The excess levels of insulin produced by these tumors drive the glucose in the blood into the cells of the body, causing a dangerously low blood glucose level, known as hypoglycemia. Not all islet cell tumors appear to be functional, however. Islet cell tumors are often found as incidental findings at autopsy of animals dying of unrelated causes. Finally, a small percentage of animals fail to show characteristic signs of hypoglycemia, or show signs that are so subtle that they are not noticed by the owner and picked up on routine blood screening for other conditions. Hypoglycemic ferrets may exhibit a wide range of clinical signs.
Weight loss appears to be a common finding in affected animals, and is occasionally the only sign.
This is an excellent reason why you should periodically weigh your pet as part of a good preventive health program. Diagnosis of islet cell tumors is fairly simple and consists primarily of measuring the blood glucose levels in the ferret, which your vet can do if you suspected this problem. Exploratory surgery in hypoglycemic but otherwise healthy ferrets should be scheduled at the earliest possible time. It is important to realize that this is only a temporary measure and rarely is effective in controlling the animal's hypoglycemia for a long period. Each time I clip toenails and clean ears, I give each ferret a good once over.