin but the amount necessary to maintain proper blood glucose levels is nearly always significantly reduced once the patient is on a low carbohydrate diet.

Please re-read the previous two paragraphs carefully. 

If you change your diabetic cat's diet to one with lower carbohydrates, he will, in all probability, IMMEDIATELY (not days or weeks later) require a reduction in his insulin dosage.  He may also immediately go into 'remission' and not need any insulin at all. 

If this warning is ignored, you may very well end up with a cat in a hypoglycemic crisis (dangerously low blood sugar) which can result in death, or brain damage.

If you take only one point away from this page, it needs to be the understanding that if you stop pouring carbs into your cat by switching to a low carb canned food diet (or even a dry food diet with lower carbs than you have been feeding), you MUST be aware of the probable immediate and significant impact on your cat's insulin needs.

If I could shout this from the rooftops, I would. 

On a weekly basis, I hear of reports of cats that ended up near-death - or actually did die - from insulin overdoses because lay caregivers and veterinarians did not understand this basic concept.

I often hear of my colleagues recommending "re-testing in a month" - while the caregivers are implementing a diet change along with administering a set amount of insulin - which is often too high.

Or - the caregiver reads this article and decides to change the diet on their own and does not understand the need to lower the insulin dosage.

When someone understands half of the concept (changing to a low carb diet), but does not understand the other half of the concept (the highly probable need to lower the insulin dosage) disaster often strikes.

Remember the statement that I made above?  The one about pouring gasoline onto a fire?  If you stop pouring gas on a fire, there is going to be an immediate reaction of that fire when its fuel is taken away.  That fire is not going to take weeks or a month to respond.

In this analogy it would not be a big issue if you kept 'drowning' that dying fire with water but in this instance water = insulin and a hypoglycemic crisis will ensue if more insulin is given than is needed by the body.

Of course, carbohydrates are not the only fuel for a diabetic 'fire' but they play a very significant part in contributing to high blood sugar levels in a diabetic cat.  If you minimize this issue - and do not lower the insulin accordingly -  you really will be 'playing with fire' with regard to the safety of your cat.

So you say - "OK!!  I get it!  I understand that my cat may very well need a lower dose of insulin - or may not need insulin at all - once I stop pouring gasoline (carbs) onto his diabetic fire, but how do I know what dosage of insulin to give?  How do I know what impact the new diet is going to have on his insulin needs?  How do I keep my cat safe?"

This is where in-home blood glucose monitoring comes into play.

Trying to manage a diabetic cat without home testing is like driving a car with a paper bag over your head or playing Russian Roulette with several bullets in the gun.

Unfortunately, every case is different and definitive recommendations with respect to how far to lower the insulin dosage (when you start the diet change) cannot be given without knowing the specifics of each case.  There are many crucial factors to be considered:

• carbohydrate content of the original

• carbohydrate content of the new diet

• how fast the change to a low carb diet is made

• how quickly the cat's body responds to the decrease in carbs

• how the cat, in general, reacts to insulin

• has the cat ever been positive for ketones in his urine

• current dosage of insulin

• current blood glucose levels of the patient

• etc.

The only way to arrive at the optimal dosage of insulin and the optimal dosing frequency is by home testing.  Note that I said "optimal".  Many diabetic cats have survived for many years with a set amount of insulin being administered twice daily with the dosage determined by periodic glucose curves performed at a veterinary clinic.  Unfortunately, this is not the safest and most physiologically sound way to manage a diabetic patient.

I urge you to keep the lines of communication open between you and your veterinarian while learning to home test and implementing the diet change.  That said, it is unfortunate that many veterinarians are not well-versed in the management of feline diabetes and all too often do not fully understand the strong connection between diet and blood sugar levels. 

It is also very frustrating to note that many veterinarians either are not aware that home testing is possible (despite the subject being discussed in various veterinary journals) or just simply do not support this life-saving tool.

Additional help and support can be found on the Feline Diabetes Message Board and I strongly urge all diabetic cat caregivers to join this forum. 

Your Diabetic Cat is another helpful forum and is owned by Dr. Elizabeth Hodgkins.  This forum is geared toward a more aggressive form of diabetes management referred to as "tight regulation".

Keep in mind that with all internet forums, the experience and knowledge base of the participants will vary. 

If posting to forums is not within your comfort zone and you would like additional help, I am available for phone consultations.  Please understand that I cannot offer individual case advice via email.  Feline diabetes can be a very complicated disease to optimally manage and it would not be ethical or time-efficient to attempt to address individual case management of this disease via email. 

If you have read Feeding Your Cat: Know the Basics of Feline Nutrition along with the first part of this webpage and are convinced that you need to start feeding your cat(s) correctly (low-carb, canned or homemade food) and want to skip the rest of this article, please head right to the changing the diet safely and the home testing sections below.

