Abstract

The black-footed ferret (Mustela nigripes) is endemic to prairie dog colonies in North America, and was considered extinct in the wild in 1987. However, reintroductions from assurance colonies to several states, Canada and Mexico have resulted in a few fragile wild populations despite disease and habitat obstacles. Managed breeding of about 250 genetically valuable individuals continues in five AZA-accredited institutions and at the USFWS’s National Black-Footed Ferret Conservation Center. Older non-breeding ferrets are displayed at 16 AZA facilities and other exhibits. A review of the histology archives at Northwest ZooPath and reports from other institutions by the Species Survival Plan SSP pathologist (MMG) was performed for those cases submitted between 2000 and 2017, and represented 210 ferrets from 16 institutions. Inflammatory/infectious disease (62%), deposition disorders (41%), neoplasia (27%), degenerative diseases (20%) and perinatal death (stillborn to 1 day) were the most common categories, necessitating euthanasia in 37% of the cases. Of the infectious diseases (74), bacterial infections (68%) were most common, followed by intestinal coccidiosis (23%). Inflammatory lesions of undetermined cause were identified in 55 ferrets, primarily in the hepatobiliary and enteric systems. Reactive systemic amyloidosis, for which the species is predisposed, was the predominant deposition disorder (97%). Neoplastic processes included benign and malignant tumors of the biliary system (28%), adrenal cortical tumors (11%) and anal sac adenocarcinoma (9%). Of the degenerative diseases, chronic renal disease/nephrosclerosis was most common (78%), and usually seen concurrently with glomerular amyloidosis. Trends were similar to previously documented diseases of this species, with few exceptions: renal tumors were less prevalent, and no toxoplasmosis, distemper or plague were diagnosed. New and probably rare cases included mycobacterial lymphadenitis (1) and disseminated encephalitozoonosis (1).

Acknowledgments

The authors thank Cathy Minogue and Christie Buie of Northwest ZooPath for data and literature retrieval.

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