New Insight on Insulinoma Treatment in a Pet Rat—A Case Report

SIMPLE SUMMARY: Insulinomas are tumors of the pancreas that cause hypoglycemia. They have high prevalence in ferrets, whereas in rats are a much rare finding. The available literature on spontaneous insulinomas in rats is currently scarce. The patient from our case report was presented with no obvious hypoglycemic signs, only progressive weakness of the hind limbs was noted. However, a blood exam revealed low blood glucose and a mass in the pancreas was found on the abdominal ultrasound. The patient responded well to treatment with oral dexamethasone and survived nearly 4 months in good general condition. In geriatric rats peripheral neuropathy and pituitary tumors are very common, leading to mobility disfunction. That is why insulinoma should always be considered in cases of neurological deficits in these patients. ABSTRACT: Insulinomas are insulin-producing tumors of pancreatic beta cells that cause hypoglycemia. They are extremely common in ferrets but have also been reported in guinea pigs and rats. This is a case report of an older rat with spontaneous insulinoma, which was confirmed by histopathology. The patient was presented at a regular check-up due to a chronic respiratory disease. The owner noticed progressive weakness of the hind limbs, which is quite commonly seen in older rats. A blood exam revealed hypoglycemia, which could have been associated with paraparesis. The patient responded to treatment with oral dexamethasone and was regularly monitored. It survived nearly 4 months in good general condition. The rat finally died most probably due to severe hypoglycemia caused by progression of the pancreatic tumor. This is the first report of a pet rat with insulinoma that was successfully treated with glucocorticoids.