Type 1 and Type 2 Diabetes in Cats

1 Feline Diabetes: Types, Signs, and Treatment

1. Causes of cat diabetes

The main factors are obesity, infection, concurrent disease, drug irritation, pancreatitis, and possibly heredity.

2. Clinical signs

The signs mirror dog diabetes: heavy drinking, frequent urination, and weight loss. Others include sleepiness, withdrawal from the owner, less grooming, a dry coarse dull coat, less jumping, and weak hind legs. A normal cat’s blood glucose is about 80–120 mg/dl; stress can push it to 300–400 mg/dl, but that alone is not diabetes. If glucose is high yet glycated hemoglobin and fructosamine are normal, it is also not diabetes. Beyond the symptoms, a diabetic cat shows persistent high blood sugar and sugar in the urine when fasting.

3. Treatment

1) For type 2 diabetes — high blood sugar but no urine ketones and otherwise fairly healthy — oral hypoglycemic drugs can be used. Common ones are glipizide (2.5 mg by mouth twice a day) and glibenclamide (0.625 mg by mouth once a day), for two weeks. If there are no side effects or hypoglycemia, continue. If glucose won’t drop and ketones appear, switch to insulin.

2) Insulin injections: early on, glargine or protamine zinc insulin works best, 1–2 units twice a day, and switch the cat to a diabetic prescription diet. If glucose stays high, the insulin may not be working or the cat may be resistant. Cats are sensitive to insulin, so after the first day aim to keep glucose at 90–270 mg/dl, then maintain insulin long term and adjust the dose as needed. Dosing must be exact — too much or too little harms the cat, and an overdose can cause hypoglycemia, seizures, even death.

Most of this treatment is carried out by the vet; the aim is simply to help owners understand feline diabetes so they can manage the cat’s diet and not feel helpless when it happens.