Diabetes Mellitus in pets - Symptoms, diagnosis and treatment

Diabetes mellitus is a chronic condition in which the bodies of dogs and cats fail to produce enough insulin or do not respond to it properly. This causes blood sugar levels to rise, leading to various health problems. Both dogs and cats can develop diabetes, although the condition differs in progression and treatment between the two species. 

In this article, we discuss the causes, symptoms, diagnosis, and treatment of diabetes mellitus in pets.

What is diabetes mellitus?

Diabetes mellitus is caused by a lack of insulin or by reduced sensitivity of the body to insulin. Insulin is a hormone that allows glucose to move from the blood into the cells to be used as an energy source. With a deficiency or insensitivity, blood sugar levels rise (hyperglycemia).

Causes and risk factors

In dogs, diabetes is often caused by destruction of the insulin-producing cells in the pancreas (type 1 diabetes). In cats, it is usually a matter of insulin resistance (type 2 diabetes), similar to diabetes in humans.

Important risk factors include:

• Obesity (especially in cats)
• Hormonal disorders (such as Cushing's disease or heat in intact female dogs)
• Chronic pancreatitis
• Genetic predisposition
• Use of corticosteroids

Symptoms in dogs and cats

In dogs:

• Increased drinking and urination
• Increased appetite, yet weight loss
• Lethargy
• Sometimes cataracts due to high blood sugar levels

In cats:

• Similar symptoms: increased drinking, urination, and weight loss
• Hind limb weakness due to nerve damage (diabetic neuropathy)
• Poor coat condition
• Sometimes vomiting and reduced appetite

Diagnosis of diabetes mellitus

The diagnosis is made through:

• Blood tests: elevated glucose levels and sometimes elevated fructosamine
• Urine tests: presence of glucose and sometimes ketones
• Clinical symptoms combined with the above laboratory findings confirm the diagnosis

Treatment of diabetes mellitus

Insulin therapy

The basic treatment for dogs and cats is the administration of insulin. This is usually given twice daily via a subcutaneous injection. The type and dosage are tailored to the individual animal and regularly monitored. In cats, an oral treatment with an SGLT-2 inhibitor has also recently become available, which removes excess glucose through the urine.

Diet and lifestyle

An adjusted diet supports treatment:

• In dogs: high-fiber food that stabilizes blood sugar levels
• In cats: high-protein, low-carbohydrate diet
• Adequate exercise and strict weight control are essential, especially in overweight cats

Monitoring and follow-up

Regular check-ups are crucial for adjusting the insulin dosage:

• Blood glucose curves at the veterinarian
• Fructosamine levels as a measure of longer-term control
• Some owners measure blood glucose at home themselves, via an ear prick or with a sensor placed on the skin that stays in place for 1-2 weeks

For the oral treatment in cats, the urine is regularly checked for the presence of ketones.

Recovery and prognosis

With the right treatment, dogs and cats with diabetes can maintain a good quality of life. In cats, diabetes can sometimes go into remission with timely treatment and weight loss. In dogs, insulin treatment usually remains necessary for life. Early diagnosis and careful follow-up increase the chances of stable regulation.

Want to know more?

Read more about our services in internal medicine and endocrinology. Our specialized veterinarians at Nesto have extensive experience diagnosing and treating diabetes mellitus and support you and your pet with long-term care and management.

Frequently asked questions (FAQ)

What is diabetes mellitus in pets?

A metabolic disease in which the body produces too little insulin or is insensitive to it.

Which animals most often get diabetes?

Mainly older, overweight cats and small to medium-sized dog breeds.

How is diabetes diagnosed?

With blood and urine tests combined with typical symptoms.

How is diabetes treated?

With insulin injections, an SGLT-2 inhibitor, an adjusted diet, and regular check-ups.

Can my cat be cured of diabetes?

Cats can sometimes go into remission, while dogs usually need insulin for life.