RT Journal Article SR Electronic T1 Myocarditis in naturally infected pets with the British variant of COVID-19 JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.03.18.435945 DO 10.1101/2021.03.18.435945 A1 Ferasin, Luca A1 Fritz, Matthieu A1 Ferasin, Heidi A1 Becquart, Pierre A1 Legros, Vincent A1 Leroy, Eric M. YR 2021 UL http://biorxiv.org/content/early/2021/03/18/2021.03.18.435945.abstract AB Domestic pets can contract SARS-CoV-2 infection but, based on the limited information available to date, it is unknown whether the new British B.1.1.7 variant can more easily infect certain animal species or increase the possibility of human-to-animal transmission. In this study, we report the first cases of infection of domestic cats and dogs by the British B.1.1.7 variant of SARS-CoV-2 diagnosed at a specialist veterinary hospital in the South-East of England. Furthermore, we discovered that many owners and handlers of these pets had developed Covid-19 respiratory symptoms 3-6 weeks before their pets became ill and had also tested PCR positive for Covid-19. Interestingly, all these B.1.1.7 infected pets developed atypical clinical manifestations, including severe cardiac abnormalities secondary to myocarditis and a profound impairment of the general health status of the patient but without any primary respiratory signs. Together, our findings demonstrate for the first time the ability for companion animals to be infected by the B.1.1.7 variant of SARS-CoV-2 and raise questions regarding its pathogenicity in these animals. Moreover, given the enhanced infectivity and transmissibility of B.1.1.7 variant for humans, these findings also highlights more than ever the risk that companion animals may potentially play a significant role in SARS-CoV-2 outbreak dynamics than previously appreciated.Competing Interest StatementThe authors have declared no competing interest.