Novel findings from a beta coronavirus outbreak on an American Miniature Horse breeding farm in upstate New York

Abstract

Summary This case report describes an outbreak and novel findings associated with a beta coronavirus (BCoV) infection that occurred on an American Miniature Horse (AMH) breeding farm in upstate New York, in January and February of 2013. Twenty‐nine AMH and one donkey were present on the farm when the outbreak occurred. One 10‐year‐old Quarter Horse mare, stabled at a separate location and owned by an employee of the farm, also tested positive. A polymerase chain reaction (PCR) assay for the detection of BCoV was performed at the Animal Health Diagnostic Center (AHDC) at Cornell on all faecal samples. The PCR assay used detects multiple beta coronaviruses, including, but not limited to, equine enteric coronavirus (ECoV). Novel findings regarding this BCoV infection in horses were recognised in this outbreak study. To the authors’ knowledge, this is the largest outbreak of BCoV described thus far in a closed herd on a single premise. The case fatality rate was 0% unlike that described in a previous outbreak of ECoV involving miniature horses and a miniature donkey (Fielding et al. 2015). The morbidity rate was lower in this outbreak than in previously described studies (Oue et al. 2013; Pusterla et al. 2013). This outbreak also demonstrated the potential for BCoV transmission via farm personnel. The duration of shedding of virus in the faeces among some asymptomatic horses in this outbreak was longer than previously described clinical cases of ECoV (Pusterla et al. 2013; Nemoto et al. 2014). This study suggests that asymptomatic animals may play a role in the maintenance of BCoV during an outbreak; therefore, the need for diagnostic testing of both clinically affected and apparently clinically normal horses on a premises followed by appropriate biosecurity and control measures.

Equine Coronavirus-Associated Colitis in Horses: A Retrospective Study

“…Although our cases were not associated with known outbreaks, ECoV should be included as a differential diagnosis for horses presenting with anorexia, fever, lethargy, and colitis, until more is known, as this organism is shed for 2e5 weeks in feces of affected horses and has been shown to cause outbreaks [2,7,9,13,20]. Thus, early identification of ECoV cases is key to implement appropriate biosecurity measures to prevent potential transmission of this disease.…”

Clinical and molecular aspects of veterinary coronaviruses

“…Mortality rates are generally low, although cases of fatality rates of 27% have been detected in American Miniature horses ( Fielding et al, 2015 ). However, a recent retrospective analysis has evidenced no fatalities in an outbreak in the same horse breed ( Goodrich et al, 2020 ).…”

Das Equine Coronavirus (ECoV) – ein aktueller Überblick

“…Tage andauern [13,16,18]. Auch asymptomatische Infektionen wurden bei einer variablen Anzahl von Pferden (4-83 %) in Beständen beobachtet [7,16].…”