Genetic Characterization of Coronaviruses from Domestic Ferrets, Japan

Yutaka Terada, Shohei Minami, Keita Noguchi, Hassan Y.A.H. Mahmoud, Hiroshi Shimoda, Masami Mochizuki, Yumi Une, and Ken Maeda

Author affiliations: Yamaguchi University, Yamaguchi, Japan (Y. Terada, S. Minami, K. Noguchi, H.Y.A.H. Mahmoud, H. Shimoda, K. Maeda); Kagoshima University, Kagoshima, Japan (M. Mochizuki);Azabu University, Kanagawa, Japan (Y. Une)

Abstract

We detected ferret coronaviruses in 44 (55.7%) of 79 pet ferrets tested in Japan and classified the viruses into 2 genotypes on the basis of genotype-specific PCR. Our results show that 2 ferret coronaviruses that cause feline infectious peritonitis–like disease and epizootic catarrhal enteritis are enzootic among ferrets in Japan.

An epizootic catarrhal enteritis (ECE) was first recognized in domestic ferrets (Mustelo putorius furo) in the United States in 2000 (1). The causative agent of ECE was demonstrated to be a novel ferret coronavirus (FRCoV) belonging to the genus Alphacoronavirus (1,2). Ferrets with ECE showed general clinical signs of lethargy, anorexia, and vomiting and had foul-smelling, green mucous–laden diarrhea. A systemic infection of ferrets closely resembling feline infectious peritonitis (FIP) was subsequently reported among ferrets in the United States and Europe. The causative agent was also shown to be an Alphacoronavirus, which was named ferret systemic coronavirus (FRSCV) (3,4); this virus was found to be genetically distinct from those associated with ECE and from 2 viruses assigned to different genotypes (5). Other cases of ECE and ferret infectious peritonitis have since been described in the United States and in Europe (2–4,6,7). One case of pathology-confirmed FIP-like disease has been described among domestic ferrets in Japan (8). The goal of this study was to determine the prevalence of coronavirus among domestic ferrets seen by veterinarians in various parts of Japan.

The Study

Fecal samples were collected during August 2012–July 2013 from 79 ferrets from 10 animal hospitals scattered across 5 prefectures in Japan. Most of the ferrets were brought to veterinarians for clinical signs such as diarrhea, abdominal masses, and hypergammaglobulinemia; some had signs unrelated to coronavirus infection or were asymptomatic (Table 1). The diarrhea tended to be mild, unlike with ECE, and was found in coronavirus-negative and -positive animals.