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

If you want to know more about the physiology of diabetes and why a low carbohydrate diet is so important for this species, please click on the links below.

The basics of diabetes

The cat's unique metabolism

Carbohydrates, obesity and diabetes

Optimal nutrition for all cats

Switching the Diabetic Cat to a Low Carbohydrate Diet - SAFELY!

In-home blood glucose monitoring

The Basics of Diabetes

All cells in the body use glucose ("blood sugar") as their source of energy.  However, in order for glucose to provide nourishment to the cell, the glucose must get inside the cell.  Insulin, which is produced by the pancreas, is the substance that tells the 'front door' of the cell to open up in order to let the glucose inside.  If this system is disrupted for any reason, the glucose cannot enter the cell and subsequently, the level of glucose increases in the blood stream (hyperglycemia) and the cells go 'hungry'.

There are two types of diabetes.  Type 1 and Type 2.  Type 2 is the more common form in both humans and cats.

Type 1 occurs when the beta cells of the pancreas are not able to produce enough insulin.

Type 2 is characterized by two problems.  The first, as in Type 1, is a diminished ability of the pancreas to secrete insulin.  The second issue is one of insulin resistance.  In other words, the receptors on the cell wall that would normally open the door to the cell to let the glucose in when insulin 'knocks', stop 'listening' to the insulin. The cells 'resist' the signal that the circulating insulin is sending and the glucose is not transferred to the inside of the cell, resulting in an elevated blood glucose and cellular 'starvation'.  The elevated blood glucose, in turn, sends a signal to the pancreas telling it to secrete more insulin.  The elevated insulin may somewhat override the insulin resistance resulting in more glucose entering the cells, but eventually the pancreas can become exhausted or 'burned out'.

Here is a picture of the pancreas.  It is the long, flat, pink organ in the center.  The dark red organ below it is the spleen.  The white tissue is all fat - the result of an inappropriate diet of high carb dry food.   This is also called "omental fat" and some of you may have heard or read about this type of fat in humans.  It is the fat that is carried around the abdomen and is associated with significant health problems.

The Cat's Unique Metabolism

In my article, "Feeding Your Cat: Know the Basics of Feline Nutrition", I explain what it means to be an obligate carnivore.  For a more technically detailed presentation of this subject matter, please see Dr. Debra Zoran's wonderful article entitled The Carnivore Connection to Nutrition in Cats.  

Cats are obligate carnivores and, as such, are uniquely adapted to consume a diet that is high in protein, contains a moderate amount of fat, and that includes a very small amount (3-5 percent) of carbohydrates.  Since nature designed them to ingest very few carbohydrates, cats lack many of the important enzymes that are necessary to process this type of food efficiently.

With the above information in mind, consider the fact that the carbohydrate level of most dry foods is between 35-50 percent with some of the lower quality dry foods being even higher.

Robbie has been designed by nature to eat meat, not grains.

Read on to understand why this disparity in the carbohydrate level found in commercial foods versus nature so commonly results in a cat developing diabetes.

The three main 'take-home' words from my Feeding Your Cat article are "proteins" (animal versus plant), "water", and "carbohydrates".   For this article, the most important of the three subjects is carbohydrates.

Carbohydrates, Obesity and Diabetes

Most people are aware that diabetes is more common in overweight humans than it is in people closer to an optimal weight.  The same is true for cats.  Fat (adipose) cells produce a substance that increases the resistance of the body's cells to insulin.  This increase in insulin resistance is the hallmark of Type 2 diabetes.  As mentioned above, this is the most common form in the cat.

Cats are designed to utilize proteins and fats for their energy - not carbohydrates.  They are lacking the necessary enzymes to efficiently utilize carbohydrates to meet their energy needs.  When the carbohydrate level of an obligate carnivore's diet is higher than it should be - remember that a bird or a mouse is only 3-5 percent carbs and that most dry foods contain between 35-50 percent carbs - the excess carbohydrates are stored as fat.  The increased fat cells, in turn, promote Type 2 diabetes via an increase in insulin resistance.

Mindy (left) is nice and lean and full of energy.  Molly (right) was rescued from  a home where only dry food was fed and she had become terribly obese.  She could barely walk and could not even clean herself.  She has gone from 20.5 pounds to 14 pounds simply by eating a low-carbohydrate canned food (Wellness) and having all dry food removed from her diet.  She now runs, jumps and plays like a normal cat!  For more on her story click here and here.

