Ferrets have become more popular as household pets and as animal models in biomedical research in the past 2 decades. The average life span of ferrets is about 5-11 years with onset of geriatric diseases between 3-4 years including endocrinopathies, neoplasia, gastrointestinal diseases, cardiomyopathy, splenomegaly, renal diseases, dental diseases, and cataract. Endocrinopathies are the most common noninfectious disease affecting middle-aged and older ferrets. Spontaneous neoplasms affecting the endocrine system of ferrets appear to be increasing in prevalence with a preponderance toward proliferative lesions in the adrenal cortex and pancreatic islet cells. Diet, gonadectomy, and genetics may predispose ferrets to an increased incidence of these endocrinopathies. These functional proliferative lesions cause hypersecretion of hormones that alter the physiology and metabolism of the affected ferrets resulting in a wide range of clinical manifestations. However, there is an apparent dearth of information available in the literature about the causal relationship between aging and neoplasia in ferrets. This review provides a comprehensive overview of the anatomy and physiology of endocrine organs, disease incidence, age at diagnosis, clinical signs, pathology, and molecular markers available for diagnosis of various endocrine disorders in ferrets.Keywords adrenal-associated endocrinopathy; adrenocortical neoplasm; aging; cysts; diabetes mellitus; endocrinopathies; endocrine tumors; estrogen-induced anemia; ferret; gonadectomy; insulinoma; islet cell tumor; multiple endocrine neoplasia; neuroblastoma; ovary; pancreatic polypeptidoma; parathyroid; pheochromocytoma; pituitary; review; teratoma; testis; thyroid The domestic ferret Mustela putorius furo, like the skunk, mink, weasel, stoat, otter, and badger, is a carnivorous mammal that belongs to the Mustelidae family. Ferrets were domesticated more than 2000 years ago and were primarily used for hunting rabbits and for fur production in Europe. Introduced in 1875, ferrets are considered companion animals in the United States. Approximately, 7-10 million ferrets are maintained as household pets in the United States. 3,36 In 1882, ferrets were introduced in New Zealand to control the Reprints and permission: sagepub.com/journalsPermissions.nav Corresponding Author: J. G. Fox, Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. jgfox@mit.edu. Supplemental material for this article is available on the Veterinary Pathology website at http://vet.sagepub.com/supplemental. Declaration of Conflicting Interests:The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. HHS Public AccessAuthor manuscript Vet Pathol. Author manuscript; available in PMC 2017 April 20. Author Manuscript Author ManuscriptAuthor Manuscript Author Manuscriptburgeoning European rabbit population are now considered feral animals and they play an important role in the t...