This weekend a tiger at the Bronx Zoo tested positive for SARS-CoV-2, the virus that causes COVID-19 in humans. But it’s a leap to worry if your household feline can get or transmit the coronavirus, says Karen Terio, chief of the Zoological Pathology Program at the University of Illinois’ College of Veterinary Medicine, which assisted in diagnosing the tiger.
“A tiger is not a domestic cat, they are a completely different species of cats,” she says. “To date we have no evidence of the virus being transmitted from a pet to their owners. It’s much, much more likely that an owner could potentially transmit it to their pet.”
Even then, the risk of a pet contracting the virus is low. Globally, only two dogs and two cats have tested positive for the virus, according to the American Veterinary Medical Association (AVMA).
The first publicly recorded instance of a pet diagnosed with COVID-19 happened in Hong Kong in late February, and Hong Kong’s Agriculture, Fisheries and Conservation Department along with veterinary experts at the World Organization for Animal Health (OIE) concluded it to be a case of human-to-animal transmission. The pet dog belonged to someone who had the virus, and authorities at the Hong Kong Agriculture Department and OIE believe the dog contracted the virus from its owner.
“Over 1 million human cases at this point worldwide and we’ve only seen four domestic animals test positive so far worldwide, so the risk is very minimal [for COVID-19] to get to pets,” says William Sander, assistant professor of preventive medicine and public health, also at the University of Illinois’ College of Veterinary Medicine.
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Can your pet transmit the virus to you?
At the moment, Sander says, it appears there’s little-to-no risk of pets transmitting the virus to their human owners, with no specific evidence suggesting this type of transmission has ever happened. “That’s why in the U.S. we’re really not pushing hard to test pets at all,” he says. In the U.S., there hasn’t been a single case of a pet diagnosed with the virus, at least according to the country’s Centers for Disease Control and Prevention (CDC).
“There is no reason to think that animals, including pets, in the United States might be a source of infection with the coronavirus that causes COVID-19,” a spokesperson for the AVMA wrote in an emailed statement to TIME. “COVID-19 appears to be primarily transmitted by contact with an infected person’s bodily secretions, such as saliva or mucus droplets in a cough or sneeze.”
Terio, however, emphasizes that there is still much that is unknown. If your pet, for example, did contract the virus, it is not clear whether your animal would show signs of infection the way a human would. The tiger at the Bronx Zoo did show signs of respiratory distress, Terio says, “but there’s a lot that we don’t know about how different animals are going to respond to a viral infection.”
We don’t know if an animal could be an asymptomatic carrier, or if they’d experience a mild or severe form of the disease, Terio adds. “This is the tip of, you know, just trying to figure out what’s going on,” she says. “Unfortunately there are way more questions than answers at this time, and that’s tough…I think this whole thing is unsettling for everybody, and it’s hard when we don’t have good answers for people.”
Out of caution, the CDC and AVMA recommend that sick humans stay away from their animal companions. “Just like you’re keeping your distance from other people, try to have somebody else in your house take care of your pet, just to be overly cautious,” Sander says. If you are sick or showing symptoms and you have to take care of your pet, the CDC recommends avoiding snuggles or touching your pet, and washing your hands thoroughly before and after feeding.
Sander and Terio note that scientists still don’t fully understand how viruses like the one that causes COVID-19 might or might not move between humans and domestic animals.
Several preliminary studies, which have not been peer reviewed yet, have been shared on public access websites in the last week, Sander says, suggesting that some groups of domestic animals can be infected with SARS-CoV-2 in laboratory settings. Similarly, during the 2003 outbreak of SARS-CoV, also caused by a coronavirus in the same family as SARS-CoV-2, researchers determined that cats and ferrets could be infected with the virus—but that was in a lab setting. Those studies determined that there was little cause for concern that transmission—either to humans or to other animals—could happen in a natural environment, Sander says.
To understand SARS-CoV-2, “we base some of our educated guesses on the previous SARS-CoV that came out in 2003,” Sander says. As of now, researchers believe SARS-CoV-2, like the previous SARS, is not likely to transmit from pets to humans.
The AVMA also cautions against over-interpreting the results described in more recent studies, “some of which may report on data from a very small number of animals or provide only preliminary results.”
Can the virus live on fur?
Though studies have shown that the virus can live on a variety of surfaces for several hours or days, both Sander and the AVMA say it is unlikely the virus can live on an animal’s fur, though Terio notes that there isn’t enough research to say that with 100% certainty.
According to a study published in the New England Journal of Medicine, SARS-CoV-2 can live on plastics for 72 hours, on stainless steel for 48 hours, on cardboard for 24 hours and on copper for 4 hours.
“Obviously, pet fur was not one of the [surfaces] they tested,” Terio says. “There are a number of variables involved, but you have the presume that [the virus] could potentially survive for a period of time—of potentially a day or so on the surface. Again, we don’t know the answer.”
In its emailed statement, the AVMA spokesperson writes that while the virus can be transmitted by touching a contaminated surface or object and then touching your nose, mouth or eyes, “this appears to be a secondary route. In addition, smooth, non-porous surfaces such as countertops and doorknobs transmit viruses better than porous materials; because your pet’s hair is porous and also fibrous, it is very unlikely that you would contract COVID-19 by petting or playing with your pet. However, it’s always a good idea to practice good hygiene around animals, including washing your hands before and after interacting with them.”
The bottom line
Though there remain a lot of unknowns, the experts TIME spoke with agree that it is unlikely that a pet can be infected with the virus or that a pet can transmit the virus to humans. But if you are sick, take extra precautions around your animals, because there is a small chance they could catch the virus from you.
“In this time of social isolation, pets are actually a great comfort for the mental health side of things too,” Sander says. “If you aren’t showing any clinical signs of anything, take advantage of having that mental support.”