21 May 2020
Review of current knowledge of human coronavirus in animals questions assumption that domestic pets or livestock are unable to transmit the virus.
John Bonner
Job Title
Vets in the US are calling for research into whether domestic animals may be susceptible to the COVID‑19 agent and what clinical signs can reliably be used to identify an infected animal.
A review of current knowledge of human coronavirus in animals has been published in the journal Vector-Borne and Zoonotic Diseases by a team led by Tracey McNamara, professor of pathology at the Western University College of Veterinary Medicine, Pomona, California.
In it, she argued grounds exist to question the widespread assumption that the human pandemic virus cannot be transmitted by domestic pets or livestock.
If other species provide a reservoir of infection, significant implications could arise for human health, the safety and viability of the food supply chain, and even national security, she said.
Evidence exists that cats can be infected by human coronavirus, and can go on to show both respiratory and enteric signs. Ferrets and big cats kept in zoological collections have also been found to harbour the virus.
But only limited information exists on what happens to dogs when they are exposed to the pathogen.
Veterinary practitioners and other professions with close contacts with domestic and wild animals will play an important surveillance role in identifying whether dogs or other mammalian species can either be infected, or become passive carriers of the virus.
The paper suggested creating a simple surveillance form listing potential clinical signs that can be quickly reported to a central data collection site.
Prof McNamara is noted for her work on the spread on West Nile fever virus in wild birds, horses and humans in the US during the 1990s.
She said public health officials in the US and abroad need to understand the main lesson learned during that outbreak of a similarly contagious zoonotic virus – “to expect the unexpected”.
“With regards to SARS-CoV-2 in animals, this admonition seems to have been forgotten,” she said.
“Anecdotal information and assumptions are no substitute for stringent studies. Absence of evidence is not the same thing as evidence of absence.”
