Feline diabetes mellitus by Claudia Reusch

Diabetes mellitus is a common endocrinopathy in cats.

The incidence of the disease is increasing, most likely due to an increase in the occurrence of risk factors, such as obesity, physical inactivity, old age, male gender, being neutered, glucocorticoid and progestin administration.

The most important risk factor is obesity and it has been shown that obese cats are 4 times more likely to develop diabetes than optimal weight cats.

It is important to note that although obesity induces insulin resistance not all obese cats develop diabetes.

Diabetes typically occurs in middle-aged to old cats. There is a strong sex predilection since approximately 70% of diabetic cats are male. Approximately 60% of diabetic cats are overweight, 35% are normal weight and 5% underweight.

Most diabetic cats show the classical signs of diabetes, namely PU/PD (polyuria, polydipsia),

polyphagia and weight loss. 

About 10% of diabetic cats have overt signs of diabetic neuropathy, manifested as hindlimb weakness, decreased ability to jump and plantigrade posture. Lethargy and a dry, unkempt haircoat are often present, whilst physical examination may reveal hepatomegaly.

Cats with complicated diabetes (diabetic ketoacidosis, hyperosmolar non-ketotic syndrome) present with lethargy, anorexia, reduced water intake and vomiting.

Diabetes is diagnosed on the basis of clinical symptoms, persistent hyperglycemia and glucosuria and fructosamine blood concentration, rather than glucose, as it reflects the mean blood glucose concentration of the preceding 1-2 weeks.

Any concurrent disease may worsen insulin resistance and will hinder treatment success. In some cases bacterial urinary tract infection is present and pancreatitis is frequently associated with diabetes.