The transmission of COVID-19 to pets has been the source of much discussion within the scientific community.
While reports have confirmed a small, but growing, list of positive cases among companion animals and exotic cats in the United States, new Texas A&M University research efforts are beginning to shed additional light on the topic.
In further exploring the degree to which pets are infected with SARS-CoV-2, the virus that causes COVID-19, a team led by Texas A&M College of Veterinary Medicine & Biomedical Sciences associate professor of epidemiology Sarah Hamer is seeing evidence that pets living in “high-risk” households with people who have COVID-19 in Brazos County and the surrounding areas may also become infected with this virus.
“We’re one of a few veterinary research groups across the country that are conducting similar investigations to provide an enhanced understanding about SARS-CoV-2 infections in pets — asking questions such as, are pets being exposed? Becoming infected? Can they spread the virus to humans or other animals? Do they get sick?” says Hamer. “It’s really exciting that research teams are beginning to respond to the crisis in this way.”
In their ongoing project, Hamer has partnered with Gabriel Hamer in the Texas A&M College of Agriculture and Life Sciences and Rebecca Fischer, in the Texas A&M School of Public Health to recruit participants for the study, sample pets at each household, and test the samples in their laboratory facilities.
“By actively screening pets who may not be symptomatic and who are living with people who have tested positive for COVID-19, Dr. Hamer’s project provides important new information about the transmission pathways of the virus,” says Interim Dean John August. “This project reflects the dedication and leadership of scientists from three of our colleges at Texas A&M, working together with a One Health approach to improve animal and human health and to address this serious pandemic.”
Since beginning their sampling of cats and dogs whose owners consented to their participation, the team has identified two asymptomatic cats from different households in Brazos County that have tested positive for SARS-CoV-2 while living in a household with a person who was diagnosed with COVID-19. Additional pets have confirmatory testing underway.
“At the time we collected samples from these cats at their houses, the owners did not report any signs of disease in their pets during the course of their own illnesses, but one of the cats later developed several days of sneezing after we tested it,” Hamer says.
The study was not designed to test whether pets become infected from owners, or vice versa, Hamer said, but the findings indicate that pets can become infected in high-risk households and should be considered in the way households are managed as part of the public health response.
“The American Veterinary Medical Association and Centers for Disease Control and Prevention COVID-19 One Health Working Group emphasize that people who test positive should isolate from their pets or wear a face mask around their pets, just as they should do with other people,” says Hamer. “We know that is probably really hard if you are quarantined at home and just want to snuggle with your pet, but it is important to do during a person’s illness to protect both human and animal health.”
Hamer also reiterated that the veterinary and scientific consensus still maintains that people shouldn’t be afraid if their animals test positive, and there is no indication that infected pets should be surrendered. At this time, the CDC and the United States Department of Agriculture do not recommend routine testing of animals for SARS-CoV-2.
The team plans to repeat the sampling of any pet with positive test results and to continue to communicate with pet owners. In addition, the team will attempt to isolate infectious virus from the swab samples and conduct antibody testing from serum (blood) samples for all pets in the study to learn about animal infection and exposure.
The team has been sampling pets living in households with a family member who has been diagnosed with COVID-19 since mid-June, with owners opting their pets into the study after being diagnosed with the disease.
“Our goal is to learn more about the different roles that pets may play in the transmission cycle of SARS-CoV-2 and to understand the timing of animal infections in relation to human infections,” says Hamer. “We hope that the information will be used to enhance surveillance programs and, ultimately, help protect both human and animal health.”
Hamer is working closely with the Brazos County Health Department, which is assisting with sharing information about the project to those who test positive for pet-enrollment purposes. So far, the team has sampled several dozen households across the county.
Samples are tested through the team’s own biosafety level two and three research labs on campus. Samples that are initially positive on the two tests performed at the Texas A&M labs are considered “presumptive positive” and are then sent to USDA’s National Veterinary Services Laboratories for confirmation. The team is also working with the Texas Department of State Health Services and the Texas Animal Health Commission in data reporting.
“We have a pretty rigorous testing approach here at A&M. After RNA extraction, the samples have to test positive in two different assays with our lab team before being sent to NVSL,” Hamer says. “All of our field and lab work has been through multiple approval processes with appropriate organizations in looking out for the animal’s and also humans’ best interest.”
The collected data is contributing to a national database and a scientific paper on this work. The team will also be seeking funding to continue the work and also to expand the geographic region of its sampling.
“We hope to continue to be right there to sample pets in these settings so we can contribute more to the emerging science on this topic,” says Hamer. “Our field and lab teams — which include doctoral and postdoctoral researchers, research associates and scientists, and professors from the CVMBS and COALS — have been working really hard, and I appreciate that they’re willing to work long days, especially braving the heat with many layers of personal protective equipment, because it’s one small way we can learn more to help combat the pandemic.”
