Diabetes in Dogs: Signs, Treatment and Daily Care

What it is

Diabetes mellitus is a disorder of blood sugar control. Insulin, made in the pancreas, moves sugar from the blood into the body's cells. When a dog does not make enough insulin, or the tissues resist it, sugar builds up in the blood while the cells starve.

That explains the classic signs. The body breaks down fat and protein for energy, so the dog loses weight despite eating more. Excess sugar spills into the urine and pulls water with it, so the dog drinks and pees more. VCA describes type I, with near-total loss of insulin-producing cells, as the most common type in dogs, and these dogs need insulin injections.

Long-term high blood sugar can cause cataracts, which can lead to blindness, as well as urinary tract infections and an enlarged liver. The most dangerous complication is diabetic ketoacidosis (DKA), when the blood turns too acidic. It is a medical emergency, with signs that include weakness, lethargy, poor appetite, vomiting and dehydration.

Causes and risk factors

What you can do at home

Daily care is a routine. Most diabetic dogs need insulin injections under the skin, typically twice a day with meals, and your vet will teach you how. Feed the same food in the same amount at the same times every day, and keep exercise moderate and consistent, because sudden changes can swing blood sugar.

Never change the insulin amount or type, or skip a dose, without checking with your vet. If your dog does not eat, call your vet that day for instructions rather than guessing. Your vet may also have you check glucose at home with a meter or monitor, and the AKC suggests keeping urine ketone strips on hand and calling an emergency vet if they test positive. Ask whether that suits your dog.

Know the signs of low blood sugar after insulin: weakness, poor coordination, confusion, tremors, seizures or collapse. These are emergencies. Ask your vet for a low-blood-sugar plan when insulin is first prescribed, and follow the plan your vet gives you. Cornell's general advice is to apply corn syrup to your dog's gums and then contact your vet immediately for further directions. Keep your vet's number and the nearest emergency clinic's handy.

Keep a simple log of thirst, appetite, weight and energy, and bring it to checkups.

What happens at the vet

Diagnosis is based on the typical signs, persistently high blood sugar and sugar in the urine. Your vet will also run blood work and a urine test to look for conditions that go along with diabetes or make it harder to control, such as pancreatitis, urinary tract infection, Cushing's disease and an underactive thyroid. Stress can raise blood sugar temporarily, so a test called fructosamine can help tell stress from true diabetes.

Treatment centers on insulin, a consistent diet and weight control if needed. After starting insulin, your vet will track blood sugar over a day in a test called a glucose curve and adjust treatment. VCA says it can take a month or more to get a dog well regulated, and early visits are frequent.

Higher-fiber diets may help, though Cornell says plenty of dogs manage well on any complete, balanced food they enjoy, as long as meal times and amounts stay consistent. Merck recommends spaying females that are not already spayed. DKA needs hospital care, sometimes for several days.

The outlook is good for many dogs. Cornell says dogs usually need lifelong insulin but can have a good quality of life with an owner's commitment and close vet partnership.

Prevention

There is no guaranteed way to prevent diabetes, since age, genetics and the immune system all play a part. You can still reduce some risks.

Keep your dog at a healthy weight, because obesity contributes to insulin resistance and to pancreatitis. Our guide on how to tell if your dog is overweight can help. Avoid feeding fatty scraps and treat pancreatitis promptly, since repeated pancreatitis can damage the cells that make insulin. See pancreatitis in dogs.

Spaying is worth discussing with your vet. Unspayed females are at higher risk, and hormones during heat and pregnancy can cause insulin resistance. Use steroid medicines only as your vet directs, and mention any long-term steroid use at checkups.

The best protection is early detection. Report increased thirst, more frequent urination or weight loss despite a good appetite as soon as you notice them, since earlier diagnosis and treatment give a better chance of a normal life, according to the AKC. Regular wellness visits with bloodwork help catch problems before a crisis.