Yale study suggests SARS-CoV-2 is declining in animals

SARS-CoV-2 infections in animals appear to be tapering off, according to new work from Yale researchers that combined field surveillance with laboratory studies. In a study highlighted by Yale on January 9, 2026, investigators reported no active SARS-CoV-2 infections among 889 sampled animals across 28 species, including dogs, cats, rodents, raccoons, pigs, sheep, and deer, even though they did detect other animal coronaviruses in some species. The team’s experimental work also found that white-footed mice could be infected with the original virus and Omicron, but shed less virus with Omicron and did not transmit it onward, supporting the idea that later variants may be becoming less suited to nonhuman hosts. (news.yale.edu)

Why it matters: For veterinary professionals, the findings add to a growing picture that today’s SARS-CoV-2 strains may pose less risk of establishing new animal reservoirs than earlier in the pandemic, even as human-to-animal transmission clearly occurred in prior years. That’s consistent with earlier U.S. surveillance showing companion animals usually became infected after exposure to a person with COVID-19, and with a recent JAVMA study of U.S. zoological institutions finding infections were driven primarily by human-to-animal transmission, without evidence of sustained viral evolution in zoo animals from 2020 to 2023. For clinics, shelters, and zoological medicine teams, the practical takeaway is that One Health surveillance still matters, but the immediate spillback risk from common pet-parent contact may be lower than many feared early in the pandemic. (stacks.cdc.gov)

What to watch: Watch for peer-reviewed publication of the Yale group’s newer findings, and for whether ongoing wildlife and zoo surveillance continues to show declining detection rates as SARS-CoV-2 evolves further in humans. (news.yale.edu)