Diabetes in Cats: Signs, Diagnosis and Management

Diabetes is one of the most common hormone problems vets see in cats, and it usually turns up in middle-aged, overweight or older cats. The good news is that once it's picked up, it's very manageable at home, and some cats recover well enough to stop treatment altogether. The key is spotting the early signs and getting a diagnosis before your cat becomes seriously unwell.

This is a serious condition, so treat everything below as background reading rather than a substitute for veterinary care. Only a vet can diagnose diabetes and set up a treatment and monitoring plan for your individual cat.

What diabetes actually is in cats

Diabetes mellitus means the body can't control blood sugar (glucose) properly. Normally the pancreas releases a hormone called insulin, which lets glucose move out of the blood and into the body's cells to be used for energy. In a diabetic cat that system breaks down, so glucose builds up in the blood while the cells effectively go hungry.

Most cats develop what looks like type 2 diabetes, where the body still makes some insulin but the cells stop responding to it properly (insulin resistance), often on a background of being overweight. This is different from dogs, who usually develop type 1, where the pancreas simply stops making insulin. That difference matters, because it's part of why remission is realistically possible in cats and rarely is in dogs.

The signs to look for

Diabetes tends to creep in, so the changes are easy to miss or put down to age. The four classic early signs are:

• Drinking much more than usual (increased thirst). You might notice the water bowl emptying faster, your cat drinking from taps, ponds or puddles, or the toilet bowl.
• Weeing more (bigger or more frequent wet patches in the litter tray, sometimes accidents outside it).
• Weight loss, often quite sudden, in a cat that was previously chunky.
• A normal or increased appetite despite that weight loss. A cat that's eating well but still getting thinner is a red flag.

As things progress you may also see a dull, greasy or unkempt coat because the cat stops grooming properly, low energy, and in some cats a distinctive flat-footed, wobbly back-leg walk where they stand on their hocks instead of up on their toes. That last sign is caused by nerve damage (diabetic neuropathy) and needs urgent veterinary attention.

If your cat is off its food, being sick, very lethargic, weak, or has sweet, fruity-smelling breath, treat it as an emergency and phone a vet straight away. These can be signs of diabetic ketoacidosis, a life-threatening complication.

What raises a cat's risk

Some cats are more prone than others. Known risk factors include:

| Risk factor | Why it matters | | --- | --- | | Being overweight | The single biggest modifiable risk. Excess fat drives insulin resistance. | | Middle-aged to senior | Most diagnoses are in cats over about seven years old. | | Male, neutered cats | Statistically more commonly affected than females. | | Inactive, indoor lifestyle | Less exercise makes weight gain and insulin resistance more likely. | | Burmese breed | Have a recognised genetic predisposition, particularly in the UK and Australia. | | Long-term steroid treatment | Some medicines can push blood sugar up. | | Other illnesses | Pancreatitis, an overactive thyroid, or a rarer hormone condition called acromegaly can all be involved. |

Keeping your cat at a healthy weight is the most useful thing you can do to lower the risk. If you're not sure whether your cat is carrying too much, your vet or a vet nurse will happily body-condition score them for free at a routine visit.

How vets diagnose it

Diagnosis isn't quite as simple as one blood test, and it's worth understanding why. Cats are famous for getting stressed at the vet's, and stress alone can push their blood glucose up temporarily. This is called stress hyperglycaemia, and it's the reason a single high reading isn't enough to confirm diabetes.

To get a clear picture, a vet will usually combine:

• A blood glucose test, often repeated, to check the level is genuinely and persistently high.
• A fructosamine blood test, which reflects average blood sugar over the previous couple of weeks and isn't affected by a one-off stressy visit. This is a really useful way to separate true diabetes from stress.
• A urine test, because diabetic cats spill glucose into their urine. Urine is also checked for signs of infection and ketones.
• A general health check and sometimes further tests, to look for other conditions that often travel alongside diabetes.

If your cat is a bundle of nerves at the clinic, ask about calmer options such as a cat-only waiting area, a covered carrier, or having samples taken at home. It genuinely improves the accuracy of results.

Treatment: what managing a diabetic cat looks like

Most cats are managed at home with a combination of insulin injections and diet, and honestly, most owners are surprised by how quickly it becomes routine.

Insulin injections

Insulin is given as a small injection under the skin, usually twice a day, about twelve hours apart, ideally after a meal. The needles are tiny and most cats barely notice them once you both get the hang of it. Your vet or nurse will show you the technique, where to inject, how to store the insulin, and how to draw up the exact dose.

A few ground rules that keep cats safe:

• Never change the dose yourself without speaking to your vet. Too much insulin can drop blood sugar dangerously low.
• Feed as advised, usually around the time of injection, so there's glucose coming in to match the insulin.
• If your cat won't eat or is unwell, phone your vet before injecting. Giving a full dose to a cat that hasn't eaten is a common cause of a hypo.

Getting the dose right takes a bit of fine-tuning over the first few weeks, with your vet adjusting based on how your cat responds. Patience early on pays off.

