Insulinoma in Cats

This chapter discusses pathogenesis, classical signs, diagnosis, treatment, and prognosis for insulinoma in cats. Insulinomas are functional tumors of the pancreatic beta cells that autonomously synthesize and secrete insulin, even in the face of hypoglycemia. This predisposes animals to hypoglycemic crises during fasting and exercise. These tumors retain some responsiveness to many of the normal stimuli for insulin secretion, but demonstrate an exaggerated response. Therefore, animals with insulinoma are at risk of hypoglycemia after eating or with the administration of glucose containing intravenous fluids. Clinical signs are generally present for weeks to months prior to investigation. They typically included seizures, lethargy, weakness, muscle twitching, and collapse, although inappetence, diarrhea, and weight loss have also been reported Hematological abnormalities have rarely been reported in cases of insulinoma; those documented include anemia and mild thrombocytopenia. The prognosis for cats with insulinoma appears highly variable.