As a feline practitioner, I often see the same client concerns repeatedly in our appointment schedule: not eating; vomiting; diarrhea; losing weight; hair loss; urinating around the house; etc. I never know ahead of time what the diagnosis might be. However, when I see “litter box is flooded” or “huge urine clumps in litter box,” one disease rises to the top of my list: feline diabetes.
Diabetes is the second most common glandular disorder in cats. (Hyperthyroidism is No. 1, if you were curious.) Diabetes occurs as a result of a problem with insulin, the hormone that controls blood glucose levels. Similar to humans, cats experience two types of diabetes. In Type 1 diabetes, the cat’s pancreas simply can’t make enough insulin. In Type 2 diabetes, the pancreas can make insulin, but secretion of insulin is impaired. This is coupled with “insulin resistance” — an improper response by the body to the insulin that the cat is making.
It is estimated that the majority (80 percent) of diabetic cats are Type 2 diabetics. This differs markedly from diabetes in dogs, all of which are Type 1. The fact that the majority of diabetic cats retain the ability to secrete insulin has exciting implications for treatment. As you’ll soon hear, it has been shown recently that tightly regulating the blood sugar with aggressive insulin therapy early in the course of treatment can cause many cats with diabetes to go into remission.
Although diabetes can strike at any age, it typically strikes middle-aged cats, usually around 7 to 9 years of age. Males are one-and-a-half times as likely to be affected. Obesity is another risk factor. In Australia, New Zealand and the U.K., Burmese cats are at higher risk. In the U.S., Maine Coon, Russian Blue and Siamese are predisposed.
The four classic signs of diabetes are increased thirst, excessive urination, ravenous appetite and weight loss. Owners will often remark that their cat is losing weight despite eating very well. Owners also complain that they need to change the litter much more frequently and that the urine clumps have become enormous (“the size of a cinderblock,” as one client once described it).
A few owners report wobbliness in the cat’s rear legs. This rear limb weakness is a condition called “diabetic neuropathy.” Affected cats exhibit a distinct posture, called a “plantigrade” stance, where they walk or stand on their hocks instead of their toes.
Diagnosis of diabetes is relatively straightforward. The presence of persistently elevated blood glucose in combination with excessive glucose in the urine is indicative of diabetes.
The focus of treatment used to simply be the amelioration of the clinical signs. Over the last few years, this has changed. New long-acting insulin preparations for humans have shown great efficacy in cats, in many cases resolving the diabetes completely. This “diabetic remission” has become the ideal goal — achieving normal blood glucose levels ultimately without the need for insulin. Exactly which cats go into remission depends on the type of insulin, the cat’s diet, how tightly the blood glucose is regulated, how early the treatment is initiated (the sooner the better), and whether the cat’s pancreas is able to secrete insulin (as with Type 2 diabetics).
Diet is an important component of therapy. Numerous studies have shown that the ideal diet for a diabetic cat is a high-protein, low-carbohydrate diet, with canned greatly preferred over dry. There are many prescription diets designed for this purpose, and nearly every veterinary office carries them. Some commercial brands (for example, some varieties of Fancy Feast) serendipitously have a nutritional profile appropriate for diabetics. Ask your veterinarian for recommendations, or conduct your own internet research. Insulin is the mainstay of therapy for diabetic cats. Both human and veterinary insulin preparations are available, and all of them work well; however, remission is more likely to be achieved with the newer long-
acting human insulin preparations such as glargine (brand name Lantus) and detemir (brand name Levemir).
Once insulin therapy has begun, blood glucose levels need to be frequently assessed, to determine whether the dosage needs to be adjusted. Too little, and the disorder will not be controlled. Too much, however, can cause life-threatening hypoglycemia (low blood glucose). Clearly, close monitoring is paramount, and this used to require frequent veterinary visits that were inconvenient for cat owners and very stressful for the cat.
Home monitoring of blood glucose, using meters specifically calibrated for cats and dogs (for example, the AlphaTrak), has become an excellent additional tool to improve long-term management of diabetes. Blood is obtained from the marginal ear vein that runs along the outer edge of the ear, and blood glucose is measured with the meter during the day. Cats tolerate this very well. Your veterinarian (or more likely, his veterinary technician) can demonstrate the technique in the veterinary office. Not every cat will achieve remission, and clients should be warned that some cats in remission may relapse at a later date. For those who don’t achieve remission, the goals of therapy remain the same as always: resolving the clinical signs of excessive thirst, urination and weight loss while avoiding complications such as hypoglycemia.
Achievement of remission is a huge advantage to both the cat owner and the cat, and is an exciting new frontier for veterinarians.
Thumbnail: Photography ©RyersonClark | Getty Images.
Dr. Arnold Plotnick is the founder of Manhattan Cat Specialists, a feline-exclusive veterinary practice on Manhattan’s upper west side. He is also an author of The Original Cat Fancy Cat Bible. Dr. Plotnick is a frequent contributor to feline publications and websites, including his own blog Cat Man Do. He lives in New York City with his cats, Mittens and Glitter.
Editor’s note: This article originally appeared in Catster magazine. Have you seen the new Catster print magazine in stores? Or in the waiting area of your vet’s office? Click here to subscribe to Catster and get the bimonthly magazine delivered to your home.