Feline diabetes (diabetes mellitus) occurs when a cat’s body cannot produce enough insulin or cannot use it effectively, leading to dangerously high blood sugar levels. It most commonly affects overweight, middle-aged to older cats. Unlike in dogs, a significant proportion of diabetic cats can achieve remission — meaning they may eventually no longer need insulin — particularly with early diagnosis, appropriate treatment, and dietary management.
Signs & Symptoms
- Increased drinking and urination — the most common early sign
- Weight loss despite increased appetite
- Lethargy, reduced activity
- Poor coat condition
- Hind leg weakness (plantigrade stance) — walking flat on the hocks. This indicates nerve damage from prolonged high blood sugar
- Vomiting (may indicate diabetic ketoacidosis — a veterinary emergency)
- Sweet or fruity breath (ketoacidosis)
Insulin Treatment
- Most cats require insulin injections twice daily, given under the skin (subcutaneous)
- Caninsulin is the most commonly prescribed veterinary insulin in the UK — 10ml vial costs approximately £33–43
- Owners learn to inject at home — most cats tolerate it surprisingly well
- Regular glucose monitoring and vet check-ups to adjust dosing
- Never adjust insulin dose without veterinary guidance — hypoglycaemia (low blood sugar) is dangerous
Diet — High Protein, Low Carbohydrate
- The optimal diabetic cat diet is high protein, low carbohydrate — wet food is strongly preferred over dry
- Cats are obligate carnivores; carbohydrates spike blood sugar
- Prescription diets: Hill’s m/d, Royal Canin Glycobalance/Glycoadvanced (new 2026), Purina DM
- Some commercially available wet foods with high protein/low carb profiles may also be suitable — consult your vet
- Consistency: same food, same amounts, same times each day
FAQs
What is diabetic remission and how likely is it?
Remission means the cat’s blood sugar normalises and insulin injections are no longer needed. It occurs in a significant proportion of cats — especially those diagnosed early, treated promptly with insulin, switched to a high-protein/low-carb diet, and managed to a healthy weight. Some cats achieve remission within weeks. However, approximately 30% of cats that achieve remission will relapse and require insulin again, so ongoing monitoring remains essential even after remission.
Reviewed by Dr. Sarah Jenkins, MRCVS
Dr. Jenkins is a fully practicing veterinary surgeon in the UK with over 15 years of clinical experience in small animal medicine and canine behaviour. She reviews and verifies our health content to ensure medical accuracy.
