DIAGNOSIS AND MANAGEMENT OF INSULIN-RESISTANCE IN DOGS AND CATS WITH DIABETES-MELLITUS

Diabetes mellitus is a common endocrine disorder in dogs and cats. The value of insulin in the management of canine and feline diabetes is w ell-established.(17, 44, 47, 50) Both cats and dogs with diabetes, how ever, occasionally develop resistance to the action of insulin during treatment.(31, 47, 68) Characteristically, hyperglycemia, glycosuria, and clinical signs of diabetes (i.e., polyuria, polydipsia, and polyph agia) persist in these animals despite gradually increasing daily insu lin doses. In most diabetic dogs and cats good glycemic control (i.e., daily blood glucose concentrations between 100 and 250 mg/dL) can be achieved by twice daily administration of an intermediate-acting insul in preparation (i.e., NPH or Lente) at doses of <1.0 U/kg per injectio n. In many diabetic cats, adequate glycemic control also can be achiev ed by once or twice daily administration of a long-acting insulin prep aration (e.g., Ultralente insulin) at doses of <1.5 U/kg body weight p er injection. Clinical insulin resistance should be suspected in any d og or cat in which marked hyperglycemia persists throughout the day de spite insulin doses of >1.5 U/kg per injection. Insulin resistance als o should be suspected when large doses of insulin (i.e., >2.2 U/kg per injection) are necessary to maintain adequate glycemic control. In cl inical setting, it may be difficult to determine the underlying cause for insulin resistance which makes management difficult. This article reviews the known causes for insulin resistance in dogs and cats and o utlines recommendations for diagnosis and management of these animals.