Feline diabetes beliefs

I’ve worked with nine diabetic cats now – one of my own that was diagnosed after I adopted her (and responsible for teaching me so much), four adopted diabetics, and four fosters. Five were able to be “diet-controlled” (no requirement for insulin), the other four need/needed small doses of insulin along with an appropriate diet. (Two or three of those four had temporary bouts of remission.) As many caregivers ask my thoughts on feline diabetes, I thought I’d summarize my “personal beliefs” as they presently stand regarding effective treatment. I am always studying and learning new things when it comes to diabetes mellitus, so I expect as I learn more I’ll fine-tune my beliefs further.

* Low carbohydrate WET diets are ideal. Studies show 60% to 80% of diabetic cats may stop needing insulin once switched to a low-carbohydrate WET diet. (As far as I know, there are no studies showing low-carbohydrate diets to be as effective, and anectdotal evidence shows them to be much LESS effective.) Prescription diets aren’t necessary, just find a canned or raw diet with little-to-no grains, vegetables, or fruit. Readily available canned foods like Fancy Feast gourmet feast, 9-Lives ground dinners, Friskies, Evo 95% meat, etc. generally work fine. Avoid the foods in gravy if possible, they generally contain starches or syrups.

* Longer-acting insulins (such as PZI, Lantus/Glargine, or Levemir) are best. These insulins have longer durations and later NADIRs (peaks) than shorter-acting insulins (such as Humulin N or Vetsulin/Caninsulin). By the way – PZI-Vet by Idexx is no longer in production, however compounded beef/pork PZI is still available from sources such as BCP and VPA. BCP will send your veterinarian a free sample vial of PZI upon request.

* Home-testing blood sugar levels enables best management of diabetes. There’s a reason human diabetics are urged to home test! Human monitors are fine and may be purchased at any drugstore. The special veterinary meters are more expensive, and their test strips are more pricey and harder to obtain. I’ve personally tested the special vet meter against my own “human” meter and the differences were insignificant. Meters aren’t designed to be 100% accurate and that’s OKAY! People still use them, with good reason. They tell you if blood sugar levels are high or low, and enable you to see trends.

* Obesity does not cause diabetes. However, both obesity and diabetes are risks of a high-carbohydrate, particularly a high-carbohydrate DRY (kibble) diet.

* Lower fat diets are not always necessary for pancreatitis. While some caregivers of cats with pancreatitis feel their cats are more comfortable on a lower-fat diet, there’s no scientific evidence that shows cats with pancreatitis benefit from less fat in their diet (unlike humans or dogs). Personally, the cats I’ve worked with that have had pancreatitis may have had reactions to grains, vegetables, or fruit, but not fat. If lowering fat intake, by necessity protein or carbohydrates must increase. I personally feel *no* cat, especially a cat with pancreatic conditions, benefits from increased carbohydrate intake.

* Many, if not most, diabetic cats have pancreatitis. Pancreatitis is very difficult to diagnose. While recent advances have led to blood tests that assist in diagnosis, the “gold standard” remains an invasive biopsy or necroscopy. Best estimates are that 60% or more of diabetic cats have concurrent pancreatitis. It’s unknown whether pancreatitis led to diabetes, diabetes leads to pancreatitis, or if they just both occur concurrently due to the same (but unknown) cause – like obesity and diabetes often both occur as they may both be caused by high-carbohydrate diets.

* Glucose (syrup, honey, etc.) or high-carbohydrate dry food given at low blood glucose levels can be counterproductive, and could even be dangerous. None of my cats have exhibited clinical symptoms at lower-than-normal blood glucose readings (and I’ve caught them so low the meter can’t read it, under 20). However, at low blood sugar levels I generally give them a low-carbohydrate raw or canned snack. Giving a dry food or glucose will likely send blood sugars rocketing up, then crashing back down afterward. (Think of how your body reacts when you eat a candy bar or other sugary snack – boost of energy, then crash.) Studies have shown that cats experiencing hypoglycemia were LESS likely to suffer brain damage if they were NOT given glucose, even if they experienced seizures.

* Dry (kibble) foods increase risks of hyperglycemia and hypoglycemia (”hypo” or insulin shock). Not only does dry food (even “low-carbohydrate” dry food) immediately raise blood sugar levels due to its high carbohydrate content and high glycemic index, but carbohydrates raise blood sugar levels quickly, then wear off quickly – putting the body on a roller coaster ride of high to low blood glucose levels. (Think of how you feel after a carbohydrate-ridden snack or meal.) Also, should the cat refuse to eat or vomit, blood sugar levels can plummet and/or be drastically lower than typical – and you can’t “take back” any insulin you’ve injected.

* Tight regulation, or as close as you can manage, is best. High blood glucose levels can shorter-term cause diabetic ketoacidosis, which is life-threatening. Longer-term it can cause damage to the kidneys, heart, and other organs.

* Insulin given at low blood sugar levels may be counterproductive. Introducing exogeneous insulin when blood sugar levels are perceived as normal by the body may stimulate the liver to release glucose stores – in a process like Somogyi rebound.

* Micromanagement isn’t productive. While I use a sliding scale, adjusting dose based on blood sugar llevels, I generally don’t adjust that scale more often than every three days or so. (More often in the beginning as I figure out how the cat responds, less often after they’re stabilized.) I generally test blood sugar levels at least three times daily in the beginning (before each shot and a spot check in between to see how low they are dropping), and perform curves, testing every two or three hours between shots, every week or two in the first months they’re on insulin (if they’re on insulin that long). Once stabilized, I still test before each shot and do occasional spot checks. Once off insulin, I may test twice daily for a month or two, then once daily, then less often. (My Jellybean has been off insulin almost two years now, and I only test her blood sugar levels every few months. Same for Ralph, who’s been a “diet-controlled diabetic” since 2004.)

For more information, visit Feline Outreach – Diabetes Education.

References:

Feline Diabetes Mellitus – Antech News, Dec 2003

Evaluation of long-term home monitoring of blood glucose concentrations in cats with diabetes mellitus: 26 cases (1999–2002)

Capillary blood collection valuable tool in at-home diabetes management

Understanding feline diabetes mellitus Drs. Rand and Marshall

Canine and Feline Diabetes Mellitus: Nature or Nurture? Dr Rand et al

Update on Feline Diabetes Mellitus by Claudia E. Reusch, DECVIM-CA, Clinic for Small Animal Internal Medicine, University of Zuerich, Zuerich. World Small Animal Veterinary Congress (WSAVA) 2006.

Feline Diabetes Mellitus by David Church. WSAVA 2006

Hypoglycemic Brain Injury: Potentiation From Respiratory Depression and Injury Aggravation From Hyperglycemic Treatment Overshoots

Feline Pancreatitis by Jorg Steiner (WSAVA 2001)

Feline Pancreatitis: Underdiagnosed and Overlooked Margie Scherk, DVM, DABVP (WSAVA 2003)

Update on the Diagnosis and Management of Feline Pancreatic Disease by Stanley L. Marks, BVSc, PhD, DACVIM, DACVN (Waltham Feline Medicine Symposium, 2003)