Diabetes in Cats: Symptoms, Diagnosis and Treatment

What diabetes in cats is

Insulin is the hormone that moves sugar from the blood into the body's cells for energy. In diabetes mellitus the body either does not make enough insulin or the cells stop responding to it, so sugar builds up in the blood and spills into the urine while the body's cells go short of fuel. VCA Animal Hospitals reports that 85 to 95 percent of diabetic cats have Type II diabetes, the form linked to obesity, in which the cells respond poorly to insulin.

Cornell Feline Health Center estimates that between 1 in 100 and 1 in 500 cats will be diagnosed in their lifetime. The biggest risk factors are obesity, older age, physical inactivity, being male, and the use of steroid medicines. VCA describes it as the second most common hormone disease in cats, seen most often in middle-aged to senior cats.

Symptoms of diabetes in cats

The four classic signs are increased thirst, increased urination, weight loss and increased appetite. You may notice the water bowl emptying faster, bigger or more frequent clumps in the litter box, urinating outside the box, or a cat that is always hungry but getting thinner. VCA notes that early signs are easy to miss in outdoor cats and in cats eating mostly canned food, which supplies much of their water.

As diabetes progresses, some cats become less active, groom less and develop an unkempt coat. Cornell describes an unusual sign seen in some cats with poorly controlled diabetes: walking or standing with the hocks of the back legs touching the ground, rather than up on the toes. It is not painful and often improves with treatment. These signs overlap with kidney disease and hyperthyroidism, so testing is needed.

When to call your vet today

Book a visit within a few days if your cat is drinking or peeing more, losing weight, or eating more than usual. Call the same day if your cat with those signs also stops eating, vomits, or seems unusually tired, because untreated diabetes can progress to a serious complication called diabetic ketoacidosis.

If your cat is already diabetic, call your vet promptly when appetite drops, vomiting starts, water intake changes markedly, or your cat seems wobbly or weak. Cornell advises never changing an insulin dose without your vet's guidance, so any change in how your cat seems is a reason to phone, not to adjust treatment yourself.

When it's an emergency

Go to your vet or the nearest emergency vet immediately if a diabetic cat is weak, trembling, wobbly as if drunk, unusually sleepy, having a seizure or will not wake normally. VCA states that low blood sugar is a medical emergency, and it usually happens when there is too much insulin for the food the cat has eaten. Follow any low-blood-sugar plan your vet has given you; Cornell describes offering food or rubbing a little honey on the gums of a cat that is awake, and warns never to put anything in the mouth of a cat that is seizing or unconscious.

Diabetic ketoacidosis is the other emergency. Cornell describes it as requiring hospitalization. A cat that is vomiting, refusing food, very lethargic, dehydrated or breathing unusually, especially one not yet diagnosed or one whose diabetes is poorly controlled, needs to be seen the same day.

What you can safely do at home

Never give human diabetes medicine or supplements claimed to lower blood sugar, and do not start, stop or change insulin without your vet. Before a diagnosis, the most useful thing you can do is measure how much your cat drinks over a day, note litter box changes, and weigh your cat weekly if you can, then share those notes with your vet.

For a diabetic cat, consistency is the heart of home care. VCA suggests keeping a log of insulin timing and amount, food and water intake, and weekly weight, and notes that urine strips are not reliable for adjusting insulin. Keep your cat at a healthy weight under your vet's direction, encourage daily play, and feed the diet your vet recommends.

Consistent meal times help when your cat is on insulin, and an automatic cat feeder can serve measured portions on schedule.

What the vet will likely check

Diagnosis is based on the typical signs together with persistently high blood sugar and sugar in the urine. Because the stress of a vet visit alone can raise a cat's blood sugar, VCA and Cornell note that a fructosamine test, which reflects average blood sugar over roughly the previous one to two weeks, is often used to confirm the diagnosis. Your vet will also check for other conditions that commonly occur alongside or look similar, such as urinary infection, kidney disease, pancreatitis and hyperthyroidism.

Insulin injections under the skin are the standard treatment, and your vet team will show you how to give them. Cornell notes that oral medicines approved in 2023 can suit some newly diagnosed, otherwise healthy cats that still make some insulin. A high-protein, low-carbohydrate diet, often wet food, and gradual weight loss for overweight cats are a key part of treatment. Regular blood sugar checks, either at the clinic or at home, guide the plan over time.

Remission, prevention and outlook

Cats are unusual in that diabetes can go into remission. Cornell explains that early, aggressive treatment gives the best chance of a cat no longer needing insulin, and that if remission has not happened within about six months, lifelong treatment is likely. Cats in remission still need a suitable diet and monitoring, because some relapse.

The best prevention is keeping your cat lean and active. Maintaining a healthy weight and daily play are the main ways Cornell describes to lower the risk, and regular checkups help catch rising blood sugar before signs become severe. Many diabetic cats live long, comfortable lives with consistent care.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.