Diabetes Mellitus in our Carnivores Diabetes mellitus (DM) is due to loss or dysfunction of insulin secretion by pancreatic beta cells, diminished insulin sensitivity in tissues, or both.

 

In the dog, beta-cell loss tends to be rapid and progressive, and is usually due to immune-mediated destruction, vacuolar degeneration, or pancreatitis. In the cat, loss or dysfunction of beta cells is the result of insulin resistance, islet amyloidosis, or chronic lymphoplasmacytic pancreatitis.

 

Dogs and cats in the early stages of nonclinical DM appear healthy, have a stable weight, and are usually identified as a result of routine laboratory evaluation and do not have clinical signs of DM. We are not qualified to make a diagnosis based on the presence of clinical signs and will not advise on a diet based on the suspicion of diabetes. Therefore, it is important that there is a confirmed diagnosis by a veterinarian. Clinical signs can be used for monitoring the treatment of the pet. Pets with suspicion of DM may present weight loss, lethargy, weakness, and poor body condition. Dogs may have cataracts, and cats may accompany with a complaint of impaired jumping and abnormal gait. Some will present with systemic signs of illness due to diabetic ketosis/ ketoacidosis, such as anorexia, vomiting, dehydration, and depression.

 

DM in Dogs

Risk factors for dogs developing DM include insulin resistance caused by obesity, certain diseases (hyperadrenocorticism [HAC], hypertriglyceridemia, and hypothyroidism, dental disease, systemic infection, pancreatitis, and pregnancy/diestrus), or medications. Genetics is a suspected risk factor, and certain breeds of dogs are predisposed.

 

DM in Cats

Feline diabetes is characterized by insulin resistance and glucose intolerance but with some residual capacity to produce insulin and can be associated with profound metabolic effects on the whole body. Risk factors for cats developing DM include insulin resistance caused by obesity, certain diseases (acromegaly and kidney disease, dental disease, systemic infection, pancreatitis although not as common as in dogs, and pregnancy/diestrus), or medications. Although obesity predisposes a cat to becoming diabetic, loss of weight, and especially loss of lean body mass, is common in cats with diabetes.

 

Dietary Management of Diabetes Mellitus

Dietary therapy is important in the successful management of diabetic cats and dogs and should be used in conjunction with active monitoring from a veterinarian.

 

The primary goal of dietary therapy is to feed a diet that lessens postprandial hyperglycemia, reduces marked fluctuations of blood glucose, minimizes the demand on beta cells to produce insulin, and improves insulin sensitivity using carbohydrate restriction. One of the main advantages of carbohydrate restriction is that it allows control of hyperglycemia with lower doses of insulin, thus lessening the risk of hypoglycemia. A secondary goal of therapy is to provide a diet that helps correct obesity, normalize body weight, and optimize body weight by feeding high protein. This higher-than-average protein in the diet also helps restore and maintain loss of muscle mass, especially in cats as many diabetic cats develop sarcopenia as they age.

 

Although it is important to implement a high-protein diet in the management of diabetes as soon as possible, there are circumstances in which this should be delayed or may be inappropriate. For example, in pets with advanced CKD requiring phosphorus restriction and a reduction in dietary protein, high-protein diabetic diets may not be appropriate.

 

References:

Alexander J. German, The Growing Problem of Obesity in Dogs and Cats, The Journal of Nutrition, Volume 136, Issue 7, 1 July 2006, Pages 1940S–1946S

Peterson, Mark E., and Laura Eirmann. "Dietary management of feline endocrine disease." Veterinary Clinics: Small Animal Practice 44.4 (2014): 775-788.

Behrend, Ellen, et al. "2018 AAHA diabetes management guidelines for dogs and cats." Journal of the American Animal Hospital Association 54.1 (2018): 1-21.