People with COVID-19 frequently infect their pets and cats are particularly at risk

By James DuckerJul 1 2021Reviewed by Emily Henderson, B.Sc.

Previous studies have shown that cats and dogs can catch coronavirus disease 2019 (COVID-19) from their owners, but new research attempting to understand how and why this occurs shows sleeping with the owner puts pets at risk.

Cat sleeping on owner's bed. Image Credit: Ellyy/Shutterstock.com

Exploring the origin and outcomes of COVID-19 infection in household pets

Recent clinical evidence has shown that people with COVID-19 frequently pass it on to their pets. During the onset of the pandemic, concerns were raised on the possibility of COVID-19 transmission between people and their pets. Although this mode of transmission was deemed of limited severity, research has yet to determine the mechanism and outcomes of disease transmission when it occurs.

New research being presented at the European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), suggests that infection rates can vary between pets, and that specific activities may increase the risk of infection. Specifically, the event that poses the highest infection risk appears to be when cats sleep on their owner's bed.

The research conducted by Dorothee Bienzle, a professor of veterinary pathology at the University of Guelph, Ontario, Canada, and colleagues, studied the cats and dogs of people who had had COVID-19.

Antibodies to COVID-19 were tested from 48 cats and 54 dogs from 77 households to determine whether pets had experienced previous infection and owners were then surveyed about how they interacted with their pets. Additionally, 75 dogs and cats living in an animal shelter and 75 stray cats that had been seen at a low-cost veterinary clinic were also tested for antibodies.

Surveys included questions on whether owners petted them and kissed them and allowed them to sit on their lap or sleep in their bed as well as whether owners allowed their pet to kiss them or lick them on the face and how long they spent with their pet each day. Additionally, other questions included if their pet had become ill when the owners had COVID-19 and the range of symptoms the animal experienced.

Cats more at risk of infection than dogs, and susceptibility increases with time spent with infected owner

The results of the antibody test and surveys showed varying results between pets and activities.

Of the pets tested, 67% of household cats and 43% of household dogs tested positive for antibodies, showing they had had COVID-19.

Contrastingly, only 9% of dogs and cats from animal shelters and 3% of stray cats showed antibody responses. This shows that the most likely route of disease transmission is from human to pet, rather than the other way round.

For dogs, 20% showed symptoms during illness including a lack of energy and loss of appetite, with some animals also experiencing coughs and diarrhea. However, all symptoms were mild and animals quickly recovered.

When looking at their associated surveys, the time spent between the owner and their dog as well as the type of contact had no effects on the animal's chance of getting infected.

For cats, however, 27% showed symptoms including runny noses and difficulty breathing. Most cases were mild but 3 of the tested cases were severe.

When looking at their associated surveys, the time spent between the owner and their cat did increase the risk of infection. Specifically, data showed that when cays slept on their owner’s bed, cats were highly likely to be infected.

The authors of the study assume that it is the biology of cats including their viral receptors that make them more susceptible to COVID-19 than dogs. Moreover, cats also tend to sleep closer to the face of owners than dogs, increasing their exposure to any infection.

If someone has COVID-19 there is a surprisingly high chance they will pass it on to their pet. Cats, especially those that sleep on their owner's bed, seem to be particularly vulnerable. So, if you have COVID-19, I'd advise that you keep your distance from your pet - and keep it out of your bedroom.

I'd also recommend that you keep your pet away from other people and pets. While the evidence that pets can pass the virus on to other pets is limited, it can't be excluded. Similarly, although pets have not been shown to pass the virus back to people, the possibility can't be completely ruled out."

Professor Bienzle

Studies exploring the effects of COVID-19 on household pets could consider a wider variety of pets across different geographic areas, which could provide further insight into differences in pet treatment and how it affects infection transmission as shown in this study.