Early findings out from a specialist veterinary hospital in England suggested domestic cats and dogs infected with the highly transmissible U.K. coronavirus variant developed heart issues amid a winter-time variant-fueled surge.
“We don’t want to spread panic unnecessarily, especially because at the moment we have a strong suspicion of transmission from human to pet, but not vice versa – and we don’t know this for sure. But vets ought to be aware of this so that they can start testing if they suspect a potential case of Covid infection,” said Luca Ferasin, corresponding author and a cardiologist at the Ralph Veterinary Referral Centre (RVRC) in Marlow, Buckinghamshire, the Guardian reported.
Study authors behind the findings posted ahead of peer review reported a “sudden surge” of pets presenting with myocarditis, or inflammation of the heart muscle, at the animal hospital between December to February. The pets had no history of heart disease and there was some similarity in the cases, involving lethargy, lack of appetite, shortness of breath and fainting in some instances.
The pet owners started showing respiratory symptoms for coronavirus several weeks before the animals became sick, and many owners had confirmed positive PCR tests, per the study. The B.1.1.7 U.K. variant, believed to be around 50% more transmissible than other strains, accounted for approximately 95% of all new infections in the U.K. as of Feb. 7, and has been detected in over 80 countries, study authors noted.
“Given this coincidence and the intriguing simultaneous evolution of myocarditis in these pets and the B1.1.7 COVID-19 outbreak in [the] U.K., we decided to investigate SARS-CoV-2 infection in these animals,” study authors wrote.
Authors noted that previous reports of domestic pets infected with coronavirus have documented mild respiratory symptoms like a “cough, runny nose, sneezing and conjunctivitis.”
To conduct the study at hand, researchers took swab samples from six cats and one dog, and blood samples from another four pets at least two weeks after they developed signs of heart issues. Swab samples were stored in subfreezing conditions until they were packed in ice and shipped to France for lab testing, which indicated six of 11 animals under study were positive for the virus.
All of the pets made significant improvement after rest and medical treatment, with the exception of one cat prompting euthanasia.
“Although that the B.1.1.7 infection in humans seems to be associated with higher COVID-19 mortality or clinical severity, the association between myocarditis and B.1.1.7 infection in domestic pets has to be acknowledged and addressed,” study authors wrote.
Ferasin, the corresponding author, admitted some bias in the results because the hospital only treats critically ill pets. With this, the true proportion of pets infected with the variant and presenting heart issues is unclear, the outlet reported.
“It is impossible to rule out the possibility that the Sars-CoV-2 shedding was an incidental finding, and it is inevitable that a proposition of any population of animals will test positive for [antibodies to coronavirus] coinciding with the peak for the second wave,” said Margaret Hosie, a professor of comparative virology at the University of Glasgow’s center for virus research, according to the outlet.
Coronavirus infection has been documented in domestic pets and other animals during the course of the pandemic, though cases involving the U.K. variant are just beginning to surface, with one cat in Italy catching headlines last week after it reportedly contracted the U.K. variant from its owners, though said to be in recovery.
If pet owners have concerns, the study author advised contacting a vet, and the other expert, Hosie, cautioned to be aware of human-to-animal virus transmission. If a pet owner is positive for the virus, she suggested keeping away from pets and donning a mask when feeding pets to tamp down transmission.