enzyme-linked immunosorbent assay targeting the receptor-binding domain of the spike protein. The se- rum samples were collected in 2020 from a cohort of 587 racing Thoroughbreds in California after track personnel tested qPCR-positive for SARS-CoV-2.
3. Results and Discussion
While 241/667 (36%) equids with fever and respira- tory signs tested qPCR-positive for at least one of the common respiratory pathogens, not a single horse tested qPCR-positive for SARS-CoV-2. Amongst the healthy racing Thoroughbreds, 35/587 (5.9%) horses had detectable antibodies to SARS-CoV-2. Similar to dogs and cats, horses do not seem to develop clinical SARS-CoV-2 infection.However, horsesmay act as in- cidental host and experience silent infection following spillover fromhumans with COVID-19.
MEDICINE I: DRUGS, DISEASE SURVEILLANCE, AND DISASTERS Acknowledgments
Funding Sources This study was funded by an Advancement in Equine Research Award from Boehringer Ingelheim Animal Health and by the Center for Equine Health, School of Veterinary Medicine, University of California, Davis, with additional contributions from public and private donors.
Declaration of Ethics
The Authors have adhered to the Principles of Veteri- naryMedical Ethics of theAVMA.
Conflict of Interest The Authors have no conflicts of interest.