Diabetes Mellitus in Cats

Feline Diabetes or Diabetes Mellitus (DM)

DIABETES – AN OVERVIEW

When the digestive system breaks down food, carbohydrates are converted into simple sugars such as glucose. This  glucose is absorbed into the blood where it is transported around the body. Insulin, which is produced in the pancreas, helps move the glucose into the cells of the body where it is converted into fuel (energy).

Diabetes mellitus is a disease caused either by:

• A lack of insulin, or
• The body’s inadequate response to insulin

Whether insulin is insufficient, or the body responds inadequately to insulin, glucose is unable to enter cells; therefore, muscles and organs do not get the fuel needed to function, and blood glucose levels remain abnormally high in the bloodstream. Over time high levels of glucose in the blood can cause serious health problems.

DIABETES AND RISK FACTORS

Depending on the origin of diabetes, the condition is divided into two categories:

Type 1 or “Juvenile Diabetes” or “Insulin-dependent Diabetes”

Type 1 diabetes is caused by the destruction of beta cells in the pancreas. Because the destruction of the cells is not reversible, the animal must be treated with an external source of insulin. Both cats and dogs can suffer from Type 1 diabetes.

Type 2 or “Adult-onset Diabetes” or “Non-insulin-dependent Diabetes”

Type 2 diabetes is characterized by high blood sugar due to the body being resistant to insulin and a relative lack of insulin. Type 2 diabetes is found in cats, but not in dogs.

PREDISPOSITION TO DIABETES

Diabetes, and Type 2 diabetes specifically, is a common disorder in cats. It is estimated that diabetes or diabetes mellitus (DM) affects between 0.2 – 1% of cats in the general population.

The condition can be common in:

• Overweight cats
• Physically inactive cats
• Neutered male cats
• Middle-aged and senior cats
• Cats that exclusively eat a high carbohydrate diet
• Cats that have been on glucocorticoid (steroid) therapy

Pancreatitis and metabolic diseases, such as hyperthyroidism are also risk factors. Genetics can also play a role in diabetes. Burmese cats seem to be at a higher overall risk.

CLINICAL SIGNS OF DIABETES IN CATS

A diabetic cat may behave as if it is constantly hungry since the cells are not producing fuel. However, it may also appear malnourished despite overeating since the cells are unable absorb glucose.

Signs may include:

• Weight loss despite increased appetite
• Excessive thirst and urination
• Dehydration
• Walking or standing in a plantigrade posture (“down in the hocks”)

DIAGNOSIS OF DIABETES IN CATS

Diabetes is diagnosed by the presence of clinical signs as well as high glucose concentrations in the blood and urine. If your cat is anxious at veterinary visits (“stress hyperglycemia”), your veterinarian may also measure fructosamine, a marker of chronic DM that is not affected by stress like glucose is.

TREATMENT AND MANAGEMENT

The main treatment of DM is insulin. Your veterinary team will teach you how to inject the insulin; with time and experience, both you and your cat will adapt to these injections very well.

Your veterinarian will monitor your cat’s response to treatment by performing blood glucose curves and measuring fructosamine periodically.

Your veterinarian may also recommend a veterinary diet restricted in carbohydrates, which has been shown to improve control of blood glucose levels. If your cat is overweight, your veterinarian may first institute a weight loss program; managed weight loss in overweight diabetic cats will likely help the cat maintain steadier glucose levels.

PROGNOSIS

While there is no cure for feline DM, this disease can be managed fairly well when you work with your veterinary healthcare team. Cats with well-controlled diabetes can live many years of high-quality life.