A newer, insulin-free option for some cats

There's now a once-daily oral liquid medicine licensed in the UK called velagliflozin (brand name Senvelgo). It belongs to a group of drugs called SGLT2 inhibitors and works by making the kidneys flush excess glucose out in the urine, rather than by replacing insulin. It's given by mouth, avoids injections, and is licensed for otherwise healthy cats that are newly diagnosed and haven't already been started on insulin.

It isn't right for every cat, and it does carry a specific risk of a dangerous complication (ketoacidosis) in cats that aren't making enough of their own insulin, so it needs careful vet supervision and monitoring, especially in the first few weeks. It's very much a conversation to have with your vet at diagnosis rather than a DIY choice, but it's worth knowing the option exists.

Diet

Diet does a lot of the heavy lifting in feline diabetes. The evidence points strongly towards a high-protein, low-carbohydrate diet, and wet food usually fits that bill better than dry. Lower carbohydrate intake reduces the glucose load hitting the bloodstream after meals, which makes blood sugar easier to control and improves the chances of remission.

Practical points:

• Your vet may recommend a specific veterinary diabetic diet. Don't switch foods or add treats without checking, as it changes the sums.
• Try to feed consistent amounts at consistent times.
• If your cat is overweight, controlled, gradual weight loss is a goal, but crash diets are dangerous for cats, so this must be vet-guided.

Remission: yes, it really happens

Here's the hopeful part. Because many cats have that type-2-like picture, some go into remission, meaning their blood sugar settles enough that they no longer need insulin. It's most likely when diabetes is caught early, when the cat is switched promptly to a low-carbohydrate diet, when any excess weight comes off, and when good blood-sugar control is achieved quickly. Cats in remission still need monitoring, because diabetes can return, but plenty of cats live long, comfortable lives after coming off treatment.

Monitoring at home

Good monitoring is what keeps a diabetic cat stable and safe. Alongside vet check-ups, keep an eye on the everyday signs: how much your cat is drinking and weeing, appetite, energy, and weight. A simple diary or notes on your phone makes trends easy to spot.

Many owners also do some form of glucose monitoring at home, which your vet can set up:

• A handheld glucometer using a tiny drop of blood, usually from the ear.
• A continuous glucose monitor (CGM), a small sensor that sits on the skin and reads glucose continuously, staying in place for up to around two weeks. Lots of owners find these far less stressful than repeated pricks, and they give a much fuller picture.

Know the signs of a hypo

The most important emergency to recognise is hypoglycaemia (blood sugar dropping too low), usually from too much insulin relative to food. Warning signs include unusual quietness, wobbliness, weakness, disorientation, hunger, trembling, and in severe cases collapse or seizures.

If you suspect a hypo and your cat can still swallow, rub a little honey or a glucose syrup onto the gums and contact your vet immediately. If your cat is collapsing or fitting, it's a 999-style emergency, phone the vet on the way in.

The cost side: be realistic and plan ahead

Diabetes is a long-term condition, and it's fair to say it isn't a cheap one to manage. On top of the initial diagnosis and stabilisation, you're looking at ongoing costs for insulin, needles and syringes, a prescription or specialist diet, monitoring equipment, and regular vet re-checks and blood tests, potentially for years.

The most important money point is about insurance. If you already have a lifetime pet insurance policy before your cat is diagnosed, ongoing diabetes care is usually covered up to your policy limits. But insurance never covers pre-existing conditions, so once a cat has been diagnosed you won't be able to insure that condition afterwards. The takeaway: insure while your cat is young and healthy, and check the wording on ongoing and chronic conditions.

If cost is a worry, talk to your vet early and honestly. Some owners qualify for help through charities such as the PDSA or Blue Cross, and vets can often prioritise the essentials to keep a cat safe.

A quick owner's checklist

• Watch for the big four: more drinking, more weeing, weight loss, unchanged or bigger appetite.
• Get any of those signs checked by a vet, don't wait and see.
• Expect blood and urine tests, including fructosamine, to confirm the diagnosis.
• Learn the injection technique thoroughly, and never alter the dose without your vet.
• Feed a vet-recommended high-protein, low-carb diet, consistently.
• Keep a simple daily diary and ask about home glucose or CGM monitoring.
• Know the hypo signs and keep honey or glucose gel in the house.
• Weight control and early diagnosis give the best shot at remission.

Diabetes in a cat sounds daunting on the day of diagnosis, but thousands of UK owners manage it every day, and their cats go on to live happy, well cats' lives. With early action, a good routine and a supportive vet, this is a condition you and your cat can absolutely live well with.

Sources

• PDSA – Diabetes in cats
• Blue Cross – Diabetes in cats
• Royal Veterinary College – Guide to feline diabetes (PDF)
• International Cat Care – Diabetes mellitus in cats: treatment
• Cats Protection – Diabetes
• Veterinary Medicines Directorate – Senvelgo (velagliflozin) SPC (PDF)