Originally published in Modern Equine Vet. Read the full story.

As people become infected with new variants of SARS-CoV-2, the organism that causes COVID-19, there is likely to be more spillover to animals. Already infections have been reported in cats, dogs and minks, among others, but clinical disease in equids has not been documented.

However, a recent series of studies showed that a small percentage of horses do test seropositive for SARS-CoV-2, but are asymptomatic, so it might only be a matter of time before equids become symptomatic.

These seropositive results came after the animals were exposed to an infected person; therefore, people should probably avoid contact with their horses if they are suffering from COVID-19, according to Nicola Pusterla, Ph.D., DACVIM, who presented the results at the 68th Annual AAEP Convention.

“In a nutshell, there is no reason to panic about SARS-CoV-2 and horses,” he said. “While horses are susceptible, they are dead-end hosts. The way they become infected is via spillover from human beings with or without clinical disease,” explained Dr. Pusterla, a professor in equine internal medicine at the University of California Davis School of Veterinary Medicine.

“It's interesting to know that populations of horses that have a lot of interactions with humans, especially those who live where we have a more contagious variant of SARS-CoV-2 [circulating] are more likely to test seropositive [than other horses],” Dr. Pusterla added.