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Animals : an open access journal from MDPI2022; 12(5); 614; doi: 10.3390/ani12050614

Investigation of the Role of Healthy and Sick Equids in the COVID-19 Pandemic through Serological and Molecular Testing.

Abstract: More and more studies are reporting on the natural transmission of SARS-CoV-2 between humans with COVID-19 and their companion animals (dogs and cats). While horses are apparently susceptible to SARS-CoV-2 infection based on the homology between the human and the equine ACE-2 receptor, no clinical or subclinical infection has yet been reported in the equine species. To investigate the possible clinical role of SARS-CoV-2 in equids, nasal secretions from 667 horses with acute onset of fever and respiratory signs were tested for the presence of SARS-CoV-2 by qPCR. The samples were collected from January to December of 2020 and submitted to a commercial molecular diagnostic laboratory for the detection of common respiratory pathogens (equine influenza virus, equine herpesvirus-1/-4, equine rhinitis A and B virus, subspecies ). An additional 633 serum samples were tested for antibodies to SARS-CoV-2 using an ELISA targeting the receptor-binding domain of the spike protein. The serum samples were collected from a cohort of 587 healthy racing Thoroughbreds in California after track personnel tested qPCR-positive for SARS-CoV-2. While 241/667 (36%) equids with fever and respiratory 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 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, horses can act as incidental hosts and experience silent infection following spillover from humans with COVID-19. SARS-CoV-2-infected humans should avoid close contact with equids during the time of their illness.
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Publication Date: 2022-02-28 PubMed ID: 35268183PubMed Central: PMC8909032DOI: 10.3390/ani12050614Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research article explores whether horses can host and subsequently transmit the SARS-CoV-2 virus, which is responsible for COVID-19 in humans. The study, conducted in 2020, found no evidence of horses developing clinical SARS-CoV-2 infection, but a small percentage showed signs of silent infection, suggesting possible transmission from humans.

Research Methodology

  • The researchers performed an extensive survey, testing nasal secretions from 667 horses, all of which had symptoms of fever and respiratory distress. The goal was to detect the presence of the SARS-CoV-2 virus using a method known as qPCR (Quantitative polymerase chain reaction).
  • The nasal secretions were collected throughout 2020 and were also tested for common respiratory pathogens such as the equine influenza virus, equine herpesvirus-1/-4, equine rhinitis A and B virus.
  • Blood serum samples from an additional 633 horses were tested for antibodies to SARS-CoV-2 using ELISA (Enzyme-Linked Immunosorbent Assay).
  • The serum samples were collected from a cohort of 587 healthy racing Thoroughbreds in California after track personnel had tested qPCR-positive for SARS-CoV-2.

Research Findings

  • The study found that 36% of the horses with fever and respiratory signs were qPCR-positive for at least one of the common respiratory pathogens, but not a single horse tested positive for SARS-CoV-2.
  • A slight 5.9% of the tested Thoroughbred horses had detectable antibodies to SARS-CoV-2, suggesting they had been exposed to the virus but did not develop a clinical infection.
  • The researchers concluded that while horses don’t seem to develop clinical SARS-CoV-2 infection, they can act as incidental hosts and experience silent infection following spillover from SARS-CoV-2 infected humans.

Implications

  • While the study does not provide evidence that horses can contract or show symptoms of COVID-19, the presence of SARS-CoV-2 antibodies in some horses suggests they can get infected, likely from humans. This means that while the horses themselves may not get ill, they could potentially serve as a source of transmission to other humans.
  • The findings indicate that humans who have tested positive for SARS-CoV-2 should avoid close contact with equids to prevent potential transmission.

Cite This Article

APA
Lawton KOY, Arthur RM, Moeller BC, Barnum S, Pusterla N. (2022). Investigation of the Role of Healthy and Sick Equids in the COVID-19 Pandemic through Serological and Molecular Testing. Animals (Basel), 12(5), 614. https://doi.org/10.3390/ani12050614

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 12
Issue: 5
PII: 614

Researcher Affiliations

Lawton, Kaila O Y
  • Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Arthur, Rick M
  • School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Moeller, Benjamin C
  • KL Maddy Equine Analytical Chemistry Laboratory, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
  • Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Barnum, Samantha
  • Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Pusterla, Nicola
  • Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.

Grant Funding

  • 2021 / Boehringer Ingelheim Animal Health
  • 2021 / Center for Equine Health, School of Veterinary Medicine, University of California, Davis, California, USA

Conflict of Interest Statement

The authors declare no conflict of interest.

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Citations

This article has been cited 10 times.
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