Management of Complicated Diabetes Mellitus

Diabetes mellitus is a common disease in dogs and cats that is characterized by a deficiency of the hormone insulin. Insulin helps to regulate blood sugar (“glucose”) levels by stimulating sugar uptake into the cells of the body. When insulin is deficient, blood sugar levels remain high (“hyperglycemia”) because sugar cannot enter cells and be converted to energy. Diabetic patients often have an excellent appetite, but weight loss and muscle-wasting can occur because food cannot be properly utilized by the body. The excess sugar in the blood spills over into the urine, leading to excessive urination and a drive to drink more water. The presence of sugar in the urine also predisposes diabetic patients to urinary tract infections.

Diabetes is treated with dietary modifications and daily insulin injections given under the skin, and therapy is usually life-long. The type and amount of insulin given varies from patient to patient and will sometimes be changed during the course of therapy. The appropriate type and amount of insulin are determined through regular rechecks, which can include blood glucose curves as well as submission of blood and urine samples for evaluation.

Increases in appetite, drinking, or urination can be signs that a patient’s diabetes is not well-controlled. It is important to watch for these signs and contact a veterinarian if concerns arise because a life-threatening metabolic condition called “diabetic ketoacidosis” (DKA) can occur in patients with a persistent hyperglycemia. Additionally, low blood glucose levels (“hypoglycemia”) can occur as a result of too much insulin administration. This may manifest as weakness, incoordination, trembling, collapse, and/or seizure activity. It is important to make sure that your pet has eaten a normal meal prior to insulin administration to prevent hypoglycemia. If for some reason your pet does not eat, give half of the regular dose of insulin and contact a veterinarian. If you see any signs suggestive of hypoglycemia, apply some Karo® syrup or sugar water to the gums and have your pet checked immediately by a veterinarian. Making sure that you have the appropriately-sized syringes and that you change the insulin bottle as recommended (usually once monthly) can help to prevent problems from arising.

Many dogs and cats with diabetes are well-regulated and can be easily managed through your family veterinarian. However, other concurrent disease processes, such as Cushing’s syndrome and hypothyroidism, can make regulation difficult. Our Internist can help to clarify the problem and manage multiple diseases to ensure that the highest quality of life is being maintained. Further diagnostics may be recommended to look for other diseases in poorly-regulated patients.

Even in well-regulated diabetics, long-term complications can occur, including retinal degeneration, cataract formation, and blindness. Diabetic animals are also more prone to infections, particularly of the urinary tract. Other rare complications include degeneration of the kidneys or peripheral nerves (particularly to the limbs), although these are more common in humans than in dogs and cats.

For more information on diabetes mellitus and nutritional management, please refer to: