Cats and dogs with myocarditis tested positive for Alpha variant: study

Your pet cat or dog can also become infected with the Alpha variant of the SARS-CoV-2 virus and develop heart issues, according to a new study published in Veterinary Record that examined cases involving severe myocarditis and the variant that swept through the U.K. last winter.

The study, led by scientists in the U.K. and France, documents for the first time how domestic animals can become infected with the Alpha, or B.1.1.7, variant, considered more transmissible and infections compared to the original virus.

Notably, the pets had all been brought in because they had developed an acute onset of heart disease, including severe inflammation of the heart muscle, or myocarditis, researchers said. Two cats and one dog tested positive on a PCR test, while two other cats and another dog had antibodies two to six weeks after developing heart disease.

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Three to six weeks prior to the pets becoming sick, many of their owners experienced respiratory symptoms as well and also tested positive for COVID-19. Infections had surged across the U.K. last winter as the Alpha variant, first detected in southeast England, quickly became the dominant version spreading through the country and many other parts of the world.

“Our study reports the first cases of cats and dogs affected by the COVID-19 alpha variant and highlights, more than ever, the risk that companion animals can become infected with SARS-CoV-2,” said lead author Luca Ferasin with The Ralph Veterinary Referral Centre in the UK in a statement.

“We also reported the atypical clinical manifestations characterized by severe heart abnormalities, which is a well-recognised complication in people affected by COVID-19 but has never described in pets before.”

Viral infections are a common cause of myocarditis in humans, and at least one study showed that patients who were sick with COVID-19 were almost 16 times more likely to develop an inflammation in the heart muscle. Myocarditis is also a very rare side effect of some COVID-19 vaccines.

Ferasin noticed a dramatic jump in pets diagnosed with myocarditis between December 2020 and March 2021 and said the animals came in with difficulty breathing or were fainting because of the heart issues they had developed, but no other typical signs of COVID-19, according to a report by NBC News. The report also noted that one cat had to be euthanized, but all the other animals recovered after treatment.

A Dutch study published in July found that one out of five pets will catch the COVID-19 virus from their owners.

The Veterinary Record study did not determine whether humans infected with Alpha variant are able to infect animals -- or specific animal species -- more easily than others.

“COVID-19 infection in pets remains a relatively rare condition and, based on our observations, it seems that the transmission occurs from humans to pets, rather than vice versa,” Ferasin said.