Cats and Carbs: An Update on Feline Diabetes

Monday, October 7, 2013 - 1:15pm
Large orange cat with yellow eyes

Guest blog by Louise Murray, DVM DACVIM, Vice President of the ASPCA Animal Hospital and author of “Vet Confidential: An Insider’s Guide to Protecting Your Pet’s Health”

Diabetes is a real problem for cats in this country, but the good news is that we now have a much better understanding of this condition, and even better, we can cure it in many cases. Best of all, we are learning how to prevent it, which is the ideal strategy for a healthy, happy cat.

Cause: It’s now believed that many cases of feline diabetes are caused by excess carbohydrates in the diet. Dry cat foods in particular can be high in carbohydrates. Cats are not designed to properly metabolize carbohydrates, and cats on dry food may become obese. Additionally, the excess of carbs forces the pancreas, the organ that produces insulin, to overwork. Over time, the pancreas can become exhausted, and lose the ability to make sufficient insulin. This lack of insulin causes diabetes.

Treatment: Most diabetic cats have not permanently lost the ability to produce insulin. In order to rest the pancreas and allow it to return to normal function, cats are given twice-daily insulin injections. It’s essential to carefully regulate diabetes so the cat receives the proper amount of insulin to restore the function of the pancreas while avoiding low blood sugar, a potential side effect of insulin treatment.  

The second essential component of treatment is the cat’s diet. For the best chance of curing diabetes, most cats should eat a canned diet formulated for diabetes, or a canned kitten food. Be sure to consult with your veterinarian regarding the best diet for your own cat.

A note of caution: Cats who refuse to eat can become very ill. Any diet changes must be made cautiously, with careful monitoring of the appetite.

For optimal treatment of diabetic cats, it may be advisable to consult with a veterinary internal medicine specialist. We have two on staff at the ASPCA Animal Hospital: Dr. Pomrantz and Dr. Frank. To find a veterinary internist in your local area go to

Prevention:  We all know that “an ounce of prevention is worth a pound of cure.” For diabetes prevention as well as urinary tract and digestive health, we advise feeding cats canned food in meals, rather than allowing them to graze on dry food. Just remember that when attempting to make any change in a cat’s diet, such as from dry to canned food, patience and caution are essential. Never allow a cat to “hunger strike,” which can cause serious illness.

For more information about keeping kitty healthy, or to make an appointment for your pet, please visit the ASPCA Animal Hospital.




There are a number of companies that make grain-free dry food (EVO, Wellness, Blue Buffalo), but no dry food (that is, food that is bound into kibble) is carbohydrate-free, I believe. That's because they need some carb-based medium to bind it into kibble. Wet food, or freeze-dried raw (Primal, Wysong, etc.) is the gold standard. It's a myth that dry is better for teeth. The kibble is too small to do any work scraping off the plaque - they just crack it open and swallow it. Use any dental products (anti-plaque spray, dental treats, etc.), but brushing is best. You don't have to do it twice a day, even twice a week is better than nothing. If you do it right, your cat may actually enjoy it. Mine asks to get her teeth brushed!
Any time you switch your cat from one type of food to another, you HAVE to do it gradually. Add small amounts of new food into old, then increase the percentage over a week or two until it's all new. This is critical, or else you cause stomach upset or worse. Besides, no cat that's been eating one kind of food all his life is going to just take to another overnight.
Best not to experiment making your own food, unless you're an animal nutritionist, or like to gamble with your pet's health.

ashley oliver

My vet (a Board Certified Feline Practitioner) told me years ago that the dry food was was causing the epidemic of diabetes and obesity. Now we have the answer--GRAIN FREE dry foods, good quality ones that are not loaded with potato for cheap filler (sweets and yams are fine)--read the ingredients: meat, low glycemic veggies and fruits (like berries), NO rice, barley, wheat, soy,oatmeal, or grain of any kind, and your kitty will be eating well. They are more expensive to buy but end up costing about the same since kitty will eat less because they are nutrient rich (the difference between feeding a steak and a loaf of white bread) and you'll save on vet bills.Gotta go to a good pet stores not the local market--well worth it.


Any good grain free dry food recommendations?

