Experts believe a coronavirus variant swept across the UK and caused dogs to throw up before the 2020 pandemic broke out, reports say.
Researchers believe a spike in reports of dogs falling ill was likely the result of a strain of canine enteric coronavirus (CeCoV) spreading through the UK.
Humans cannot catch this pooch-only variant, which is different to the Covid-19 virus that has so far killed almost three million people around the world.
A new study now shows the results of research from the University of Liverpool and the University of Lancaster into a spate of reports about pets falling seriously ill.
Scientists handed out 1,258 questionnaires to vets and owners and secured 95 clinical samples from 71 animals, Mail Online reports.
Covid tests were carried out on the samples, revealing that the dogs had been infected with canine enteric coronavirus.
The outbreak lasted from December 2019 to March 2020 and peaked on February 2, according to the study.
Most dogs had apparently received their usual vaccines and been dewormed.
Their main symptoms were a loss of appetite and throwing up, although the vast majority recovered on average in less than a week.
Under one per cent of the pooches died after contracting the virus.
The study, which was published in the Emerging Infectious Diseases journal, said: "In conclusion, this multidisciplinary approach enabled a rapid response to a newly described outbreak of canine gastroenteritis and identified a CeCoV as a potential cause.
"Previous CeCoV seasonality suggests further outbreaks may occur."
