Coronavirus-associated epizootic catarrhal enteritis in ferrets

Objective—To characterize clinical signs and lesions and identify the etiologic agent associated with epizootic catarrhal enteritis in domestic ferrets. Design—Cross-sectional study. Animals—119 ferrets with epizootic diarrhea of presumed viral cause and 5 control ferrets. Procedure—Clinical records and biopsy or necropsy specimens of ferrets with presumed epizootic catarrhal enteritis were reviewed. Immunohistochemical staining for coronavirus antigen was performed on paraffin-embedded tissues from approximately 10% of affected ferrets to identify viral antigen and determine its distribution. Transmission electron microscopy was performed on fecal samples and sections of jejunum. Virus isolation studies as well as immunofluorescent tests for other similar viruses were performed. Results—Characteristic microscopic lesions consistent with intestinal coronavirus infection (vacuolar degeneration and necrosis of villus enterocytes; villus atrophy, fusion, and blunting; and lymphocytic enteritis) were consistently detected in affected ferrets. Coronavirus particles were identified in feces and jejunal enterocytes by use of transmission electron microscopy. Immunohistochemical staining of jejunal sections revealed coronavirus antigens. Antigen staining was not detected in healthy ferrets or ferrets with other gastrointestinal tract diseases. Virus isolation was unsuccessful, and other similar viruses were not detected. Conclusions and Clinical Relevance—Results strongly implicate a coronavirus as the causative agent of epizootic catarrhal enteritis in ferrets. Diagnosis may be made on the basis of a combination of historical, clinical, and microscopic findings. (J Am Vet Med Assoc 2000;217:526–530)