OAHN Equine Network Project: Investigation of a respiratory disease outbreak in the Ontario harness industry and the economic impact on industry participants

Project Lead: Dr. Luis Arroyo (OVC)

Collaborators:  Dr. Alison Moore (OMAFRA)

To view the full report, please download the PDF here: https://www.oahn.ca/wp-content/uploads/2021/12/OAHN-Project-Investigation-of-a-respiratory-disease-outbreak-fin.pdf

In July 2020, a respiratory outbreak occurred in Ontario’s southwestern harness racing industry. Veterinarians reported horses with high fevers, nasal discharge and cough. A virus was suspected given the rapid progression through a given barn and the clinical signs, and the Ontario Animal Health Network (OAHN)– Equine Network was contacted to help determine the cause.  Equine influenza virus (EIV) and equine rhinitis virus A (ERAV) were identified as the main etiologic agents.  Horses that had positive serological titres for EIV were negative on EIV PCR testing suggesting protection.  EIV and ERAV exposure / infection seemed to have a negative impact on performance. Costs associated with treatment and lost training days also highlighted the impact of viral respiratory infection on this industry.  These results could be used by veterinarians to support biosecurity practices, regular vaccination against EIV, continued surveillance of circulating EIV strains and ERAV exposure and support for future development and availability of ERAV vaccination.