Diabetes in Cats: Symptoms, Diagnosis & Daily Management

Diabetes mellitus is a failure of insulin — the hormone that moves glucose from blood into cells. Without enough insulin, glucose accumulates in the bloodstream while cells starve for energy. The body breaks down fat and muscle, causing weight loss despite eating.

Feline diabetes resembles type 2 diabetes in people. Obesity, physical inactivity, and high-carbohydrate diets are major risk factors. Burmese cats may have a genetic predisposition.

Classic signs include:

• Polyuria and polydipsia — urinating and drinking more than usual
• Weight loss — despite normal or increased appetite (polyphagia)
• Lethargy and reduced grooming
• Plantigrade stance — weakness in hind legs, walking on the hocks due to diabetic neuropathy
• Recurrent infections — urinary tract infections are common

Diabetic ketoacidosis (DKA) is an emergency — vomiting, rapid breathing, sweet-smelling breath, collapse, and coma. Untreated or poorly controlled diabetes can progress to DKA quickly.

Your vet diagnoses diabetes with blood glucose and fructosamine testing, plus urinalysis showing glucose and sometimes ketones in urine. Persistent hyperglycaemia with clinical signs confirms the diagnosis.

Pancreatitis, hyperthyroidism, and kidney disease can affect glucose — your vet may run a full senior panel to identify concurrent conditions.

Insulin therapy

Most diabetic cats require twice-daily insulin injections — commonly glargine (Lantus) or protamine zinc insulin (ProZinc). Your vet demonstrates injection technique using small needles under the skin. Insulin must be given consistently at the same times daily, paired with meals.

Never adjust insulin dose without veterinary guidance. Too much insulin causes hypoglycaemia — weakness, seizures, and collapse.

Diet

A high-protein, low-carbohydrate canned diet improves glucose control and supports remission. Consistency matters — feed the same food at the same times relative to insulin injections. Dry kibble is generally avoided due to high carbohydrate content.

Weight management

Obese cats should lose weight gradually under vet supervision. Weight loss improves insulin sensitivity and is the strongest predictor of remission.

Monitoring

Home glucose curves or continuous glucose monitors help your vet adjust insulin dose. Watch for signs of low blood sugar — wobbliness, seizures — and keep corn syrup or honey accessible for emergency oral glucose as your vet advises.

Up to half of newly diagnosed cats — especially those started on insulin promptly and fed appropriately — enter diabetic remission, no longer needing injections. Remission is not guaranteed permanent; weight and diet must be maintained lifelong to reduce relapse risk.