INSULIN OVERDOSE IN DOGS AND CATS - 28 CASES (1986-1993)

Objective-To characterize the frequency, medical history, clinical sig ns, methods of treatment, and outcome of insulin-induced hypoglycemia and to identify predisposing factors. Design-Retrospective study. Anim als-8 dogs and 20 cats with diabetes mellitus that developed hypoglyce mia because of insulin overdose. Procedure-Medical records of dogs and cats receiving insulin for treatment of diabetes mellitus were review ed. Medical records of dogs and cats that had an episode of hypoglycem ia were reviewed in detail. Results-Overdosing of insulin was more com mon in cats than in dogs. Median weight of diabetic cats that became h ypoglycemic was significantly greater than that of the hospital popula tion of diabetic cats at diagnosis. Eighty percent of cats that became hypoglycemic were receiving insulin doses > 6 U/injection, administer ed once or twice daily. Dose and type of insulin did not correlate wit h duration or severity of hypoglycemia. In 7 of 8 dogs and 10 of 20 ca ts, management factors or concurrent medical problems were considered to be predisposing causes for insulin overdose. Two dogs and 2 cats di d not have clinical signs of hypoglycemia, despite documented low conc entrations of glucose in their blood. Clinical Implications-Diabetic c ats, especially if obese, are at greater risk of insulin overdose than are diabetic dogs. The reason for overdose may not be evident. Diabet ic dogs and cats may become hypoglycemic without developing autonomic warning signs of hypoglycemia, or these signs may not be recognized (h ypoglycemia unawareness).