What Is Feline Diabetes?
Diabetes mellitus is a metabolic disorder characterized by persistently elevated blood glucose levels resulting from inadequate insulin production, impaired insulin action, or both. In cats, the vast majority of cases are type 2 diabetes, where tissues become resistant to insulin’s effects, eventually causing beta cell exhaustion and declining insulin secretion. A small proportion of cases are type 1 or secondary to medications or other diseases.
Feline diabetes is increasingly prevalent — between 0.5% and 2% of domestic cats are affected, a rate that has risen alongside feline obesity. Remarkably, some cats achieve diabetic remission — a return to normal glucose regulation without ongoing insulin therapy — when disease is caught early and managed aggressively. This possibility makes early diagnosis and committed management especially important.
Risk Factors and Causes
Obesity is the single most significant modifiable risk factor — overweight cats are four times more likely to develop diabetes than lean cats. Excess adipose tissue releases inflammatory cytokines that interfere with insulin receptor function, reducing glucose uptake by cells. Physical inactivity compounds this risk, making indoor sedentary cats particularly vulnerable.
Age plays a role — middle-aged to older cats (7+ years) are most commonly diagnosed. Male cats are diagnosed at roughly twice the rate of females. Burmese cats show a genetic predisposition. Prolonged use of corticosteroids (prescribed for asthma, inflammatory bowel disease, and allergies) is a significant cause of secondary diabetes, as glucocorticoids directly oppose insulin action. Acromegaly — caused by a growth hormone-secreting pituitary tumor — is an underdiagnosed cause of insulin-resistant diabetes in cats.
Recognizing the Symptoms
The classic clinical signs are polyuria (frequent large-volume urination), polydipsia (excessive drinking), and unexplained weight loss despite a normal or increased appetite. Owners may notice the litter box filling more rapidly, water bowl emptying faster than usual, and the cat losing muscle mass while eating well — this combination is highly suggestive of diabetes.
As disease progresses without treatment, cats may develop diabetic neuropathy — weakness of the hindlimbs causing a plantigrade stance (walking on the hocks rather than the paws). This is often reversible with good glucose control. Severely uncontrolled diabetics can develop diabetic ketoacidosis (DKA), a life-threatening emergency characterized by vomiting, lethargy, complete loss of appetite, and a distinctive sweet or acetone-like odor to the breath.
Diagnosis and Monitoring
Diagnosis requires persistent hyperglycemia alongside glucosuria (glucose in the urine). A single blood glucose reading is insufficient because cats notoriously develop stress hyperglycemia during veterinary visits — glucose can nearly double from anxiety alone. Fructosamine (average glucose over the preceding 2–3 weeks) provides more reliable assessment and is an important diagnostic and monitoring tool.
Once diagnosed, monitoring is an ongoing commitment. Many owners learn to check blood glucose at home using a glucometer calibrated for cats, which reduces stress hyperglycemia artifacts and provides data from the cat’s normal environment. Freestyle Libre continuous glucose monitoring patches are used in some cats for unprecedented data density. Regular fructosamine checks and urine tests at the veterinary clinic complement home monitoring.
Treatment: Insulin, Diet, and Lifestyle
Most diabetic cats require insulin injections, typically given twice daily with meals. Cats are most commonly treated with Glargine (Lantus) or Detemir (Levemir) — long-acting insulin analogs associated with the highest remission rates when combined with a low-carbohydrate diet. Doses are adjusted based on glucose curves (serial glucose readings over 12–24 hours) until stable regulation is achieved.
Diet is critically important. Cats are obligate carnivores poorly suited to high-carbohydrate diets, yet most dry cat foods contain 30–50% carbohydrates. Switching to high-protein, low-carbohydrate wet food dramatically reduces post-meal glucose spikes and insulin requirements. Many cats achieve remission within weeks to months of dietary change combined with appropriate insulin therapy. Weight loss in obese diabetic cats should be pursued gradually — rapid weight loss risks hepatic lipidosis (fatty liver disease). Interactive play exercise also improves insulin sensitivity over time.