The cat who had spent fifteen years ignoring her water fountain suddenly cannot get enough of it. The litter box, scooped daily, is now full of heavy, sodden clumps by lunchtime. She is eating like a kitten and somehow losing weight. Owners often think she is "just getting old" — but in a middle-aged or older cat, those four changes together are the classic opening of diabetes mellitus.

Feline diabetes is one of the most common endocrine diseases of cats, and in important ways it is a different disease from canine diabetes. Cats can sometimes go into remission, especially if treatment starts early. The treatment toolkit has expanded dramatically in the last few years with the FDA approval of two oral medications. Here is what current veterinary science says about how diabetes shows up in cats, why it happens, and what good care looks like in 2026.

How Feline Diabetes Differs From Canine Diabetes

Most diabetic dogs have a disease that resembles human type 1 diabetes: the insulin-producing beta cells in the pancreas are progressively destroyed, and lifelong insulin injections are required.

Most diabetic cats have a disease that looks much more like human type 2 diabetes. The pancreas still produces insulin, at least early on, but the body's tissues become resistant to it, and the beta cells eventually exhaust themselves trying to keep up. A peptide called islet amyloid polypeptide (amylin) is co-secreted with insulin in cats and, in chronic insulin resistance, deposits as amyloid in the islets — a process strikingly similar to what is seen in human type 2 diabetes. This is why obesity, inactivity, and chronic high-carbohydrate intake are such powerful drivers of feline diabetes, and why losing weight and lowering carbohydrate intake can sometimes reverse the disease.

How Common It Is, and Who Gets It

Across populations, diabetes affects roughly 0.5% to 1% of cats, with most studies clustering around 1 in 200 to 1 in 100, and the rate has been climbing for decades alongside feline obesity. The typical patient is an overweight, neutered, middle-aged-to-senior male cat, often kept indoors and fed predominantly on dry food.

The most consistently identified risk factors are:

The Warning Signs

The classic four signs of feline diabetes are the same "three Ps plus weight loss" used in dogs, just expressed in feline ways:

Less specific signs include a dull, unkempt coat (diabetic cats often stop grooming well), lethargy, and sometimes vomiting. One sign is unique enough to be worth its own line: a plantigrade stance, where the cat walks with the hocks dropped to the floor instead of up in the air. This is caused by diabetic neuropathy — nerve damage from chronic hyperglycemia — and is essentially specific to long-standing or poorly controlled diabetes. It is often reversible with good glycemic control.

The dangerous endpoint of unrecognized or poorly controlled feline diabetes is diabetic ketoacidosis (DKA), in which the body, unable to use glucose, breaks down fat into ketones and tips into severe acidosis. A diabetic cat who suddenly stops eating, vomits, becomes weak or dehydrated, or develops a sweet, fruity smell on the breath needs an emergency veterinary visit.

How Vets Diagnose It

Feline diabetes is diagnosed by demonstrating persistent hyperglycemia together with glucosuria in a cat with compatible clinical signs. There is one important catch in cats that does not apply nearly as much in dogs: stress hyperglycemia. A frightened cat at the clinic can briefly run a blood glucose well above normal — sometimes high enough to spill into the urine — without being diabetic at all.

For that reason, the workup for a suspected diabetic cat almost always includes:

Treatment in 2026: A Bigger Toolkit

For decades, treatment for feline diabetes meant insulin injections plus a diet change. That is still the foundation, but the picture has changed in two important ways: the recognition that low-carbohydrate diets dramatically improve outcomes, and the FDA approval of oral SGLT2 inhibitors as a first-line option for selected cats.

1. Insulin. Insulin therapy is still the cornerstone for many newly diagnosed diabetic cats, especially those that are sick at presentation, ketotic, or have lost significant muscle. The insulins used most often in cats are long-acting analogs designed for stable, predictable blood-sugar lowering — protamine zinc insulin (ProZinc), which is FDA-approved for cats, and insulin glargine (Lantus) or detemir (Levemir), both used widely off-label. Doses are individualized and almost always given twice daily, every 12 hours, with very fine needles that most cats barely notice.

