This paper attempts to examine the current state of diagnostic and clinical management of insulinoma in humans, in dogs, and in ferrets, with the purpose of determining which procedures in human medicine might be applicable to the different species. A case history of a ferret is given, demonstrating the need for advancement in the veterinary medical approach to this disease. Insulinoma, or pancreatic islet beta cell tumor, is a commonly seen endocrine neoplasm of middle-aged ferrets. It is less common in dogs, and rather rare in cats. It is fairly rare in human medicine, as the incidence is overwhelmingly of benign pancreatic hyperplasia.