Explainer

Diabetes in Dogs and Cats: Signs, Insulin and Remission

The signs of diabetes in pets, how dogs and cats differ, insulin and diet, how cats can go into remission, and the emergency signs of low blood sugar.

Updated October 2026 · 8 min read · By the Hushku editorial team · 2 sources

Short answer

The classic signs of diabetes are drinking and peeing much more, a big appetite and weight loss. Most diabetic dogs need insulin injections for life. Cats usually have a type similar to human type 2, and with prompt treatment, insulin and a low-carbohydrate diet, many go into remission. Weakness, wobbliness or seizures in a pet on insulin can mean low blood sugar, which is an emergency.

Key facts

Classic signs: drinking and peeing more, big appetite, weight loss.
Most diabetic dogs need insulin for life.
Obese cats are up to four times more likely to develop diabetes.
Many cats go into remission with prompt treatment and a low-carb diet.

Definition

Diabetes mellitus is a condition in which the body either doesn't make enough insulin or doesn't respond to it properly, so sugar (glucose) builds up in the blood and spills into the urine.

Insulin lets the body's cells take in glucose for energy. Without enough of it, cells are starved even though blood sugar is high, so the body breaks down fat and muscle, and a diabetic pet loses weight while eating more.

Dogs usually develop a form similar to human type 1: the insulin-producing cells of the pancreas are lost, so dogs nearly always need insulin for life. Most diabetic dogs also develop cataracts, which can cause blindness but can often be treated surgically.

Cats most commonly have type 2 diabetes. Cornell Feline Health Center estimates between 1 in 100 and 1 in 500 cats will be diagnosed in their lifetime. Obesity, older age, inactivity, being male and steroid treatment raise the risk, and obese cats are up to four times more likely to develop diabetes than cats at an ideal weight.

Signs and symptoms

Drinking much more water
Peeing more, accidents or a soaked litter box
A bigger appetite
Weight loss despite eating well
Lethargy
Cloudy eyes in dogs (cataracts)
In cats: walking flat on the hocks of the back legs (a 'plantigrade' stance)

Causes and risk factors

Dogs: loss of insulin-producing cells, often immune-related; some breeds are predisposed
Cats: insulin resistance linked to obesity, inactivity and age
Pancreatitis
Cushing's disease and hormonal changes in unspayed female dogs
Long-term steroid treatment

Treatment

Insulin injections, usually twice daily with meals
A consistent diet and feeding routine
Cats: a high-protein, low-carbohydrate diet, often wet food
Regular monitoring of signs, weight and blood glucose, sometimes with a continuous glucose monitor
Spaying unspayed female dogs, as hormones affect insulin
Treating any infections or other diseases that affect control

Prevention

Keep pets at a healthy weight, especially cats
Encourage daily activity and play
Feed cats a diet appropriate for an obligate carnivore
Watch for increased thirst in middle-aged and older pets

Remission in cats

Early, intensive treatment can lead to remission in cats, where blood sugar stays normal without insulin. Cornell notes that cats treated promptly, cats whose diabetes was triggered by steroids, and cats on glargine insulin are more likely to go into remission, and that if remission hasn't happened within about six months, lifelong insulin is likely. A low-carbohydrate diet improves control.

Low blood sugar: an emergency

Too much insulin, a missed meal or vomiting after an injection can cause hypoglycaemia. Signs include weakness, wobbliness, trembling, confusion, seizures and collapse. If your pet is conscious, rub a little honey or syrup on its gums and call your vet or emergency clinic immediately. Never give insulin to a pet that hasn't eaten without checking with your vet first.

Diabetic ketoacidosis

Untreated or poorly controlled diabetes can lead to diabetic ketoacidosis (DKA): vomiting, not eating, lethargy, dehydration and sometimes sweet-smelling breath. DKA is life-threatening and needs hospital treatment.

Living with a diabetic pet

Most owners quickly get used to giving injections. Keep meals and insulin at the same times each day, keep a log of doses, appetite, thirst and weight, and share it with anyone who cares for your pet so doses aren't missed or doubled.

Free tools for this

Sources

We check guides against veterinary sources and update them when guidance changes. How we write and review.

Questions.

How long do diabetic dogs live?

With good control, many diabetic dogs live a normal or near-normal lifespan. The first months are often the hardest while the right insulin dose is found.

Can diabetes in dogs be cured?

Rarely. Dogs usually need insulin for life. Some unspayed female dogs improve after spaying if diabetes is caught early.

What if I miss an insulin dose?

Don't double the next dose. Call your vet for advice; giving too much insulin is more dangerous than a missed dose.