Veterinarians warn of a possible link between a new variant of coronavirus and heart problems in cats and dogs following an increase in pets who have myocarditis at a specialist veterinary hospital in Buckinghamshire during the second wave of the pandemic.
‘We do not want to spread panic unnecessarily, especially as we currently strongly suspect that it is transmitted from human to pet, but not the other way around – and we do not know for sure. But veterinarians need to be aware of this so they can start testing if they suspect a possible case of Covid infection, ‘said Luca Ferasin, a cardiologist at the Ralph Veterinary Referral Center (RVRC) in Marlow, Buckinghamshire, who led the research. said. which has not yet been judged by peers.
The highly transmissible B117 variant was first detected in Kent in December and quickly became the dominant circulating variant in the UK, accounting for around 95% of infections. It has been detected in at least 85 other countries worldwide.
Although cats and dogs are known to be infected with earlier variants, their symptoms were predominantly breathing: runny nose, cough, sneezing or conjunctivitis. The cases in Buckinghamshire are among the first documented animal infections with the B117 variant.
Ferasin and his team ask colleagues to be on the lookout for cats or dogs that have symptoms of heart failure, and to have them tested for coronavirus – especially if their owners have recently been infected. The vets hope this will help them better understand how the new variant affects the two animals, and their potential role in transmitting the virus.
Between December and February, Ferasin and his colleagues noticed an increase in the number of dogs and cats admitted to the RVRC with myocarditis (inflammation of the heart muscle). The number of cases was not large – only 18 in total – but it was almost ten times larger than what the animal hospital would normally see at this time of year.
The animals were referred to symptoms indicative of heart failure, including lethargy, lack of appetite, rapid breathing or shortness of breath, as well as severe life-threatening arrhythmia (irregular heartbeat). Two of the cases include fainting episodes. Further tests showed that they had myocarditis.
This increase in cases reflects the curve and timeline of Covid-19 cases of people driven by the B117 variant at the time. In most cases of myocarditis, the owner experienced Covid symptoms or tested positive for three to six weeks before their pet became ill. Many of the pets also tested positive for coronavirus.
Unlike previously documented Sars-CoV-2 infections in cats and dogs, the animals referred to the RVRC had no other respiratory symptoms.
Ferasin wondered if these heart disorders could be linked to the increase in Covid cases in humans, and took blood samples and swabs from the noses, throats and rectum of six cats and one dog with myocarditis between late January and early February. It has been tested on Sars-CoV-2, or antibodies against the virus. They also took blood samples from two cats and two dogs recovering from myocarditis in the intensive care unit. Of the 11 animals, two cats and a dog tested positive for the virus in their rectal samples, and two more cats and a dog had antibodies to Sars-CoV-2 in their blood. It is possible that would have tested more positive if these tests had been performed earlier, Ferasin said.
With the exception of one cat that eventually had to be culled, all the animals recovered well after medical treatment. Covid is also associated with heart damage in humans.
However, it is not yet clear if the virus caused the animals’ symptoms, says Margaret Hosie, a professor of comparative virology at the University of Glasgow’s virus research center. ‘It is impossible to rule out the possibility that the Sars-CoV-2 shedding was an accidental finding, and it is inevitable that a proposal from any population of animals will test positive for [antibodies to coronavirus] coincides with the peak for the second wave, ”she said.
At this stage, it is also impossible to say which part of animals infected with the B117 variant may develop these heart problems. “We’re a little biased because we only see heart patients, and we only see the critical people,” Ferasin said. “My advice is that if people suspect something is wrong with their animal, they should contact their veterinarian.”
Only three other cases of the B117 variant have been reported in pets so far, all in the past few days: a cat and dog from the same household in Texas and a cat in Italy. In both households, the owners also tested positive with B117.
Mick Bailey, professor of comparative immunology at the University of Bristol, said: ‘The ability of earlier tribes to infect cats and dogs has been established, both in the UK and elsewhere. Ferasin’s article shows that B117 can also infect cats and dogs, but we should not be surprised. Since it seems to be more easily transmitted to humans, we should also not be surprised if it is better to infect cats and dogs.
“Although infection of animals with humans is also theoretically possible, the success of closing social interactions between humans strongly suggests that interaction between animal and human is not a major problem.”
Hosie said: ‘The message to pet owners is the same. If you have Covid-19, you should know that it can be transmitted to pets. Avoid contact with your pet and wear a mask if this is not possible. for example, when preparing the pet’s food. ”