Keys to managing, canine diabetes mellitus
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Diabetes mellitus is a complex disease, and managing it is equally complex. Treatment of diabetes mellitus in dogs typically
includes insulin therapy, an appropriate diet, and an exercise regimen, all of which must be constantly monitored and adjusted
throughout the patient's lifetime. Communicating clearly with clients and preparing them for the need to monitor and modify
treatment is vital for successfully treating a diabetic dog. Clients must be committed to extensive care, monitoring, and
frequent office visits. They must understand that these steps are necessary—not because you cannot provide optimal care—rather,
this is simply the nature of the disease. If clients know at the onset that the dose of insulin is likely to change several
times a year and that their dog will have well-regulated periods mixed with periods of suboptimal regulation, feelings of
frustration they might have down the road will be replaced with understanding and patience. All of these considerations contribute
to effective treatment for the patient and a long-lasting, productive relationship between you and the client.
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.1
The 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
Diagnosis
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.
