Diabetes in Shih Tzus: Signs, Risks, and Treatment

How we researched this guide: This article is based on VCA Animal Hospitals, the Merck Veterinary Manual, the American Animal Hospital Association (AAHA) diabetes management guidelines, and PetMD. It is not a substitute for an exam. Last reviewed: September 2026.

Is your Shih Tzu drinking a lot, peeing more, and losing weight even though they seem hungry? Those are classic signs of diabetes. The good news is that diabetes in dogs can be managed, and many diabetic dogs live happy lives.

Table of Contents

Is Diabetes Common in Shih Tzus?

We could not find good evidence that Shih Tzus are at higher risk than other breeds. The Merck Veterinary Manual lists several other small breeds as predisposed, including Yorkshire Terriers, Bichon Frises, and West Highland White Terriers, but notes that any breed can be affected. Most cases occur in middle-aged dogs.

Merck lists these risk factors:

Obesity, which makes the body resist insulin
Pancreatitis, which can destroy insulin-producing cells
Cushing’s disease or long-term steroid medicines
Being an unspayed female. Merck notes that spaying is recommended for intact diabetic females to help control blood sugar.

Keeping your Shih Tzu at a healthy weight is one of the best things you can do. See our Shih Tzu feeding guide.

What Is Diabetes in Dogs?

VCA explains that diabetes mellitus happens when the pancreas does not make enough insulin. Insulin lets cells use sugar from the blood for energy. Without it, sugar builds up in the blood and spills into the urine. Most diabetic dogs have the type that needs insulin injections.

Signs of Diabetes in a Shih Tzu

VCA names four main signs:

Increased thirst
Increased urination, including accidents in the house
Weight loss
Increased appetite

Other possible signs include cloudy eyes from cataracts, low energy, and repeated urinary infections. Increased thirst can also be a sign of kidney disease, so see your vet for testing. Read our Shih Tzu kidney disease guide to learn more.

Veterinarian listening to a Shih Tzu with a stethoscope — Blood and urine tests confirm diabetes.

How Diabetes Is Diagnosed

Your vet will look for high blood sugar that stays high, plus sugar in the urine. VCA notes that dogs with normal blood sugar do not have sugar in their urine. Your vet may also run other tests to check for pancreatitis, infection, or other problems.

Treatment: Insulin, Diet, and Routine

Insulin: VCA notes that most diabetic dogs need two insulin injections a day, given with meals.
Consistent meals: the same food, same amount, at the same times each day.
Weight control: AAHA notes that obese pets may need to lose 1 to 2 percent of their body weight per week at first to help insulin work better.
Regular exercise at a steady, predictable level.
Monitoring: home blood sugar checks and regular vet visits to adjust the dose.

AAHA points out that remission is rare in dogs, so most diabetic dogs need insulin for life.

Know the signs of low blood sugar. Too much insulin, a missed meal, or extra exercise can cause blood sugar to drop too low. AAHA warns that low blood sugar can be life-threatening. PetMD lists signs such as weakness, low energy, trembling, seizures, and collapse. If you see these signs, contact your vet or an emergency clinic right away. Never give extra insulin without your vet’s advice.

Shih Tzu resting in a basket with a knitted blanket — A steady daily routine makes diabetes easier to manage.

Complications to Watch For

Cataracts: Merck notes cataracts develop frequently in dogs with poorly controlled diabetes. They can cause blindness, and some dogs are candidates for surgery.
Diabetic ketoacidosis: a dangerous condition that can develop if diabetes is untreated or poorly controlled. Vomiting, weakness, and not eating need urgent care.
Urinary tract infections, which are more common in diabetic dogs.

Shih Tzus already need careful eye care. See our Shih Tzu eye care guide.

Living With a Diabetic Shih Tzu

VCA notes that once diabetes is properly regulated, the outlook is good if treatment and monitoring stay consistent. AAHA encourages owners to lean on their veterinary team, especially in the first weeks, when the routine feels new.

Long-coated Shih Tzu lying on grass in a garden — With consistent care, many diabetic dogs enjoy a good quality of life.

Frequently Asked Questions

Are Shih Tzus prone to diabetes?

We found no strong evidence that Shih Tzus are at higher risk than other breeds. The Merck Veterinary Manual notes that any breed can be affected, most cases are in middle-aged dogs, and obesity and pancreatitis raise the risk.

What are the signs of diabetes in a Shih Tzu?

VCA lists four main signs: increased thirst, increased urination, weight loss, and increased appetite. Cloudy eyes from cataracts can also appear.

How is diabetes treated in dogs?

Most diabetic dogs need insulin injections twice a day with consistent meals. Weight control, regular exercise, and blood sugar monitoring are also important.

Can diabetes in dogs be cured?

Remission is rare in dogs, according to AAHA, so most diabetic dogs need insulin for life. With consistent treatment, the outlook is good.

What should I do if my diabetic dog seems weak or shaky?

These can be signs of low blood sugar, which can be life-threatening. Contact your vet or an emergency clinic right away. Do not give more insulin unless your vet tells you to.

Sources

This article is for general information. It is not a substitute for advice from your veterinarian. Read our medical disclaimer.