Managing diabetes mellitues in dogs: An overview (Sponsored by Intervet/Schering-Plough Animal Health)
May 01, 2008
Signalment and clinical signs
The average age of onset for diabetes mellitus in dogs is 7 to 9 years. Samoyeds, Australian terriers, miniature schnauzers, miniature and toy poodles, and pugs are at an increased risk for diabetes mellitus, whereas German shepherds, golden retrievers, and American Staffordshire terriers are at decreased risk for the disease.1The classic history and clinical signs typically associated with diabetes mellitus in dogs include polyuria and polydipsia, weight loss, polyphagia, and blindness due to cataracts. Physical examination findings may vary from normal to severely compromised and can be nonspecific. Dogs with diabetes mellitus can have an underweight, normal, or obese body condition. Their hydration status can also vary from normal to dehydrated. In a stable diabetic dog, hepatomegaly and cataracts are common, whereas lethargy and weakness are observed less frequently. Diabetic dogs often have concurrent disorders that influence their history, clinical signs, and physical examination findings. The most common concurrent disorders in diabetic dogs are hyperadrenocorticism, urinary tract infection, hypothyroidism, acute pancreatitis, and neoplasia.2
The diagnosis of diabetes mellitus is based on history, clinical signs, physical examination findings, and persistent hyperglycemia and glucosuria. However, because diabetic dogs are usually middle age to older animals with concurrent disorders, further diagnostics are warranted, including a complete blood count (CBC), serum biochemistry profile, complete urinalysis, and urine culture. Abdominal ultrasound and thoracic radiographs may also be warranted. Test results common in diabetic dogs include a normal CBC, and a serum biochemistry profile revealing increased alanine transaminase, aspartate aminotransferase, and alkaline phosphatase activities; lipemia; and hypercholesterolemia. The urine specific gravity may be variable, although most diabetic dogs have hypersthenuria. Glucosuria is always present in diabetic patients, and proteinuria, bacteriuria, or ketonuria may also be present. Perform a urine culture and sensitivity testing even if white blood cells are not detected in the urine sediment. Dogs with diabetes mellitus are often immunocompromised; therefore, they may have a urinary tract infection with few or no white blood cells in the urine sediment.
Diet and exercise
Treat and monitor stable diabetic patients as outpatients. You should place these patients on an appropriate diabetic diet with a high concentration of insoluble fiber and complex carbohydrates, yet limited in calories and fat. You can change from the patient's normal diet to the new diet immediately; however, if the patient is hesitant to eat the new diet (a rare problem in polyphagic diabetic dogs), mix the new diet into the old diet and gradually replace the old diet over the course of a week. The diet should contain a total daily caloric intake based on the desired body weight and should be divided into two meals offered twice a day at 12-hour intervals and just before insulin administration. Examples of such diets are Purina Veterinary Diets DCO (Nestlé Purina) or Prescription Diet w/d Canine (Hill's Pet Nutrition).
You can feed diabetic dogs the new diet regardless of weight or body condition score. Many diabetic dogs lose weight because of poor glycemic control. The new diet should improve glycemic control and ultimately result in weight gain. The diet also facilitates weight loss in diabetic and nondiabetic overweight dogs. Exercise may also promote weight loss and improve glycemic control independently of the effect on body condition, as it does in people.3
It is extremely important for clients to understand that vigorous or episodic exercise can result in adverse hypoglycemia. Therefore, you should recommend moderate and routine exercise and ask clients to alert you of any changes in the extent of exercise, which should be made gradually.