What diabetes is and how to recognize it in cats
Diabetes mellitus is a disease in which the body can no longer keep blood sugar (glucose) in a normal range, so glucose builds up in the blood and spills into the urine. The form cats almost always get closely mirrors human type 2 diabetes: per the Cornell Feline Health Center, the body’s cells stop responding properly to insulin, the hormone that moves glucose into cells for fuel. It is one of the more common hormonal diseases of cats — the Cornell Feline Health Center estimates that between 1 in 100 and 1 in 500 cats will be diagnosed with diabetes during their lifetime. The good news is that it is both treatable and, in many cats, manageable for years.
The signs owners notice first are remarkably consistent. According to the Cornell Feline Health Center, the two most common are increased thirst and urination and weight loss despite a good appetite — a cat that is hungry and eating well yet steadily getting thinner. The Merck Veterinary Manual adds increased appetite (polyphagia), though it notes appetite can also fall in up to half of diabetic cats, along with lethargy and a dull coat. In more advanced cases, the Cornell Feline Health Center describes nerve damage in the hind limbs that produces a plantigrade stance — walking with the hocks dropped close to the ground — which is not painful and often improves with treatment. None of these signs is unique to diabetes, which is exactly why they call for a vet visit rather than a guess.
What causes diabetes in cats
The biggest driver you can actually do something about is body weight. The Cornell Feline Health Center reports that obese cats are up to four times more likely to develop diabetes than cats at an ideal weight, because excess fat makes the body resistant to insulin. On top of that resistance, cats have a second problem in the pancreas itself: the Merck Veterinary Manual describes a buildup of amyloid (a protein deposit derived from islet-associated polypeptide) in the insulin-producing islets, along with damage to the beta cells that make insulin. The result looks much like human type 2 diabetes — the cat both responds poorly to insulin and gradually makes less of it.
Several other factors raise the risk. The Cornell Feline Health Center points to increasing age, physical inactivity, and being male, and notes that certain drugs — especially glucocorticoids (steroids), sometimes used for conditions like feline asthma — can trigger or worsen diabetes. The Merck Veterinary Manual adds progestin hormones and lists several predisposed breeds, including the Burmese, Tonkinese, Norwegian Forest Cat, Russian Blue, and Abyssinian, with diabetes most common in middle-aged to older cats. Weight, age, and inactivity tend to travel together, which is why an overweight, under-exercised senior cat sits in a genuinely higher-risk group.
Diagnosis, treatment, and when to see your vet
Diagnosing feline diabetes takes more than one high reading, because cats are famous for stress hyperglycemia — a vet visit alone can spike a cat’s blood sugar. The Merck Veterinary Manual states that diagnosis requires persistent hyperglycemia (high blood glucose) together with glucosuria (glucose in the urine), and that a fructosamine blood test is used to tell true diabetes from stress: per the Cornell Feline Health Center, fructosamine reflects the average blood glucose over roughly the prior two weeks, so it stays normal with momentary stress and rises with sustained disease. Treatment, per the Merck Veterinary Manual, is insulin — given by injection under the skin, typically every 12 hours — paired with dietary change; longer-acting insulins such as glargine are commonly used. The Merck Veterinary Manual also describes a newer oral drug class, the SGLT2 inhibitors (velagliflozin and bexagliflozin, first licensed for cats around 2022–2023), reporting that glucose and fructosamine were normal in over 80% of treated cats by day 180; importantly, these are reserved for newly diagnosed cats and are not appropriate for every patient, so the choice belongs with your vet.
Because diet supports insulin but does not replace it, and because dosing errors cut both ways, this is a condition to co-manage closely with a veterinarian rather than self-treat. See your vet promptly if your cat is drinking or urinating noticeably more, losing weight, eating ravenously or suddenly not eating, or seeming run-down. Treat certain situations as an emergency: untreated diabetes can progress to diabetic ketoacidosis (DKA), which the VCA Animal Hospitals describe as life-threatening and fatal if untreated, with signs including vomiting, marked weakness or lethargy, dehydration, and loss of appetite — cats with DKA need hospitalization and intravenous care. Equally urgent in the other direction is hypoglycemia (blood sugar dropping too low), which the Cornell Feline Health Center links to weakness, wobbliness, seizures, and coma. Any collapse, seizure, or persistent vomiting in a diabetic cat is a same-day call to your vet or an emergency clinic.