Denise Neal

I found out that my rescue cat had diabetes when I had her blood sugar tested (she was an old girl and nobody wanted to adopt her except ME). She was obese, sluggish/inactive, dull/course dandruff fur and drank an enormous amount of water. I couldn't afford the insulin shots so I started mixing one teaspoon of powdered organic brewers yeast (Lewis Lab or Twinlabs brand) in her soft food. She has now lost considerable weight and is much more active and alert, soft shiny dandruff-free coat, and drinks less water. I truly believe the brewers yeast nutritional value (vitamins, minerals, chromium) is probably helping tp keep her blood sugar more regulated. I also limit the amount of dry food and buy only grain-free. Will see what the Vet says on next checkup visit.


I have a nine year old Neutered male cat who was diagnosed with diabetes this summer. I have spent so much money on vet bills (over $2,000) trying to get his blood sugar regulated. He weighed 17 pounds at the time he was diagnosed, he was not fat he is just a very big kitty. He now weighs 13-1/2 pounds and is receiving 5-1/2 units of insulin twice a day. He still drinks a lot of water, urinates way too much (I have to change his litter box 3-4 times a day) and he sometimes pees on the floor, furniture or what ever he wants to. I changed his moist food to Fancy Feast Classic and a little Fancy Feast dry food.

Where did you find the organic brewers yeast? I have to try something else because I just retired and my income has decreased substantially. What kind of grain free food do you feed you little girl? I need all the help and suggestions I can get. Thank you


Can you tell me how many ounces of can food should I feed my cat if I want to switch and how many times per day (if more than once?) Thank you!


Check the can for feeding instructions, it recommends the weight for the amount to feed them.


A wonderful food for cats with Diabetes is a raw food diet. If you can afford it, you can buy ready made frozen versions (brands like Natures Variety make a wonderful frozen raw food). Raw food has less than 5% carbohydrates, compared to dry cat foods 40-50% carbohydrates. If you cant afford to buy the ready made stuff, but you have free time, pick up a book like Dr. Becker's Real Food for Healthy Cats and Dogs. Or Dr. Ian Billinghursts BARF Diet (bones and raw food). These teach you how to make a completely balanced raw food diet at home!
You could also go 50-50. 50% Raw frozen diet, and 50% canned wet food.

Julie Anderson

My cat was diagnosed with diabetes and put on insulin. We did some research and learned of the high carb connection and transitioned her to a low carb diet of the canned pate type food. Within 3 weeks of diagnosis, she was completely off insulin and has remained that way for 10 mos so far. If your cat is currently on insulin, and you want to change its diet, it's VERY IMPORTANT to consult with your vet first to work on a strategy to reduce their insulin. When you reduce the carbs in the diet they will need far less insulin and you don't want them to have a hyoglycemic event which can easily lead to death. We monitor her glucose at home with a meter and check the carb content and ingredients of any wet food we give her; foods with gravy all have too much carb, the pate ground foods are mostly ok. There is now a "Zero carb" dry food for cats from a specialty manufacturer and we have used this successfully to supplement the wet pate food.

Julie Anderson

I want to ad that the food we feed her is mostly the 12 flavors of Fancy Feast Classics--these are the small cans with the pate type food that say "Classic" along the bottom of the label...the "Grilled" or "Elegant Medleys" or "Sliced", "Grilled", "Gravy Lovers", "Marinated Morsels" or "Mornings" are NOT SUITABLE for managing diabetes. We also feed Friskies pate foods. The Zero Carb dry cat food I'm referring to is made by, you can find it from web search. I feed 3-4 small wet meals a day (1.5-2oz)and leave out a couple Tablespoons of dry for her to graze on so she doesn't have to process big meals which might spike her insulin. Now that she is off insulin and on this diet I test her insulin at home 2-3 mornings per week, very easy once you get the hang of it. The website that helped me most with this was Their message board is excellent and full of people willing to help you get your cat regulated and hopefully off insulin. They also will point you to lists of commercial cat foods that are low carb and suitable for helping managing diabetes. Raw food is nice if you are ambitious, but there are economical commercial solutions which might be more convenient for you -- you don't have to buy special pricey "diabetic" food from your vet (which often is high carb!)