2. Oral SGLT2 inhibitors. In December 2022, the FDA approved bexagliflozin (Bexacat) as the first oral medication for feline diabetes — a once-daily flavored tablet — and in August 2023 it approved velagliflozin (Senvelgo), a once-daily oral liquid. Both are SGLT2 inhibitors: they block the kidney's reabsorption of glucose so that excess glucose is dumped into the urine, lowering blood sugar without requiring more insulin from the cat. They are not insulin substitutes for sick or ketotic cats: they are approved only for otherwise healthy, newly diagnosed diabetic cats who have not been on insulin and who still have meaningful pancreatic function. Both labels carry boxed warnings about the need for careful patient selection and the risk of euglycemic diabetic ketoacidosis (eDKA) — a form of DKA in which blood glucose looks normal or only mildly elevated, which can fool owners and clinicians. Cats on these drugs need close early monitoring and clear owner education about loss of appetite, vomiting, or lethargy as red flags.

3. Diet. A diet that is high in protein and low in carbohydrate, often a prescription canned diabetic formula, lowers post-meal glucose spikes and substantially improves the chances of remission. Multiple studies and the iCatCare/ISFM consensus guidelines support low-carb diets as part of standard feline diabetes care. Wet food also gently increases water intake, which is helpful for diabetic cats prone to urinary tract infections.

4. Weight loss in obese cats. Weight loss is therapy, not just prevention. Even modest, gradual weight loss markedly improves insulin sensitivity. The goal is steady, slow loss — typically not more than 0.5% to 1% of body weight per week — in obese cats, ideally under a veterinarian's plan, because rapid weight loss in cats can trigger hepatic lipidosis.

5. Monitoring. The biggest recent shift in feline diabetes care is the wide adoption of continuous glucose monitors (CGMs), especially the FreeStyle Libre system, which has been validated in cats and lets owners track interstitial glucose at home for up to two weeks at a time. Because stress hyperglycemia distorts in-clinic glucose curves more in cats than in any other species, CGMs have been transformative. Most veterinarians today combine clinical signs, at-home water intake and urination notes, fructosamine every few months, and CGM data to fine-tune therapy.

Remission: The Big Difference From Dogs

Unlike dogs, a meaningful fraction of diabetic cats can stop needing insulin entirely if their disease is controlled quickly. In the influential ProZinc and glargine studies, remission rates approached 80% or more in cats whose tight glycemic control was achieved within the first 6 months of diagnosis, and dropped to roughly a third in cats whose control was delayed beyond that window. Across less-selected populations, real-world remission rates are lower — typically 20% to 40% — but still very much worth pursuing.

The recipe for remission, distilled across the major guidelines, is consistent: diagnose early, treat aggressively from day one with insulin (or, in suitable cats, an SGLT2 inhibitor), feed a low-carb diet, get obese cats lean, and monitor closely enough to catch good control as soon as it appears so that doses can be tapered. A cat in remission is not "cured" — beta-cell function is fragile, and many cats relapse months or years later — but every remitted cat earns months or years free of injections and at lower risk of long-term complications.

What to Watch for at Home

Once your cat is on therapy, your job becomes pattern recognition. Helpful habits include:

The single most important emergency to recognize in cats on insulin is hypoglycemia — blood sugar too low, usually from too much insulin, a missed meal, or an unexpected step into remission. Warning signs include weakness, wobbliness, glassy eyes, disorientation, trembling, and in severe cases seizures or collapse. If your cat is conscious and able to swallow, rubbing a small amount of corn syrup or glucose gel onto the gums and calling your veterinarian immediately is the standard first response. Every household with a diabetic cat should keep a labeled tube of glucose gel within easy reach.

Outlook

The prognosis for a well-managed diabetic cat is good. With early diagnosis, prompt control, a low-carb diet, and weight management, many cats live for years on therapy at a quality of life essentially indistinguishable from a non-diabetic cat of the same age — and a meaningful share will earn a stretch of remission along the way. The takeaway for owners is the same as for dogs: drinking and peeing changes in a middle-aged or senior cat are not a sign of "just getting old." They are one of the most teachable opening signs in feline medicine, and acting early is what makes feline diabetes one of the most treatable chronic diseases your cat is likely to face.