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Cats can infect each other with COVID-19. This conclusion was reached by American researchers after experimentally studying the susceptibility of these animals to the new virus. However, none of the infected cats showed clinical symptoms, so the likelihood of developing a severe form of the disease in these animals is low. Interestingly, dogs do not seem to be able to spread SARS-CoV-2: no viral particles could be detected in their secretions. Experimental results set out in the article for the magazine Proceedings of the National Academy of Science.
In recent months, experts have studied relatively well how the SARS-CoV-2 coronavirus is transmitted from person to person. But not only people can become infected with it, but also animals – for example, pets cats and dogs… The question of how dangerous a new infection is for our pets and whether they are able to re-transmit it to humans worries not only their owners, but also epidemiologists. Nevertheless, there is still no clarity on this issue.
A team of scientists led by Angela M. Bosco-Lauth from the University of Colorado decided to experimentally assess the vulnerability of domestic animals to SARS-CoV-2. To do this, they selected five cats and three dogs, which were healthy before the start of the experiment, and injected liquid with viral particles into their nasal cavity.
Over the next few weeks, the authors monitored the health of three cats and all dogs. They had regular blood samples taken, as well as nasal and pharyngeal swabs. On the 28th day of the experiment, the cats were re-injected with the liquid with the virus, and after two weeks they were euthanized and their tissues were examined.
Two more cats were used to find out if representatives of this species can transmit the infection to each other. 48 hours after infection, they were placed in the same enclosure with two healthy relatives. Five days after the start of the experiment, the first two animals were euthanized for further research, and thirty days later the same fate befell the cats in contact with them.
Although the experimental dogs and cats were infected with SARS-CoV-2, they did not develop any external symptoms of COVID-19. For example, their body temperature did not rise above the normal 39.5 degrees Celsius, and the pathologies characteristic of this disease did not appear on the X-rays of the lungs. Autopsy of euthanized cats revealed only mild lesions of the respiratory system.
The findings are at odds with previous studies that found respiratory and digestive problems in animals infected with COVID-19. According to the authors, the reason for this lies in the different physical state of animals.
A blood test revealed antibodies to SARS-CoV-2 in infected animals of both types, which persisted throughout the experiment. In cats, they appeared on the seventh day, and in dogs, on the fourteenth. Reinfection of three cats resulted in a moderate rise in antibody concentration.
Viral particles were found in nasal and pharyngeal swabs taken from experimental cats. They reached their maximum concentration on the third day after infection, and on the fifth day their production ceased. Contact individuals began to release viral particles twenty-four hours after meeting with infected relatives, and this process reached its peak a week later. At the same time, after re-infection, the release of viral particles did not occur.
An autopsy revealed the presence of the virus in the nasal cavity, trachea and esophagus of cats euthanized on the fifth day after infection, but the infection did not reach the lungs and other internal organs. Interestingly, it was not possible to find traces of viral particles in the secretions of infected dogs. They may not be able to infect their relatives with COVID-19.
The authors believe that although cats can become infected with SARS-CoV-2, the chances of developing a severe form are very slim. In addition, although they spread viral particles, this does not last long, so they are unlikely to have time to infect a person. However, the researchers advise against letting confirmed cats go outside to limit the spread of infection to domestic and wild animals. On the other hand, the response of cats to COVID-19, especially the rapid formation of antibodies and the ability to infect relatives, make them a good model for studying this disease.
During the coronavirus quarantine, their pets became the only company for many people. It seems that they were supposed to help the owners survive self-isolation. However, how showed In a UK study, cats, dogs and other pets did not significantly improve a person’s mental health and loneliness.
Sergey Kolenov
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