Diabetes mellitus is one of the most common endocrine disorders in cats, affecting an estimated 1 in 100 to 1 in 200 cats. Unlike dogs, who almost always develop Type 1 (insulin-dependent) diabetes, the majority of diabetic cats have Type 2 diabetes, which involves insulin resistance combined with progressive beta-cell dysfunction. This distinction is clinically important because many diabetic cats can achieve diabetic remission — a state in which insulin injections are no longer needed — with early, aggressive treatment and dietary management. Consult your veterinarian for proper diagnosis and an individualized treatment plan.
Overview
In healthy cats, the pancreas produces insulin, which allows glucose to enter cells for energy. In Type 2 diabetes, cells become resistant to insulin’s effects, and the pancreas eventually cannot produce enough insulin to compensate. Risk factors for feline diabetes include:
- Obesity — The single most important risk factor. Obese cats are 3 to 5 times more likely to develop diabetes.
- Age — Most commonly diagnosed in cats over 7 years of age.
- Sex — Male cats, particularly neutered males, are at higher risk.
- Physical inactivity — Indoor-only, sedentary cats are at increased risk.
- Corticosteroid use — Long-term steroid therapy (oral or injectable) can induce or worsen diabetes.
- Breed — Burmese cats have a documented genetic predisposition in some countries.
Symptoms
Classic signs of feline diabetes include:
- Increased thirst (polydipsia)
- Increased urination (polyuria) — owners may notice heavier, wetter litter clumps
- Increased appetite (polyphagia) despite weight loss
- Weight loss, particularly muscle wasting along the spine
- Lethargy and decreased activity
- Unkempt or oily coat (diabetic cats often stop grooming effectively)
- Plantigrade stance (walking flat on the hocks rather than on the toes) — indicates diabetic neuropathy
If your cat shows a combination of increased thirst, urination, and weight loss, schedule a veterinary appointment promptly. Untreated diabetes can progress to diabetic ketoacidosis (DKA), a life-threatening emergency characterized by vomiting, dehydration, lethargy, and a distinctive sweet or acetone-like breath odor.
Diagnosis
- Blood glucose — Persistently elevated blood glucose (hyperglycemia). Note: stress hyperglycemia is very common in cats during veterinary visits, so a single elevated glucose does not confirm diabetes.
- Fructosamine — Reflects average blood glucose over the preceding 2 to 3 weeks, helping distinguish true diabetes from stress hyperglycemia. Elevated fructosamine supports a diabetes diagnosis.
- Urinalysis — Presence of glucose in the urine (glucosuria). Healthy cats do not spill glucose into urine. Urine may also be checked for ketones.
- Complete blood work — Assesses for concurrent conditions such as kidney disease, pancreatitis, and hyperthyroidism, which are common in older cats and can complicate diabetes management.
Treatment & Medications
The goals of treatment are to resolve clinical signs, achieve good glycemic control, avoid hypoglycemia, and pursue diabetic remission when possible.
Insulin Therapy
| Insulin | Type | Key Notes |
|---|---|---|
| Insulin Glargine (Lantus) | Long-acting analog | Preferred by many feline internists due to higher remission rates when initiated early. Given twice daily by subcutaneous injection. |
| ProZinc (protamine zinc insulin) | Intermediate-acting, FDA-approved for cats | Veterinary-specific product. Given twice daily. Good option with established safety data in cats. |
| Vetsulin (porcine lente insulin) | Intermediate-acting | Less commonly used in cats than in dogs; shorter duration of action in many cats. |
Oral Hypoglycemics
| Medication | Notes |
|---|---|
| Bexacat (bexagliflozin) | SGLT2 inhibitor approved for use in cats that are not previously insulin-treated and are still eating. Promotes glucose excretion in urine. Not appropriate for cats with DKA, pancreatitis, or significant concurrent illness. Requires careful monitoring for euglycemic DKA. |
Dietary Management
Diet is a critical component of feline diabetes management:
- High-protein, low-carbohydrate diet — Mimics the cat’s natural carnivorous diet and significantly improves glycemic control. Many commercial canned foods are lower in carbohydrates than dry food.