Not all carbohydrates are created equal, but it is safe to say that obligate carnivores - especially diabetic ones - do not benefit from carbs at a level above what would be in their natural diet regardless of the type.  But that said, carbohydrates are characterized by their Glycemic Index (GI) and their Glycemic Load (GL) which are measurements that reflect how high and how rapidly a specific carb causes a rise in blood glucose when ingested and the overall impact that particular carb has on the diabetic state.  The higher the GI/GL of a carbohydrate, the worse the result will be for a diabetic patient.

The Glycemic Index and Glycemic Load values of different food sources are very important to consider for people trying to manage their own diabetes.  However, I do not like to concentrate on these values for cats because then it sounds like there may be "good" carbs versus "bad" carbs for cats.  The bottom line is that humans are designed to utilize carbs whereas cats are not.  What we can say is that some carbs are worse (higher GI/GL) than other carbs, but ideally, we should strive to keep the carb level of the feline diet at a level which would be found in nature. 

Please keep in mind that corn, wheat and rice are very common ingredients in many pet foods and that these species-inappropriate grains have relatively high Glycemic Index and Glycemic Load values.  Also, when you see the word "flour" know that the flour of any grain has a higher GI/GL load than the grain when it its whole form.

Please see my list of Commercial Canned Food Choices.  This list was originally compiled in order to benefit the IBD (Inflammatory Bowel Disease) cats that I work with.  The culprit in this disease process is often specific hyperallergenic grains such as corn, wheat, and soy.  In addition to these grains, yeast is also hyperallergenic. So for this reason, you will note that the list is split into two sections - With Grains and Without Grains.   The "With Grains" list only includes products that do not contain corn, wheat, or soy.

For the diabetic cat, however, the caregiver should ideally focus on keeping all grains out of the diet.  While an IBD cat may be able to tolerate rice, this is definitely not an ingredient that you want to feed to a diabetic cat - or any cat, for that matter.  Rice has a very high GI/GL value. On the other hand, the varieties that do not contain grains are naturally very low in carbohydrates.

Buck still needs to lose a bit more weight on his low-carb diet.

Subtracting all of the percentages on the label (using 'nutrient analysis' and not 'guaranteed analysis', preferably) from 100 percent gives you an approximate percentage (of the total weight) of the carbohydrates contained in any product. In other words, subtracting the protein, fat, water, fiber, and ash/mineral content from 100 percent will leave you with the percentage of carbohydrates contained in the diet on an 'as fed' basis which still takes the water content into consideration.  Unfortunately, the math does not stop there because it is much more useful to determine the carbohydrate level on a 'dry matter basis' which results in a value that is not influenced by the water content of the diet.  Using dry matter basis values allow you to compare all foods - both dry and canned - on an equal basis.

As fed numbers are always much lower than dry matter basis numbers.

Example:  AvoDerm Cat/Kitten canned food contains 3% carbohydrates on an as fed basis but really contains 13.5% carbohydrates when the influence of the water is removed and the nutrient is figured on a dry matter basis.

Remember to never compare as fed numbers with dry matter basis numbers.

A very valuable site that lists the carbohydrate content of many commercial foods is the SugarCats site.  This site lists values that are percentages of calories, not percentages of weight. This can get very confusing and lead people to wonder why two different lists show different numbers for the same product.  For instance, most pet food manufacturers list the ingredient numbers for their products as percentages of weight, not of calories.  Both methods are perfectly acceptable but this does lead to a lot of confusion. 

Unfortunately, many of the foods on my list are not included in the SugarCats list but you can do your own rough calculations or email the companies and ask them for their carbohydrate values.

For more information on how the food tables are compiled, click here. 

Optimal Nutrition for All Cats

We have all heard the phrase 'locking the barn door after the horse is gone'.  This applies to how we feed our cats with respect to the diseases that they commonly develop secondarily to being fed a low quality, species-inappropriate diet.  For instance, when looking at feline diabetes, notice that the rationale behind the Purina DM prescription diet is to provide a decreased carbohydrate level in the food to treat a diabetic cat.  Why not recommend a decreased level of carbohydrates for all obligate carnivores to prevent diabetes?  Why are we always addressing treatment rather than prevention?  Why aren't more veterinarians making common sense-based recommendations for their healthy patients in order to prevent diseases such as diabetes and IBD that are so often associated with a high carbohydrate diet/high grain diet?

While the optimal diet for an obligate carnivore is one with less than 5 percent carbohydrates, you should strive, at a minimum, to keep their diet below 8-10 percent carbohydrates.

The subject of fiber is also widely discussed with respect to feline nutrition and diabetes.  It was once thought that a high fiber diet would be beneficial for the diabetic cat but this recommendation has since fallen out of favor.  Please see Dr. Zoran's article for more details and also this study.  A cat's natural diet is not very high in fiber and, contrary to what is seen in dogs and humans, it is not in the cat's best interest to feed a diet high in fiber.  Cows and horses are designed to eat a high fiber diet - not cats.

