Diabetes in cats, updated: 2026 US guidelines move away from in-clinic glucose curves in favour of home monitors, and the new tablets aren't for every cat

What happened

On 1 November 2026 the US veterinary journal dvm360 published an interview with small animal internist Kelly Cairns. The discussion looks at what counts as success in treating diabetes mellitus in cats: not only test results, but also how the animal feels and the family's quality of life.

The prompt was the American Animal Hospital Association's (AAHA) guidelines on diabetes in dogs and cats, updated in 2026, which change several established approaches.

In-clinic glucose curves are no longer required

A diabetic cat used to be left in the clinic all day so that its glucose could be measured every few hours to build a "glucose curve". According to Cairns, AAHA's 2026 guidelines no longer recommend doing this routinely. The stress of the journey and of being in a clinic raises blood glucose in cats significantly, so the results may not reflect the real picture.

Home monitors

In-clinic curves are giving way to continuous glucose monitors, small devices attached to a cat's skin for several days or weeks. They measure glucose around the clock while the cat lives its normal life at home. Your vet can see how glucose changes after meals, after insulin and through the night, and fine-tune the dose.

How a monitor works

A continuous glucose monitor is a small disc that a vet attaches to a cat's skin, usually in the neck or shoulder area. A thin flexible filament under the skin measures glucose in the tissue fluid, and the data can be read with a phone or special device. A monitor can work for up to several weeks. Cats sometimes pull them off, so the site is protected, and owners need to check that it stays in place.

Why stress skews test results

Stress can raise a cat's blood glucose sharply, sometimes to levels that look like diabetes. A journey in a carrier, unfamiliar smells and dogs in the waiting room can all do this. So vets use additional measures such as fructosamine, which reflects average glucose over recent weeks, and consider measurements taken at home more reliable.

New tablets: which cats they suit

In recent years, tablets from the SGLT2 inhibitor group have become available for cats: bexagliflozin and velagliflozin. They help remove excess glucose in the urine and have become a convenient alternative to insulin injections for many cats. But as Cairns stresses, these drugs are contraindicated in cats that have ever received insulin, are receiving it now or have insulin-dependent diabetes.

Why ketones matter

The most dangerous complication of treatment with SGLT2 tablets is ketoacidosis, in which ketones build up in the blood and a cat can become seriously ill. So AAHA's 2026 guidelines suggest checking beta-hydroxybutyrate (ketone) levels on days 2, 3, 7 and 14 after starting treatment. If your cat becomes lethargic, stops eating or vomits during this time, see a vet urgently.

What remission means

Remission is when a cat has normal glucose levels for more than four weeks without insulin or tablets. According to data cited in the guidelines, about 30% of cats achieve remission, most often in the first six months after diagnosis. That's why it's so important to start the right treatment straight away and not put off seeing a vet.

What counts as success

Cairns stresses that success isn't just about numbers. A well-controlled cat doesn't drink or urinate excessively, maintains its weight, is active, looks good and has no episodes of low glucose. It also matters how manageable treatment is for the family: whether injection times work, whether the owner can give tablets and whether the cat's condition can be monitored at home.

How often your cat should see a vet

According to Cairns, even a stable diabetic cat should see a vet at least twice a year, and more realistically about four times. At the appointment the vet assesses weight, muscle mass and the condition of the coat and paws, discusses appetite, thirst and urination with you, and carries out tests if needed.

What's asked of owners

Treatment under the new guidelines asks owners to play a bigger part in monitoring: watching the cat's behaviour, keeping a diary, handling the monitor or giving injections, and telling the vet about changes in good time. The good news is that monitoring at home is less frightening for the cat and gives the vet more accurate data.

Signs of diabetes in a cat

• extreme thirst: the cat drinks a lot;
• frequent, heavy urination: the litter tray is wetter than usual;
• weight loss despite a good or even increased appetite;
• lethargy and a dull coat;
• weak back legs: the cat walks flat on its hocks, as if "squatting".

Which cats are at risk

Diabetes is more common in middle-aged and older cats, especially neutered males and overweight cats. The risk is raised by long-term treatment with certain hormonal drugs such as glucocorticoids and by a sedentary lifestyle. Many cases of diabetes in cats resemble type 2 diabetes in people and are closely linked to obesity.

Diet and diabetes

Diet is an important part of treatment. Vets often advise wet food high in protein and low in carbohydrate for diabetic cats, and gradual weight loss under veterinary supervision if they're overweight. It's best to feed on a schedule that fits in with insulin injections. Don't change food suddenly without asking your vet, as this can alter how much insulin your cat needs.

Excess weight and fasting

Losing weight helps many diabetic cats and improves the chances of remission. But a cat must lose weight slowly, under veterinary supervision. Sharply restricting food or fasting is dangerous for cats, as it can cause hepatic lipidosis, a serious condition in which the liver is overloaded with fat. So your vet should draw up a weight loss plan, and you should weigh your cat regularly.

Living with a diabetic cat

Diabetes in a cat calls for a routine: meals and injections at the same time, regular monitoring and vet visits. Many owners quickly get used to it and can give an injection in a few seconds. Before going on holiday, find someone who can give injections or a clinic where your cat can stay. Everyone caring for your cat should have clear instructions.

The danger of low blood glucose

If a cat is on insulin, glucose that's too low, or hypoglycaemia, is life-threatening. Signs include weakness, an unsteady gait, trembling, confusion and seizures. Contact your vet immediately if this happens. Vets explain in advance to owners of cats on insulin what to do if hypoglycaemia is suspected and how to avoid dosing errors.

How to handle insulin

• Store insulin as instructed, usually in the fridge.
• Mix the vial gently as your vet has shown you, without shaking it hard.
• Use syringes for the type of insulin prescribed.
• Keep a diary of doses, injection times, appetite, weight and behaviour.
• Don't change the dose yourself, only in agreement with your vet.

If your cat won't eat

If a cat on insulin refuses food, don't give the full dose "as usual": without food, glucose can fall too low. Contact your vet to find out what to do. Refusing food is a warning sign in itself in a diabetic cat and can point to complications developing.

Complications of diabetes in cats

Without treatment or with poor control, diabetes in cats leads to complications. The most noticeable is damage to the nerves of the back legs, which makes a cat walk flat on its hocks. Urinary tract infections are common, and the skin and coat deteriorate. The most dangerous complication is ketoacidosis, which needs urgent hospital treatment. Unlike in dogs, cataracts are rare in diabetic cats. Many complications improve once glucose is under control.

What this means for Europe

Vets in many countries read and use the US AAHA guidelines, including in Europe. Home glucose monitors and SGLT2 tablets are already used by European vets too, and velagliflozin is authorised for cats in the EU and the UK. European owners should talk to their vet about whether the new approach suits their cat, especially if glucose monitoring is currently limited to occasional tests in the clinic.

When to see a vet

See a vet if your cat starts drinking and urinating a lot, loses weight despite a good appetite or begins to walk squatting on its back legs. A diabetic cat needs urgent help if it's lethargic, refuses food, vomits, is unsteady on its feet, trembles or has seizures, especially in the first weeks after starting tablets or changing the insulin dose.