When coronavirus started making headlines in December 2019, experts from the U.S. Centers for Disease Control and Prevention reassured pet owners that coronavirus, the virus that causes COVID-19, posed little threat to companion animals. 

“Further studies are needed to better understand if and how different animals, including pets, can be affected by this virus,” explains Dr. Casey Barton Behravesh, director of CDC’s One Health Office in the National Center for Emerging and Zoonotic Infectious Diseases. “Please do not panic. There’s no reason to be afraid of pets.”

Even though the risks are low, cats appear to be more susceptible to COVID-19 than dogs. Here’s what we know so far. 

Are Cats at Risk for COVID-19? 

To date, cats in countries ranging from Belgium to China have tested positive for COVID-19. Additionally, two cats in New York tested positive for the virus in April. The cats, from separate homes in different parts of the state, were the first pets in the U.S. to test positive for the virus. Both had mild respiratory symptoms and are expected to recover.

One cat lived with an owner who had a confirmed case of COVID-19. It was the second case that Barton Behravesh found interesting.

“There were no individuals in the household confirmed to be ill with COVID-19, so this virus might have been transmitted to the cat by a mildly ill or asymptomatic household member or through contact with an infected person,” she explains. “The cat sometimes went outside, so it could have picked it up from a person outside, too.”

Although they are not domestic cats, four tigers and three African lions at the Bronx Zoo also tested positive for COVID-19.

Dr. Jeanette O’Quin, assistant professor at The Ohio State University, is not surprised that the respiratory disease was diagnosed in cats in an area with a high number of COVID-19 cases. 

“We already knew that cats were susceptible and we expected that [cats would be exposed], especially considering how many human cases there were in New York,” she says. “When you think about the numbers of people who are infected compared to the number of animals that are infected, it’s a very rare occurrence.”

New research published in the journal Science tested the susceptibility of domestic animals, including cats, dogs and ferrets, to coronavirus and found that cats were the most susceptible to airborne infections. In contrast, dogs showed low susceptibility to the virus. 

Not only did the inoculated cats get sick with mild to moderate illness, there was evidence that the infected cats were able to transmit COVID-19 to other cats—though it didn’t happen in all cases. One of the infected cats in New York had a feline “sibling” that tested negative for the virus and just one in three cats housed next to coronavirus-infected cats in the laboratory study contracted the virus.

“In the experimental infection…they inoculated cats in very, very, very high doses—much higher than they would ever be exposed to in a natural exposure—and housed them with cats that they didn’t expose,” O’Quin says. “This experiment shows that it’s possible, but is it probable? We are just not seeing very many infections in pets.”

Why Are Cats More Susceptible to COVID-19?

The reasons cats are more apt to contract the disease than dogs come down to basic biology: Cats have a cell receptor in their upper airway that makes it easier for the virus to cause illness, according to Barton Behravesh. 

O’Quin suggests thinking of the virus and its carriers like a lock and key.

“If the virus enters a duck and…none of the cells have the locks that fit the coronavirus’ key, it doesn’t cause any problems because the virus can’t enter the cells or cause any disruption to the tissues,” she says. 

The virus seems to have a key that fits the lock in cats’ cell receptors, making COVID-19 more likely to cause illness in some cats.

Should You Test Your Cat for COVID-19?

COVID-19 testing for animals is available. Barton Behravesh notes that testing for animals is done in veterinary laboratories and the resources used to test cats for the coronavirus are not taking away from those being used for human testing.

If your cat has symptoms of respiratory illness such as coughing, sneezing, nasal discharge, shortness of breath, fever, vomiting, diarrhea, or lack of energy, you should call your veterinarian—but that doesn’t mean your cat will be tested for COVID-19.

“The decision to test animals right now is at the state level,” Barton Behravesh adds. “A state public health veterinarian and a state animal health official would work together with a veterinarian who suspects that this animal needs to be tested for COVID-19 due to its clinical signs and exposure, and make that decision whether or not to test.”

Let your veterinarian know if your cat has been exposed to someone with COVID-19 so they can make the best decisions about testing and treatment.

“The pets that have become sick so far have been mildly ill,” Barton Behravesh says. “Some of them have needed a little bit of treatment, like IV fluids for example, but nothing too extreme. The majority of pets that have been infected with this virus have been able to be cared for at home.”

Protecting Your Cats from COVID-19

The risk of your cat being diagnosed with COVID-19 is very low but there are steps you can take to further reduce the odds. For starters, Barton Behravesh advises keeping cats indoors or letting them out to explore during supervised leash walks. 

“Not letting your cat roam freely outside is important,” she says. 

Keep your cats separated from anyone who is ill; avoid coughing or sneezing on them, and, if you are ill, someone else in the household should care for your felines. If you are caring for cats while a loved one is sick with COVID-19, O’Quin suggests keeping the cats separated from other people and animals for a few days.

The most important thing you can do to protect your cats is continuing to care for them. 

“Pets are such an important and wonderful part of our lives—there are 94 million pet cats alone in our country right now—and they’re offering us support and companionship during these difficult times,” Barton Behravesh says. “It’s so important to look at the bigger picture and know that this is an uncommon thing for cats to be getting sick. Enjoy your pets.”