Diabetes Problems in Dogs

Definition of Diabetes

• Diabetes mellitus arises from either a deficiency of or an insensitivity to insulin. Insulin is a hormone produced by the pancreas, and it controls the body's glucose level. Glucose is the main type of blood sugar and a major source of cellular energy. It mainly comes from the food your dog eats. Insulin regulates the liver's production of glucose and triggers the body to store any excess not needed for energy. In diabetes, the body's insulin level is insufficient to stop the liver from producing glucose or stimulate the body to store the excess.

Diabetes Signs

• Without the ability to shut off glucose production or enable glucose storage, the glucose levels in the blood increase to the point where the kidneys let the excess glucose leak into the urine. This excess glucose attracts water and creates a larger than normal volume of urine which, in turn, creates excessive thirst and water consumption by the animal. Therefore, the first clinical signs that your dog has developed diabetes are excessive drinking (polydipsia) and excessive urination (polyuria). Your dog may also exhibit a sudden weight loss resulting from a breakdown of protein and fat to produce glucose and ketones in the liver. (Ketones are organic compounds produced when body fat is broken down for energy. This reaction occurs when there is insufficient insulin in the body to transport glucose from the blood stream to the cells.) Other signs may include increased appetite, an intolerance to exercise, the formation of cataracts, and persistent recurring infections.

Somogyi Effect

• The Somogyi effect occurs when a dog's blood glucose level suddenly swings sharply upward (hyperglycemia) after a period of low blood glucose (hypoglycemia). The hypoglycemic episode triggers the release of hormones that signal the liver to release more glucose into the system. Somogyi can be set into motion by administration of an insulin dose that is too high, or it can result from a swing in blood glucose levels during sleep. A dog suspected of experiencing Somogyi may initially become hungry, restless or lethargic, then exhibit first polydypsia (excess thirst) then polyruia (excess urination) after the body reacts by releasing more glucose into the blood.
  A hyperglycemic episode may last for a few days. The dog's veterinarian will need to monitor blood glucose for a short period of time following the episode in order to definitively diagnose Somogyi.

Cataracts

• Cataracts occur more often in diabetic dogs than in diabetic cats. Excess glucose triggers an influx of water into the lens of the eye and a breakdown of the lens structure, creating a cloudiness that causes loss of vision. Diabetic retinopathy, resulting from changes in the retinal blood vessels, occurs, but rarely.

Diabetes Treatments

• Insulin is the most widely used form of treatment for diabetes. It is specially prepared for slow absorption by the body and administered by subcutaneous injection (or, underneath the skin) because insulin is a protein and will be broken down by the digestive system if administered in tablet form. Insulin is fragile and must be handled with care---thoroughly mixed prior to administration and never frozen, heated, or shaken too hard. Injections are given either once or twice a day, depending on the particular dog's needs. A University of Pennsylvania study found that most dogs do better on twice-daily dosing. Certain prescription diets, as recommended by a veterinarian, can effectively supplement insulin therapy.

Conclusion

• Canine diabetes is common and can be managed with proper and early diagnosis and appropriate treatment, including regular insulin therapy. Maintaining a positive attitude and good communication with your veterinarian will keep your dog healthy and happy for years.