Hypoglycaemic crisis induced by non-islet cell tumours in two dogs

Two dogs were admitted for the diagnosis and treatment of neoplasia (a hepatic and a mammary tumour, respectively), lethargy, quadriparesis and abnormal mentation with hypoglycaemia. The blood analyses showed severe hypoglycaemia (1.32 and 1.60 mmol/l, respectively). Although prompt treatment, including intravenous administration of dextrose, was initiated, the blood glucose concentrations were not restored to a normal range. After the diagnostic procedures, no aetiology other than the hepatic tumour identified by the abdominal radiography and ultrasonography, and a mammary tumour that might have caused the hypoglycaemia, were identified. Because there was a high suspicion of non-islet cell tumour-induced hypoglycaemia as a paraneoplastic syndrome, the dogs underwent a hepatic lobectomy and total mastectomy with an ovariohysterectomy, respectively. Within 12 hours after surgery, the blood glucose concentrations of both cases had normalised, even without the administration of dextrose. The histopathological examinations identified a hepatocellular adenoma and a mammary carcinoma, respectively. The endocrine analysis of the serum at admission revealed low serum insulin concentrations (< 1.44 pmol/l) and high serum concentrations of insulin-like growth factor 2 in both dogs. Therefore, the diagnosis in both dogs was confirmed to be non-islet cell tumour-induced hypoglycaemia. Both dogs remained alive without the recurrence of hypoglycaemia 24 months later. Previously, the administration of intravenous dextrose has been considered as the initial treatment in dogs with hypoglycaemia; however, this can temporarily ameliorate the clinical signs related to the non-islet cell tumour-induced hypoglycaemia and help the anaesthesia for the surgical tumour resection as an emergency. Therefore, the definitive treatment of non-islet cell tumour-induced hypoglycaemia might be rapid surgical intervention, which can be associated with good prognosis in dogs with severe non-islet cell tumour-induced hypoglycaemia.