Let's take a look at some of the ingredients and the carbohydrate content in several prescription diets often recommended for diabetic cats.  I have underlined the sub-optimal and species-inappropriate ingredients.  For a more in-depth look at reasons why these ingredients do not constitute optimal nutrition, please see my Feeding Your Cat article.  In summarizing the points in that article, please take note of the fact that the Hill's Science Diet products listed contain no high quality muscle meat.  Cheap, low quality by-products or organ meats are used instead.  In addition, note the high carbohydrate levels in all of the listed products except for the Purina canned DM, the common usage of high glycemic index grains of which some are also known as hyperallergenic ingredients - namely, corn, rice, wheat, soy and yeast - and the use of known carcinogenic preservatives.

Hill's Science Diet dry m/d:   (16% carbohydrates)

Chicken by-product meal, corn gluten meal, pork fat (preserved with mixed tocopherols and citric acid), pork protein isolate, corn meal, powdered cellulose, wheat gluten, dried egg product, chicken liver flavor*, L-lysine, taurine, rice flour

Hill's Science Diet canned m/d:  (16% carbohydrates)

Pork by-products, pork liver, water, corn starch, powdered cellulose, soy protein isolate, chicken fat (preserved with mixed tocopherols and citric acid), guar gum, locust bean gum, carrageenan, rice flour

Hill's Science Diet dry w/d:  (37% carbohydrates)

Chicken by-product meal, corn gluten meal, brewers rice, rice flour, powdered cellulose, chicken liver flavor*, vegetable oil, pork fat (preserved with mixed tocopherols and citric acid), taurine, L-carnitine, preserved with BHT, BHA and ethoxyquin

Hill's Science Diet canned w/d:  (28% carbohydrates)

Pork by-products, pork liver, water, corn flour, powdered cellulose, chicken fat (preserved with mixed tocopherols and citric acid), chicken liver flavor*

Hill's Science Diet canned w/d with* chicken: (26% carbohydrates)

Water, pork liver, pork by-products, chicken, powdered cellulose, starch, oat fiber, guar gum, locust bean gum, carrageenan, chicken liver flavor*

*Please be aware that the word "with" means that a product is required to contain only 3% of the ingredient - in this case, chicken.  Also, the word "flavor" means that the product is not required to have any of the ingredient present.

Now let's look at two Purina products:

Purina dry DM:  (15% carbohydrates)

Poultry meal, soy protein isolate, corn gluten meal, soybean flour, beef tallow preserved with mixed-tocopherols (source of Vitamin E), corn starch,.....brewers dried yeast

Purina canned DM:  (8% carbohydrates)

Liver, water, beef, corn gluten meal, trout, fish meal, beef tallow preserved with mixed-tocopherols (source of Vitamin E), wheat flour, soy protein isolate

When comparing the Hill's products with the two Purina DM choices, if I had to choose between them, I would pick the Purina canned DM.  But fortunately, we do have other choices.  One of the biggest mistakes I see veterinarians make is choosing a diet based on addressing a single disease entity.   This is very narrow-sighted.  The Purina canned DM very favorably addresses the overall carbohydrate level but it also contains corn, wheat and soy and it contains predominantly liver versus a muscle meat.  These ingredients are certainly not what a cat would choose to eat in the wild. 

I choose to feed a cat for overall health, not just to address one disease state such as diabetes - especially when there are products available that are even lower in carbohydrates and contain far superior ingredients for carnivores than the products listed above.  When I look at the Hill's and Purina ingredients, these are certainly not products that I would choose to feed my own cat.

I realize that there are cats who, at first, refuse to eat canned food.  For these cats, the Purina DM dry is the best alternative until a better diet can be fed.  I am a firm believer that all cats will eventually eat canned food if various tricks are tried and the human outsmarts the feline and uses a healthy dose of patience and perseverance.  It is definitely more difficult with a diabetic cat due to the fact that they must eat on a schedule, but it can be done.  I see people 'throw in the towel' far too soon on these stubborn, dry food-addicted cats.  The lifespan of your diabetic cat will be prolonged if he is not fed dry food.

Let's now take a look at look at canned Wellness:

Wellness canned Chicken:  (Most varieties range from 2-5% carbohydrates)

Deboned Chicken, Chicken Liver, Turkey, Chicken Broth, Sweet Potatoes, Carrots, Vegetable Gums, Flaxseed, Potassium Chloride, Alfalfa, Cranberries, Blueberries, Yellow Squash, Yellow Zucchini

Note the absence of any grains and the very low carb content.  Also note the high level of muscle meat - versus by-products and organ meat - and the lack of any dangerous preservatives.  These products are also void of the commonly used hyperallergenic and high glycemic index ingredients such as corn, wheat, soy and yeast.

