Research has shown that Covid is common in pet cats and dogs whose owners have the virus.
Researchers from Utrecht University swabbed 310 pets in 196 households from where coronavirus had been detected.
Results showed six cats and seven dogs with positive PCR results and 54 animals tested positive for virus antibodies.
Experts suggest owners should avoid contact with their pets, just as you would do with other people.
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Dr Els Broens, from Utrecht University, said: "The main concern is not the animals' health but the potential risk that pets could act as a reservoir of the virus and reintroduce it into the human population."
The study showed no evidence of the virus being passed from pet-to-owner but authors said it would be hard to detect while Covid was still spreading easily between humans.
Dr Broens, of the Veterinary Microbiological Diagnosic Centre, said: "We can't say there is a 0% risk of owners catching Covid from their pets. At the moment, the pandemic is still being driven by human-to-human infections, so we just wouldn't detect it."
Researchers from Utrecht University in the Netherlands used a mobile veterinary clinic for households that had tested Covid in the past 200 days.
Cats and dogs were tested for evidence of Covid.
The results, which were presented at the European Congress of Clinical Microbiology and Infectious Diseases, showed 4.2% had evidence of current infection and 17.4% tested positive for antibodies.
Later tests showed all the PCR-positive animals cleared the infection and then got antibodies.
Russian vets have started vaccinating some animals against the disease but Dr Broens doesn't see the scientific evidence for that now.
University of Guelph in Ontario, Canada, had a study which found that cats which sleep in their owner's bed are more at risk of infection.
They tested 48 cats and 54 dogs from 77 households antibodies and asked owners how they interact with their pets.
Results showed that 67% of owned cats and 43% of the owned dogs tested positive, compared with animals from an animal shelter and stray cats in the area.
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A quarter of the pets showed symptoms of loss of appetite to difficulty breathing. Most were mild but three were severe.
The research suggests that because of their biology cats may be more likely to catch Covid.
Professor James Wood said two studies suggest a proportion of cats and dogs may catch the virus from their owners.
"Most reports are that this infection appears to be asymptomatic.
"It also seems that the virus does not normally transmit from dogs and cats to either other animals or their owners."
