Diabetes in Dogs and Cats: Signs, Treatment, and Daily Care

What diabetes does in the body

The pancreas makes insulin, a hormone that moves sugar (glucose) from the blood into the body's cells. In diabetes, the body makes too little insulin or stops responding to it properly. Sugar builds up in the blood and spills into the urine, pulling extra water with it. That is why diabetic pets drink and urinate so much. The cells are short of fuel, so the body breaks down fat and muscle instead.

Dogs and cats usually develop different forms. Most diabetic dogs lose the cells that make insulin. This can follow immune damage or repeated bouts of pancreatitis, an inflammation of the pancreas. These dogs need insulin for the rest of their lives. Most diabetic cats have a form similar to type 2 diabetes in people. Their pancreas still makes some insulin, but the body responds to it poorly, and extra weight makes this worse.

Diabetes is not contagious. It cannot pass between pets or from pets to people.

Risk factors

In dogs, diabetes usually appears in middle age or later. Females are about twice as likely as males to develop it. Miniature Poodles, Dachshunds, and Schnauzers are among the breeds more often affected, though any dog can get it. In unspayed females, the hormones of the heat cycle and pregnancy work against insulin and can trigger the disease. Obesity, Cushing's disease, and long-term treatment with steroid or progestin hormone medicines also raise the risk.

In cats, the biggest risk factor is excess weight. Overweight cats are up to four times more likely to develop diabetes. Older age, male sex, an inactive lifestyle, and steroid medicines add to the risk. In some countries, Burmese cats also appear more prone.

Signs to watch for

The signs build slowly, so they are easy to put down to age or hot weather. Watch for these changes.

• Drinking much more water than usual
• Urinating more often or in larger amounts, bigger clumps in the litter box, or accidents in a house-trained dog
• A good or increased appetite with weight loss
• Low energy and a dull, untidy coat
• Infections that keep coming back, such as bladder or skin infections
• Cloudy eyes in dogs, caused by cataracts
• Weak back legs in cats, sometimes with the hocks sinking close to the ground

In cats that go outdoors, the extra drinking and urination can be easy to miss, and a slow loss of weight may be the first clue. Cataracts are common in diabetic dogs and can progress quickly after diagnosis, while they are rare in diabetic cats. The low, weak-legged stance in cats comes from nerve damage in poorly controlled diabetes. It is not painful and often improves with treatment.

When it is an emergency

Untreated or poorly controlled diabetes can lead to diabetic ketoacidosis. The body burns fat so fast that acids called ketones build up in the blood. This is life-threatening and needs hospital care, usually with intravenous fluids, insulin, and frequent blood tests. The opposite problem, low blood sugar, can happen during treatment. It usually follows too much insulin, a skipped meal, or unusual exercise, and it can also be fatal.

Contact a vet right away if your pet shows any of these signs.

• Vomiting or refusing food
• Weakness or unusual lethargy
• Fast breathing or signs of dehydration
• Trembling, wobbling, or confusion
• A seizure or collapse

It is worth asking your vet ahead of time what first aid they recommend for low blood sugar. Many advise rubbing a little honey or syrup onto the gums and then going straight to the clinic.

How vets diagnose it

A vet diagnoses diabetes from the typical signs together with blood sugar that stays high and sugar in the urine. One high reading is not always enough. Cats in particular can have a short-lived spike in blood sugar from the stress of a clinic visit. For this reason, vets often add a fructosamine test, which reflects the average blood sugar over roughly the previous two weeks.

Most vets also run general blood work and a urine test. These check for ketones, urinary infections, and other conditions that make diabetes harder to control, such as pancreatitis or Cushing's disease.

How it is treated

Most diabetic pets need insulin injections under the skin, usually twice a day about 12 hours apart, given with meals. The needles are very fine, and most pets get used to the injections quickly. Your clinic will show you how to give them. The vet chooses the type of insulin and the dose, then adjusts it over the following weeks. To do this, they may run a glucose curve, which means checking blood sugar every one to two hours for about 12 hours, at the clinic or at home.

Diet is part of treatment. Dogs do best with the same food, in the same amount, at the same times every day, and vets often suggest a diet higher in fiber. Cats usually benefit from a high-protein, low-carbohydrate diet, often wet food. Overweight pets need a weight-loss plan, and for cats the loss should be slow and planned with the vet. Unspayed female dogs are usually spayed, and steroid medicines are stopped or changed where possible.

For some cats, a newer oral medicine given once a day is an option in some countries. It suits newly diagnosed cats that are otherwise healthy and have never had insulin, because it works only while the pancreas still makes some insulin. Cats on it need close follow-up with the vet.

Many diabetic cats go into remission, meaning their blood sugar stays normal without insulin. This most often happens within three to four months of starting diet changes and insulin. The chance is best when treatment starts early and blood sugar is well controlled. A cat that is not in remission after about six months will most likely need insulin for life. Remission can end, so vets usually recommend keeping the same diet and regular checkups.

A veterinary ophthalmologist can often remove diabetic cataracts surgically and restore vision in suitable dogs.

Daily care at home

Routine is the core of diabetes care. Vets recommend giving meals and insulin at the same times each day and keeping exercise steady. A sudden long run or a very active day can drop blood sugar.

Insulin is usually given only once you know your pet has eaten. Ask your vet ahead of time what to do if a meal is skipped or only partly eaten. If you are not sure whether a dose went in, most vets advise skipping it and giving the next one at the usual time. A double dose carries a much greater risk than a missed one.

Insulin is kept in the refrigerator, never in the freezer, and away from heat and sunlight, which weaken it. It comes in different strengths, and each strength needs its matching type of syringe.

Many owners keep a simple log of insulin times, food eaten, water intake, and weekly weight. A shared chart on the fridge stops two family members from both giving a dose. Blood sugar can also be checked at home with a glucose meter or a small skin sensor that reads it continuously. Home readings are often more reliable in cats, because they avoid the stress of the clinic.

Changes in thirst and urination are useful signals. If your pet starts drinking or urinating more again, tell your vet, since the treatment may need adjusting. Once the pet is stable, rechecks every few months are common.

Prevention and newly adopted pets

Not every case can be prevented, especially in dogs. Keeping a healthy weight is one of the most useful steps, and it matters most for cats. Measured meals, regular exercise, and spaying female dogs all lower the risk. If your pet needs long-term steroid medicine, ask your vet how to watch for diabetes.

Middle-aged and older pets benefit from regular checkups with blood and urine tests. These can find diabetes before the signs are obvious.

At Paw Squadron, the first stop after every rescue is the vet, and every animal gets a checkup, treatment, vaccinations, and a microchip before adoption. Diabetes can still develop later in life. If you adopt an adult or senior pet, it helps to learn its normal drinking and eating habits in the first weeks. If increased thirst lasts more than a few days, book a vet visit.

You can find more health and care guides in PawPedia, or meet the animals looking for homes on our Adoptions page.