About one in 10 cats living in France suffered a coronavirus infection in the first two years of the pandemic, according to a study by biologists who studied blood samples from more than two thousand animals.  This once again confirmed the high vulnerability of cats to COVID-19, according to an article in the bioRxiv digital library. The SARS-CoV-2 coronavirus can penetrate not only humans but also many other mammals. These include rhesus macaques, mink, ferrets and cats, which are almost as affected by the infection as humans. A team of biologists led by researcher Eric Leroy of the University of Montpellier (France) conducted one of the most extensive studies of the spread of the coronavirus among the most common pets - cats and dogs. To obtain such information, the scientists studied randomly collected blood samples collected by veterinarians in different regions of France between October 2020 and June 2021, during the second and third waves of the pandemic. Scientists extracted antibodies from these samples and monitored whether their molecules were able to bind to different fragments of the SARS-CoV-2 envelope. The biologists' analysis showed that such antibodies were present in about four hundred blood samples from dogs and cats, about 7% of the total (5,600 samples). About 27% of these antibodies actively combined with coronavirus particles and neutralized them, indicating the long-term and serious nature of the infection, which affected the four-legged carriers of these molecules. In this regard, as the scientists noted, cats were significantly more vulnerable to COVID-19 than dogs. Almost 10% of them were infected with the coronavirus, twice as many as for dogs, and cats were 75% more likely to suffer more severe forms of the disease, which led to the emergence of powerful neutralizing antibodies. Interestingly, scientists recorded no sex or age differences in the incidence of coronavirus infection in cats, which is common in humans and other primates. In addition, the researchers recorded differences in the frequency of infection in cats in different areas of France. For example, their proportion was minimal in the Auvergne - Rhône - Alpes (4.3%), while in the Center - Loire Valley coronavirus plagued every fourth pet (26.9%). Subsequent observations, Leroy and his colleagues hope, will help to understand what such discrepancies are related to.