Two cats have been identified as having had the virus by researchers at Glasgow University, in findings which scientists hope will improve understanding of the disease.
The risk of virus spread from animals to humans is currently low, and no examples have been found. But once cases decrease in Scotland, the risk of the virus being re-introduced to the population by animals will become increasingly important.
Scientists believe there are likely to be more cats in the UK who have had the disease, as animal testing is limited.
The two cases so far were found by a cat screening programme, and both had respiratory symptoms. Both are believed to have been infected by their owners, who also had symptoms before the cats became ill.
One case was identified through post-mortem lung samples of a four-month-old female Ragdoll kitten.
The kitten’s owner developed Covid-19 symptoms at the end of March 2020, but was not tested.
They brought their kitten to the vet after noticing she had difficulty breathing, but her condition worsened, and she later had to be put down.
The second case, a six-year-old female Siamese, survived.
The cat was taken to the vet with nasal discharge and conjunctivitis, but she later recovered.
A screening programme later found evidence of previous Covid-19 infection.
Lead author of the study, Glasgow University’s Professor Margaret Hosie, said the cases showed why it is important that researchers learn more about the virus.
“Currently, animal-to-human transmission represents a relatively low risk to public health in areas where human-to-human transmission remains high,” she said.
"However, as human cases decrease, the prospect of transmission among animals becomes increasingly important as a potential source of SARS-CoV-2 reintroduction to humans. It is therefore important to improve our understanding of whether exposed animals could play any role in transmission.”
There have been reports of Covid-19 in cats from several countries, as well as in dogs, ferrets and hamsters.
Professor James Wood, head of the Department of Veterinary Medicine at Cambridge University, said: “These are important and interesting findings, adding to the body of evidence that humans can infect their pets, in some cases, as here, leading to clinical disease in the animals.”