On a negative note, I wish they would leave out the sweet potatoes and all of the vegetables.  Cats do not need vegetables and many cats simply cannot handle vegetables in their diet.  Be aware that a small percentage of cats will develop diarrhea when fed canned Wellness and I believe it is due to the vegetable content.

Surprisingly, contrary to what the name implies, sweet potatoes have a lower GI/GL than the common white potatoe. Still, it would be preferable for this ingredient to be absent from a cat's diet.  Unfortunately, all commercial diets have some cons associated with them which is why I choose to make my own cat food. 

The reader may be wondering why I have not listed dry Wellness.  This is because cats - especially diabetic cats - should not be fed any dry food.  My Feeding Your Cat article explains why.  The carbohydrate content of dry Wellness Super5Mix is 28 percent.  This product's ingredients are far superior to the Hill's and Purina dry food choices but no cat - and especially a cat with diabetes - should be consuming a diet with 28 percent carbs regardless of the ingredients.

Switching the Diabetic Cat to a Low Carbohydrate Diet

Caution:  This must be done very carefully.  See above if you have not already read the Critical Points section.

The safest way to implement a diet change is to incorporate home testing into your management protocol.  

You need to also discuss any diet change with your veterinarian but be aware that many vets underestimate the degree to which the insulin dosage needs to be lowered when a low carb diet is implemented - which puts the patient in great danger.

For example, let's consider a cat that is currently eating Hill's Science Diet dry w/d with 37 percent of its calories coming from carbs and he is suddenly switched to canned Wellness at 3-5 percent carbs.  If the insulin is not lowered accordingly, an overdose of insulin will occur.  Please do not underestimate the favorable impact that a low carb diet has on decreasing the BG level of a cat. As stated at the beginning of this page, many cats no longer need any insulin once on a low carb diet.  Others have a drastic decrease in the amount of insulin needed to maintain an optimal BG level.

The goal is to get your cat off of dry food and on to a 100 percent canned food diet but this must be done carefully - especially if the cat refuses to eat canned food.

Giving a full dose of insulin to a cat that is not eating can result in life-threatening hypoglycemia.

Many of the tips that I offer in the Transitioning Dry Food Addicts to Canned Food section of my Feeding Your Cat article can be used for diabetic cats but please be cautious as you implement them if you are also injecting insulin.

A non-diabetic cat can very safely handle the 'tough love' 12-18 hours period of time without food that is often necessary to get them to change their diet but this does not apply to a diabetic patient, therefore switching a stubborn diabetic cat can be more difficult.  It is not impossible but the process does have some complicating factors.

With a stubborn cat that is a dry food addict, approach the diet transition slowly and with patience.  For cats that like canned food but are still eating a 100% dry food diet, the transition can proceed much more rapidly (within 7-10 days) as long as the blood glucose is being monitored and the insulin is being adequately adjusted downward.  I cannot stress this last point strongly enough.

Truth be told, I would switch the cats that are willing to eat canned food faster than 7-10 days but you can error on the side of caution and go slower than I would if you are more comfortable doing so.

With regard to the issue of diarrhea and a diet change - I don't mind a bit of loose stools (tooth paste +/- with a bit of pancake batter-consistency) and tend to just keep on with the canned food diet.  These loose stools often firm up within a few weeks on the new diet.

For cats that are eating some canned and some dry, I would go 'cold turkey' and pull the dry food now - as long as the insulin is adjusted accordingly.

Please see this thread on the Feline Diabetes Message Board to read about many caregivers' success with their diabetic cats once all dry food was removed from the diet.

In-Home Blood Glucose Monitoring

A human with diabetes would never dream of trying to mange his disease without the use of a glucometer ("meter") to test his blood glucose level prior to injecting insulin.  It is simply not safe to inject insulin blindly - into a human or a cat.

If you do not fully appreciate the need to keep your diabetic cat safe with home testing, please check out this link on the Feline Diabetes Message Board.  It is an informal collection of comments from diabetic cat caregivers outlining the dangers of shooting insulin blindly - without testing first.  Blood sugar levels change hour-to-hour in all living creatures but they can be even more erratic in diabetics.  Shooting a set amount of insulin every 12 hours is simply done for the convenience of the cat owner but it is not necessarily a physiologically sound way to handle this disease.

Meters, test strips, lancets, lancet pens:

The meters that are used by humans can also be used to successfully monitor a diabetic cat.

You do not need a meter designed especially for pets such as the AlphaTrak which costs ~$100. 

