As we continue practicing social distancing and self-isolation in response to the novel coronavirus pandemic, many of us are at home and spending a lot more time with our pets. They can be a tremendous comfort in a time like this; I have yet to find an antidote as soothing as my dog’s peaceful obliviousness to world events.
Amidst all this, it’s natural for pet owners to wonder if they have anything to worry about. Thankfully, the short answer is no. At this time, there is no evidence that dogs, cats, or other household pets spread the virus that causes COVID-19 to people. The long answer is more confusing.
Dogs can already be afflicted with their own varieties of coronavirus, most of which cause a brief bout of diarrhea. But if your dog has ever been diagnosed with “kennel cough,” there’s a chance it was infected with one of the respiratory strains instead. Regardless, the symptoms are usually mild and temporary.
Cats, especially those from shelter environments, are widely infected with their own coronavirus. Much like the canine version, some diarrhea is the most common symptom. But the usually mild nature of the feline coronavirus masks a frightening side. For reasons that aren’t completely understood, it can sometimes transform into a variant that causes a fatal disease called feline infectious peritonitis. These cases are relatively uncommon compared to the large numbers of cats carrying the virus, but they’re tragic all the same.
While pets have their own coronaviruses, it is unclear whether they can be infected with the specific virus that causes COVID-19 in humans. A very small number of dogs and cats (now including a tiger at the Bronx Zoo) have tested positive for the virus, and there is some preliminary evidence that cats can transmit it to one another. But it’s still early days, and the implications remain unclear. Even if they can be infected, it is unknown whether they can readily pass it to people. Despite the global scale of the pandemic, there have so far been no known instances of people catching this virus from household pets, and that is very encouraging.
At this point, you may find yourself with questions. If COVID-19 hopped over from bats, as is currently suspected, could the feline and canine coronaviruses do the same? Or could our pets become vulnerable to this pandemic? The answer is that there isn’t much to worry about in the short term, but that nothing is set in stone. Viruses change over time, and a virus that is well-adapted to one species could eventually happen upon the right mutations in the right genes to allow it to finally make the leap to another. These events are rare and represent legitimate evolutionary milestones. But as we are all currently learning, rare things happen.
This is important from an epidemiological perspective, but there is no practical day-to-day response for pet owners to take. Living in constant fear of specific illnesses becoming zoonotic–transmissible between species–isn’t productive. It is more important to prevent and control zoonotic diseases that already exist. Keeping pets routinely dewormed and properly vaccinated against infections like rabies and leptospirosis will keep you and your family safer than worrying about the staggeringly unlikely odds of becoming the next patient zero.
While animals remain an unlikely route of transmission for COVID-19, it remains wise to regard pets with the same social-distancing rules we are currently practicing with each other. Dogs shouldn’t be greeting each other during walks as they normally might. The risk is low, but at the very least it draws their respective people too close together. And cats should be kept indoors to be certain they haven’t encountered any people, or less likely cats, that may have been infected.
It is understandable that people crave more certain answers in a time of uncertainty, but it is the nature of science–especially emerging science–to avoid absolutes. There’s always “no current evidence to suggest” something, and “no known reason” to worry. This can sound like hedging, but it is born of a rational humility. The implicit acknowledgment of its own limits is why science is ultimately trustworthy.
And right now, science needs some time to figure out this mess. In the meantime, at least it seems safe to cuddle up with your own pets. They’re happy to have you home.
Dr. Mike Fietz is a small animal veterinarian at Georgetown Veterinary Hospital. He received his veterinary degree from Cornell University in 2003 and has lived in Charlottesville since.