The diet connection: why low-carb matters for cats
Diet is where cats differ most encouragingly from dogs. Cats are obligate carnivores built to run on protein and fat with very little carbohydrate, so a low-carbohydrate, high-protein diet works with their physiology. The Merck Veterinary Manual recommends exactly that — a high-protein, low-carbohydrate diet, with canned (wet) foods preferred over dry, which tend to be higher in carbohydrate. The payoff is real: the 2018 AAHA Diabetes Management Guidelines report that diabetic cats fed a high-protein, low-carbohydrate diet alongside insulin have achieved diabetic remission — blood sugar normalizing so the cat no longer needs insulin — with published remission rates spanning a wide range across studies. This is a feline-specific opportunity: dogs almost never go into remission, while many cats can, especially when treatment starts early and glycemic control is good. Tufts Petfoodology agrees that in cats, reducing dietary carbohydrate can improve diabetic control, while cautioning that the ideal carbohydrate level is not settled and the diet should be individualized.
Honesty matters here: remission is a genuine possibility, not a guarantee. The 2018 AAHA guidelines note that the best odds come from getting blood sugar under control early — often within the first six months of diagnosis — using appropriate insulin (glargine and detemir are highlighted) together with the low-carb diet. Not every cat remits, and some that do can relapse later, so even a cat in remission needs ongoing monitoring. Weight management is the other half of the equation, since trimming obesity directly reduces insulin resistance. One more caution from Tufts Petfoodology: the long-standing link between dry food and feline diabetes is likely driven as much by calorie-dense food fed free-choice (and the resulting obesity) as by carbohydrate alone — so portion control matters too. If you are comparing specific products, our guide to the Best Cat Food for Diabetes breaks down what to look for, but always match the plan to your cat with your vet.
Managing diabetes day to day — and what to avoid
Day-to-day management of a diabetic cat is mostly about consistency and teamwork with your vet. The Merck Veterinary Manual notes that after the initial insulin dose is chosen, cats are monitored with clinical signs and blood glucose measurements, with starting doses kept deliberately conservative to avoid driving blood sugar too low. In practice that means feeding and giving insulin on a consistent schedule, keeping meals and portions steady, and many owners learn home glucose monitoring so problems are caught early between vet rechecks. Because a diabetic cat’s needs shift as the disease — and ideally remission — progresses, expect periodic blood and fructosamine rechecks to be a normal part of care rather than a sign something has gone wrong.
Some things are worth actively avoiding. Don’t free-feed high-carbohydrate dry food to an at-risk or diabetic cat, and don’t let weight creep up, since obesity is the central modifiable driver per the Cornell Feline Health Center. Never change the insulin dose or stop insulin on your own — abruptly stopping it can tip a cat into diabetic ketoacidosis, and giving too much can cause dangerous hypoglycemia; both are emergencies, so dose changes belong with your vet. Likewise, don’t overhaul the diet overnight without veterinary guidance, because the carbohydrate change can rapidly alter insulin needs. Above all, don’t ignore early signs: the sooner increased thirst, weight loss, or appetite changes are investigated, the better the odds of good control — and, in cats, of remission.
Frequently asked questions
Can a cat with diabetes go into remission?
Yes, and this is a real difference between cats and dogs. According to the 2018 AAHA Diabetes Management Guidelines, many diabetic cats fed a high-protein, low-carbohydrate diet together with insulin can reach remission, meaning their blood sugar normalizes and they no longer need insulin injections. Remission is most likely when treatment starts early and blood sugar is well controlled, but it is not guaranteed and some cats relapse, so a cat in remission still needs ongoing monitoring with your vet.
What is the best diet for a diabetic cat?
Most authorities favor a low-carbohydrate, high-protein diet because cats are obligate carnivores that handle carbohydrate poorly. The Merck Veterinary Manual recommends a high-protein, low-carbohydrate food and notes that canned (wet) foods are generally preferred over dry, which tends to be higher in carbohydrate. Tufts Petfoodology agrees that reducing carbohydrate can improve diabetic control in cats while stressing the diet should be individualized. Diet supports treatment but does not replace insulin, so never change food or insulin without your vet.
Does every diabetic cat need insulin injections?
Most do, at least to start. The Merck Veterinary Manual identifies insulin given by injection as the standard treatment, paired with dietary change. A newer oral drug class, the SGLT2 inhibitors, exists for cats, but the Merck Veterinary Manual notes these are intended for newly diagnosed cats and are not appropriate for every patient. Whether your cat needs insulin, an oral option, or can eventually come off treatment in remission is a decision to make with your veterinarian based on testing and monitoring.
For diet-side context, see Best Cat Food for Diabetes, Best Cat Food for Weight Loss. To check whether your cat’s food matches the rubric criteria discussed above, paste the ingredient list into the KibbleIQ analyzer. For scoring methodology context, see our published methodology.
Related condition deep-dives: Hyperthyroidism in Cats · Pancreatitis in Cats.