Many Animal Species May Be Vulnerable to SARS-CoV-2

Researchers hope study results will help protect at-risk species.

Western lowland gorilla
The Western lowland gorilla is predicted to be at very high risk of infection by SARS-CoV-2.

Skip Brown / Smithsonian’s National Zoo and Conservation Biology Institute

Humans aren't the only species that may be susceptible to SARS-CoV-2, the coronavirus that causes COVID-19, reports a new study from the University of California, Davis.

Using genomic analysis, an international team of researchers focused on angiotensin converting enzyme-2, or ACE2, a protein that is found on many cells and tissues. In humans, 25 of the amino acids in ACE2 are key for the virus to infect cells. Scientists compared ACE2 in 410 different vertebrate species, including amphibians, birds, fish, mammals, and reptiles.

They modeled predicted protein structure of those amino acid sequences along with the SARS-CoV-2 spike protein to analyze the number of those amino acids found in the ACE2 protein of the various species.

Animals that had all 25 amino acids matching the human protein are predicted to have the highest risk for contracting the virus with the risk predicted to decrease the more the ACE2 differs from humans, researchers said.

The results were published in the journal Proceedings of the National Academy of Sciences.

“The data provide an important starting point for identifying vulnerable and threatened animal populations at risk of SARS-CoV-2 infection,” Harris Lewin, lead author for the study and a distinguished professor of evolution and ecology at UC Davis, said in a statement. “We hope it inspires practices that protect both animal and human health during the pandemic.”

Endangered Species and Household Pets

some of the animals predicted to be at high risk of infection
Old World primates and great apes are predicted to be at high risk of infection.  Matt Verdolivo / UC Davis

Many of species potentially susceptible to the virus face dwindling population numbers. The Western lowland gorilla, Sumatran orangutan, and Northern white-cheeked gibbon are all critically endangered, according to the International Union for the Conservation of Nature (IUCN) Red List. They are predicted to be at very high risk of infection by SARS-CoV-2, according to the study.

About 40% of the species potentially at risk are classified as "threatened" by the IUCN.

Other animals noted as high risk include white-tailed deer, bottlenose dolphins, giant anteaters, and Chinese hamsters.

Domestic animals, including dogs and cats, were found in the study to have a medium risk. There have already been documented cases of dogs and cats, as well as lions and tigers, and mink.

In many of these cases, researchers believed that the animals contracted coronavirus from humans. Because of the possibility of zoonotic transmission (when a disease is spread from animals to humans or vice versa), researchers and scientists at zoos are strengthening protocols to protect both animals and the humans who care for them.

“Zoonotic diseases and how to prevent human to animal transmission is not a new challenge to zoos and animal care professionals,” said co-author Klaus-Peter Koepfli, senior research scientist at Smithsonian-Mason School of Conservation and former conservation biologist with the Smithsonian Conservation Biology Institute’s Center for Species Survival and Center for Conservation Genomics. “This new information allows us to focus our efforts and plan accordingly to keep animals and humans safe.”

The study authors caution that more research is necessary to confirm the actual risks and warn against over-interpreting the results based only on the computational results. You can see the entire list of animals here. (Click on the "data" tab.)