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.