If you or your veterinarian need some convincing that home blood glucose monitoring is critical to the optimal management of feline diabetes, here is a list put together by a member of the Feline Diabetes Message Board of many veterinary and PubMed articles discussing the value and validity of blood glucose monitoring of cats.

Two veterinary journal articles can  be found here and here that verify the accuracy of these meters for use in diabetic pets.

Sadly, many of my colleagues either do not introduce their clients to this life-saving tool or, worse yet, dissuade their clients from the practice of home monitoring.  This lack of pro-active management has resulted in the death of many cats and the less-than-optimal management of countless others.

There are many meter models to choose from.  You can often get the meters for free (or around $10) when you purchase 50 - 100 strips since the manufacturers want to get you locked into buying their strips.  (Think cheap printer prices - they are cheap because the companies want to get you locked into buying their expensive ink cartridges.)

Hocks is a good place to buy meters and strips online. 

Ebay is also a good place to buy strips but watch the expiration dates.

There are two important factors to consider when buying a meter:

1) cost of strips

2) amount of blood needed

An acceptable range of blood that is needed by these meters is .3 (that is 3/10 or 'point' 3) uL (microliters) to 1.0 uL.

On occasion, I will hear complaints from people saying that 1 uL of blood is hard to get from their cat's ears.  These people have an easier time with the meters that need either .6 or .3 uL.

The One Touch Ultra is a very good meter but the strips are more expensive than those of other meters so even though this meter is a favorite among the members of the Feline Diabetes Message Board in terms of ease of use and accuracy, some people comment that the strips are just too expensive.  The OTU requires 1 uL of blood.

Many people really like the TrueTrack meter and also the Walmart ReliOn.  The meters and their strips are cheap and the meters are accurate.  The TrueTrack, like the One Touch Ultra, also takes 1 uL of blood.  The Walmart ReliOn uses .6 uL of blood.

Other favorites include the Ascencia Contour (.6 uL), Accucheck Aviva (.6 uL), and the Freestyle (.3 uL), although the Freestyle has been reported to underestimate the blood glucose value in the higher ranges (>300 mg/dl).

It is important to get a meter that uses 'wicking' test strips which all of the above meters use.  These strips automatically draw the blood into the testing area as soon as the edge of the strip contacts the edge of the blood drop. This is in contrast to the type of meters that use strips requiring that the blood be dropped directly onto the test strip.

Lancets range in size from a large 25 gauge to a very small 33 gauge.  However, most companies do not state the gauge size on their lancet boxes so it can be confusing when trying to figure out which lancets to buy.  Generally speaking, when you see lancets labeled "ultra-fine" or "ultra thin", that denotes a very fine lancet size (31,32,33 gauge).  Exception to the word "ultra" is the LifeScan One Touch UltraSoft lancets.  They are 28 gauge and many people have good luck with those.

See this chart for lancet sizes.  Keep in mind that the lancet has nothing to do with the meter.  You do not have to use the same brand of meter and lancet.

The larger the number, the smaller the needle point.  The smaller the needle point, the harder it is to get enough blood but the more comfortable it will be for your cat so you can see that it is a trade-off. However, contrary to what you may think, most cats don't even feel the lancet stick.   I think they 'feel' the nervousness of the human even more!  What bothers them the most is the restraint and sometimes the noise of the lancet pen.

Most people like to use a lancet in the 28-29 gauge range especially when first starting out since it can be frustrating enough to get blood without having to deal with an ultra-fine lancet.

Some people like to use an even larger lancet (26 or 27 gauge).  They are happier with the blood flow and their cats don't seem to mind the larger size.  Other people have had great luck with the lancets that are much finer - more in the 31-33 gauge range.  It all depends on how good of a 'bleeder' your cat is.

You will have to experiment to see what size of lancet works best for you and your cat.

One example of the lancets that I have used is the Life Scan One Touch FinePoint Lancets (purple ones) which, according to the chart above, is a 25 gauge lancet. (No gauge number is listed on the box but I assume that the chart is accurate.)

I have also used the Life Scan One Touch UltraSoft Lancets  (white ones) which are 28 gauge.

The use of the FinePoint lancets will result in a large enough drop of blood more consistently than if you were to use the UltraSoft lancets.

Most meters come with 10 lancets but they vary in size depending on the company.  I notice that the One Touch Ultra kits come with the UltraSoft lancets which may - or may not - prove to be too frustrating when you are first starting out.  You can try them but if you are unable to get enough blood with the ultra-fine lancets, you will have to purchase some larger ones such as the OneTouch FinePoints.

Each meter kit should also come with a lancet device (lancet 'pen') that you can adjust to give a deeper or more shallow penetration of the lancet.  For instance, the One Touch Ultra meter comes with a lancet device that has 7 settings with the largest circle corresponding with a greater depth of penetration.  I found that setting it on the fifth setting (with the first setting being the smallest circle/less penetration) gave the most consistent results.  Setting it on the fourth also worked, but not as consistently.

