title: Experimental inoculation of equine coronavirus into Japanese draft horses.
abstract: Recently, outbreaks associated with equine coronavirus (ECoV) have occurred in Japan and the United States. While ECoV is likely to be pathogenic to horses, it has not been shown that experimental inoculation of horses with ECoV produces clinical signs of disease. In this study, we inoculated three Japanese draft horses with an ECoV-positive diarrheic fecal sample to confirm infection after inoculation and to investigate the clinical course and virus shedding patterns of ECoV. Virus neutralization tests showed that all three horses became infected with ECoV. Two of the three horses developed clinical signs similar to those observed during ECoV outbreaks, including fever, anorexia, and gastrointestinal dysfunction. All horses excreted a large amount of virus into their feces for more than 9 days after inoculation regardless of the presence or absence of clinical signs, which suggests that feces are an important source of ECoV infection. ECoV was also detected in nasal swabs from all horses, suggesting that respiratory transmission of ECoV may occur. Both symptomatic horses developed viremia, while the asymptomatic horse did not. White blood cell counts and serum amyloid A concentrations changed relative to the clinical condition of the inoculated horses; these may be useful markers for monitoring the clinical status of horses infected with ECoV. This is the first report of induction of clinical signs of ECoV infection in horses by experimental inoculation. These clinical and virological findings should aid further investigation of the pathogenesis of ECoV.
authors.affiliation: Epizootic Research Center, Equine Research Institute, Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi, 329-0412, Japan, nemoto_manabu@epizoo.equinst.go.jp.
authors.forename: Manabu
authors.initials: M
authors.lastname: Nemoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Oue
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Morita
authors.forename: Toru
authors.initials: T
authors.lastname: Kanno
authors.forename: Yuta
authors.initials: Y
authors.lastname: Kinoshita
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Niwa
authors.forename: Takanori
authors.initials: T
authors.lastname: Ueno
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Katayama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Bannai
authors.forename: Koji
authors.initials: K
authors.lastname: Tsujimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamanaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
mesh_terms: D032761:Animal Experimentation; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D017934:Coronavirus / Q000302:isolation & purification*; D018352:Coronavirus Infections / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D005243:Feces / Q000821:virology; D006734:Horse Diseases / Q000473:pathology* / Q000821:virology*; D006736:Horses; D007564:Japan; D009297:Nasal Mucosa / Q000821:virology; D009500:Neutralization Tests; D014766:Viremia; D017201:Virus Shedding
chemical_list: D000914:Antibodies, Viral