COVID-19 is a term we are all too familiar with. Pet parents are a buzz with the news that their dogs are most likely safe from the novel coronavirus, but is the same true for cats? Recently, a tiger at the Bronx zoo in New York tested positive for COVID-19 and likely contracted it from a zoo keeper that had tested positive. Does this mean that pet owners should also be concerned about their domestic cats?
Cats are already vaccinated for a known feline-specific strain of the disease called Feline Infectious Peritonitis. Unfortunately the vaccine is not effective against the current SARS-CoV-2. Researchers have determined that cats, in addition to hamsters and ferrets, are susceptible to contracting COVID-19 from humans, as well as transmitting it to other cats.
The virus is usually milder in felines than it is in humans but it is hypothesized that they contract it in a similar way. The cellular enzyme to which the coronavirus attaches in order to enter and infect the cell, is very similar between cats and humans. The Angiotensin-Converting Enzyme 2 or ACE-2 is an enzyme usually associated with kidney and vascular function can be found on multiple cells throughout the body, including epithelial cells, lung, kidney and gastrointestinal tract. Feline ACE-2 only contains three amino acids that differ from ACE-2 in humans. This is why it is hypothesized that cats can be infected with COVID-19, while dogs just excrete the virus in their feces.
A team of scientists in China recently published a study on SARS-CoV-2 in cats, where laboratory felines were exposed to a high dose of the virus. The cats subsequently tested positive, confirming that the virus had incubated. Transmission between the cats was also observed. It was uncertain whether the virus could be spread from cats to humans.
Should these results concern cat owners? Experts say that while there is risk, cat owners should not panic just yet. The Chinese study exposed the cats to an abnormally high dose of the virus intranasally, which almost guarantees transmission. While cats are usually in close contact with humans, they would never be exposed to the virus in as high concentration as they were in the study. Furthermore, it is worthy to note that none of the cats in the study displayed symptoms of illness.
If there is a chance that cats could get coronavirus, does this mean that they should be tested? Dr. Karen Terio, chief of the Zoological Pathology Program at the University of Illinois' College of Veterinary Medicine has this to say. "This isn't like we're able to test everybody's domestic cats,” she says, “The testing is very specific, and it's very stringent rules as to who and what samples are able to be tested." Ultimately, the tiger from the Bronx zoo was a specific and novel case, where testing was necessary.
Experts say that if you’re practicing good personal hygiene and social distancing, the risk to you and your cat is possible but low. More research is still needed to determine the overall risk to cats as well as COVID-19 transmission between felines and humans.