Testing your cat:

The most common mistake that I see people make is that they do not hold the ear gently but firmly against the tip of the lancet pen.  Instead, they let the ear fall away from the pen.  If this happens, the lancet will not penetrate the ear.

Here is a pictorial webpage that demonstrates the testing procedure.  There is a nice picture on this page that shows where the vein is in the ear of the cat.  It runs just around the margin of the ear. You will find that there are several different opinions and techniques recommended for the testing procedure and, with time, you will figure out which ones work best for you and your cat.  For instance, this page shows the person approaching the cat head-on (in order to test the inside of the ear, versus the outside) which I find makes many cats nervous.  They tend to want to back away from the person and so I would much rather stay behind them as described below.  However, the author of this page points out that there is minimal hair on the inside of the cat's ear which may be an important consideration when testing a long-haired cat.  Long hair can interfere with the blood drop formation.  This page also discusses the use of warming devices for the ear and the optional use of Vaseline - neither of which I have found necessary.  However, I have not tested any long-haired cats and so the Vaseline may be of benefit in these cases.

Here is a movie  that  demonstrates the testing procedure.  This movie shows the operator using a lancet pen.

This second movie, located here, shows the operator using the lancet 'free-hand' - without the pen. 

A third movie is located here.  This movie shows the veterinarian using a 25 guage needle instead of a lancet.  I do not recommend this method.  A 25 guage needle is overkill and is larger than even the thickest lancet and produces an amount of blood that is much more than you need.

The first movie shows the demonstrator using a warmed rice sock that is applied to the ear. Some people like using this method (the warmth increases the blood flow to the ear) but I find it cumbersome and annoying to have to use one more item when testing a cat.  I do not apply anything warm to the cat's ear and find that the blood drop gathers just fine.  Sometimes, however, you will need to 'milk' the blood up to the punctured area for just a couple of seconds.  Be aware, however, that if you do not have anything against the inside of the ear other than your own finger, you may stick yourself especially if using a lancet pen versus free-hand.  As shown in the third movie, a small cotton ball or tissue can be used to protect your finger.

These movies show the patients being star pupils although Punkin's owner mentions that he was not this good at the beginning of the testing.  The cats in these movies are minimally restrained but, in reality, not all cats are this good about testing.  Most of them, however, do improve with time.

It is very important to be patient and move slowly and calmly.  Also, the best time to try this procedure for the first time is when your cat is sleepy.  Keep in mind that there is a learning curve for both of you and the less nervous you are, the better off both of you will be.  Rest assured that the procedure will most likely get easier as you polish your skills.

When first starting to test a new patient, I click the pen several times around the cat's ear to make sure he gets used to the noise before I poke him.

When first testing very skittish cats, I may even simply lightly restrain them and click the pen a few times - without poking them - and then feed them a treat and let them go.

Offering the cat his favorite treat in conjunction with the testing may help keep him calm and persuade him to view this procedure in a more positive light.

Baby steps and positive reinforcement (treats)......are often good ways to approach any type of training.

Although certainly not necessary, it may be easier on your nerves if the first test is done under supervision at your veterinarian's office.  You can also check in with the Feline Diabetes Message Board to see if there are any members living near you who can help you learn how to home test.  There are many wonderful members of this board who are spread all over the world and who are willing to help a 'newbie' learn how to home test. 

Everyone has their preference when it comes to methods used to handle their cat and every cat also has their own idea of what level of restraint they will tolerate.  The least amount of restraint that can be used to get the job done is obviously going to make this less stressful for both of you.  If you can test them, unrestrained, while they are just hanging out on their favorite chair, that is optimal.

Please note that in the following pictures the test strip should already be in the meter but I did not have any at the time these pictures were taken.

Testing Calvin's right ear with minimal          Testing Calvin's left ear with no

bracing of his head.                                  restraint.

The method that works best for me when testing a fidgety cat, is to kneel on the floor with the cat between my knees.  We are both facing the same direction and there is very little firm restraint involved. I just try to prevent the cat from going forward.  I am right handed so it is easiest for me to test the right ear but it is best for the cat to alternate between ears to keep one from getting too sore.  I use gentle pressure with my left hand on the left side of the cat's head to, hopefully, keep him from shaking his head while the blood drop is forming.  I hold the right ear with my left thumb and index finger and my right hand handles the lancet pen.  It is easiest for me to test the outside edge of the right ear but alternating between the inside and outside margins of each ear is optimal.  (Again, please note that the test strip should already be in the meter at this point.)