- Canned (wet) food — Generally preferred over dry kibble due to lower carbohydrate content and higher moisture.
- Prescription diabetic diets — Available from major veterinary diet manufacturers (e.g., Hill’s m/d, Royal Canin Glycobalance, Purina DM).
- Weight management — Gradual, controlled weight loss for overweight cats improves insulin sensitivity.
Home Monitoring
Many veterinarians encourage home blood glucose monitoring using a handheld glucometer and ear-prick technique. Home monitoring can:
- Detect hypoglycemia early
- Generate blood glucose curves in a stress-free environment (more accurate than in-clinic curves for many cats)
- Help guide insulin dose adjustments in consultation with your veterinarian
Monitoring
- Blood glucose curves — Periodic measurement of blood glucose every 2 hours over a 12-hour period to assess insulin effectiveness and duration. May be done at home or in the clinic.
- Fructosamine — Rechecked every 2 to 4 weeks during dose adjustments, then every 3 to 6 months once stable.
- Clinical signs — Track water intake, urination, weight, appetite, and activity level.
- Watch for hypoglycemia — Signs include wobbling, disorientation, trembling, seizures, or loss of consciousness. If you suspect hypoglycemia, offer food immediately and contact your veterinarian. Rub corn syrup or honey on the gums if your cat is unresponsive.
Diabetic Remission
Diabetic remission — where the cat maintains normal blood glucose without insulin — is achievable in an estimated 25 to 50% of cats, particularly when:
- Insulin therapy is initiated early and aggressively
- A high-protein, low-carbohydrate diet is strictly followed
- Weight loss is achieved in overweight cats
- Underlying causes of insulin resistance (such as corticosteroid use) are eliminated
- Insulin glargine is used (associated with higher remission rates in some studies)
Remission is more likely in the first 6 months of treatment. Cats in remission should continue to be monitored periodically, as relapse can occur.
Prognosis
With dedicated owner commitment to treatment and monitoring, many diabetic cats live comfortably for years. Prognosis is influenced by:
- Early diagnosis and treatment — Increases the chance of remission
- Owner compliance — Twice-daily insulin injections and dietary management require commitment
- Concurrent diseases — Conditions like pancreatitis, kidney disease, or hyperthyroidism can complicate management
- Diabetic ketoacidosis (DKA) — A serious complication requiring emergency hospitalization; carries a guarded prognosis but many cats recover
Frequently Asked Questions
Can feline diabetes be cured? Many cats achieve diabetic remission with early, aggressive insulin therapy and dietary changes, effectively going off insulin. However, remission is not guaranteed, and some cats may relapse. Lifelong dietary management and monitoring remain important.
How do I give my cat insulin injections? Your veterinary team will teach you the proper injection technique. Insulin is given subcutaneously (under the skin), typically in the scruff or along the side of the body. Most cats tolerate injections very well, especially when given during meals.
Is dry food bad for diabetic cats? Most dry cat foods are significantly higher in carbohydrates than canned foods. Transitioning to a high-protein, low-carbohydrate canned diet is a standard recommendation for diabetic cats. Discuss specific diet choices with your veterinarian.
What if I accidentally give too much insulin? Insulin overdose can cause life-threatening hypoglycemia. If you suspect an overdose, offer food immediately and contact your veterinarian or an emergency clinic. Always have corn syrup or honey available at home as an emergency glucose source.
My cat was just diagnosed — should I start insulin or try diet changes first? Most veterinary internists recommend starting insulin therapy promptly alongside dietary changes, as early insulin treatment is associated with higher remission rates. Delaying insulin while trying diet alone may allow further beta-cell damage. Your veterinarian will advise based on your cat’s specific situation.