Testing Calvin's right ear with gentle       Testing Calvin's left ear while gently

restraint.                                            bracing his head.

The blood vessel runs along the margin of the ear. See here for a very good picture of the ear vein and a picture of a drop of blood forming after the poke.  Aim for the upper outer edge of the ear anywhere from half to three-quarters of the distance up the ear from the base toward the tip. 

A tricky issue to contend with is the cat's instinct to shake his head during those few critical seconds when you are waiting for the blood drop to form.

After the lancet is used, I lay it down but continue to gently hold onto the ear and keep a few fingers of my left hand on the left side of his head to prevent him from shaking off the forming drop of blood.  Of course, if he is allowed to do so, the drop of blood will go flying and you will have to start over again.  If a drop has not formed quickly, you can try to 'pump' the blood into the puncture area with your right hand.  This involves a gentle squeeze and release, squeeze and release just below the puncture site.  Another technique involves gently 'milking' the blood up the vein from the base of the ear.  This whole process takes about 5 seconds or less.

With the One Touch Ultra meter, you have 2 minutes to fill the test strip with blood once the strip is inserted into the meter so don't insert it too soon.  Insert the strip after the cat is in place and ready to be tested.  Two minutes is generally plenty of time but if the meter 'times out' simply remove the test strip and re-insert it.

The most common problem that I encountered when first starting to test cats with the glucometer was not getting the test strip confirmation window filled.  When this happens, the One Touch Ultra meter will read Er5 (error message) after the 5 second countdown.  You will then have to get a new strip and start again.  If the blood drop was too small and all of the blood has been drawn up by the test strip - but it is not enough - do not try to get more blood from the puncture site and reapply the test strip to the ear.  That will not work.  As soon as blood enters the strip, the meter starts counting down and adding more blood at this point is futile.

Also, do not try to 'scoop' or 'scrape' the blood off the ear and onto the test strip.  It must be draw up by the test strip via capillary action. 

Try to make a habit of watching the test strip window as you are touching the strip to the drop of blood. If your blood drop is large enough, this will ensure complete filling before taking the strip away and will result in a successful sampling.  With a bit of practice, you will also learn not to 'jump the gun' and apply the test strip before you have a large enough blood drop to fill the confirmation window.  If the drop looks too small, be patient and try to 'pump' or 'milk' the blood into the puncture area as discussed above.

After the test strip is filled, lay the meter down and gently hold off the puncture site with the cotton ball that you were using to protect your finger.  Necessary holding times will vary but usually 10 seconds or less will be sufficient.

Please be forewarned that you may want to cry and throw the meter when first attempting to test your cat's blood glucose!  There is a bit of a learning curve with this procedure - for both you and your cat - and the frustration level can be very high initially.  Take a deep breath, stay calm, keep a sense of humor, (drink a glass of wine...eat some chocolate......) and accept the fact that it may take you many tries at different times over the span of a few days to start consistently getting samples.  The calmer you are, the better off your cat will be.  Do not get discouraged if the first few times do not go well.  If success has not been met after 2-3 sticks (or if the cat is very nervous, after only 1 stick) feed him the treat you have standing by and let him go.  You can try again in a few hours.  You do not need to master this on the first try! 

As already mentioned, a group of very caring and knowledgeable people can be found on the Feline Diabetes Message Board.  They can often talk you down off of the 'ledge of frustration' that comes along with learning how to home-test and to interpret blood glucose curves.  These folks are not veterinarians but many of the members have a great deal of very practical experience in dealing with feline diabetes.

Managing a cat with diabetes can be very overwhelming, to say the least, and communicating with others who are faced with the same issues can be very helpful.  As with any online group, be sure to do your homework and conduct your own research, as well as listening to suggestions of other list members and staying in touch with your veterinarian.

Conclusion

While writing this webpage, I decided to see what information is available on the internet with respect to feline diabetes.  I was quite disturbed to see so many authors of the various websites, and posters in chat groups, still continuing to recommend a high complex carbohydrate/high fiber diet. A very critical point is being missed:  Cats are obligate carnivores and a high carbohydrate diet is detrimental to their health and will make the diabetic disease process worse. 

Also, high fiber diets run counter to a cat's natural diet and recent research has shown that high fiber diets, unlike what is observed in a diabetic dog or human, are not beneficial for a diabetic cat.

Fortunately, there has been a great deal of focus on feline diabetes in the past couple of years so when you are searching the internet, be absolutely sure to pay attention to the date on the webpage for the most recent information. 

The "Catkins" diet is in and the illogical high carbohydrate/high fiber diets are, thankfully, out.

For more information supporting the feeding of canned food versus dry kibble, see the October, 2005 edition of Cornell University's CatWatch newsletter.