Do cats get the novel coronavirus?

Original Japanese by Dr Yuko Nishiyama, DVM 

I have received a variety of questions from cat owners.  

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I have heard that a report about cats getting the coronavirus more readily than dogs was published in Science Magazine. Why is it, then, that the Ministry of Health continues to say people will not be infected by their cats? I am so afraid, I can’t sleep.

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To writer A.

I am a veterinary clinician, not a scientist or research specialist. My job is to examine one animal at a time and cure what ails it. I also disseminate important information from academic researchers regarding global research and its indications for treatment, vaccinations, etcetra.

I believe that my colleagues in academia are more knowledgeable about your question. This is a little outside my field of expertise, but I would like to present my understanding of the research and the publication system itself. Anyone reading this who feels it is inaccurate may feel free to say so. 

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There are many different categories in scientific publications that researchers may avail themselves of. A “Preliminary Report” is one which has not been evaluated by professionals in its field, but shows the hypothesis and raw data findings of its writer. A process known as “Peer Review” involves an appropriately selected panel of experts reviewing the preliminary report according to the standards of the publication and level of expertise of its readers. This research may be conducted by those developing vaccines or working towards academic credentials.

Generally speaking, research begins with preliminary reports. The article Reader A refers to, concerning novel coronavirus infections in cats, is preliminary research. There is no reference to the credibility of the research, whether or not its content is correct or how the findings were extrapolated, nor is it a comprehensive finding.

I am not saying that the thesis is unreliable or of inferior quality.

I can say that publications containing preliminary research, which has not undergone the peer review process, may lead to wonderful discoveries by offering opportunities for publication.

However, I must point out that the author(s) of such research, their data analysis and the accuracy of their experimentation methods must never be taken as gospel without thorough scientific investigation. One must always consider whether research is preliminary or has undergone the appropriate peer review process.

Veterinary associations and specialist committees are not ignoring the reports of novel coronavirus infections in cats. They are reviewing the preliminary research while considering many other theories. Eventually, peer reviews will present the informed, consistent views of researchers. That information will be passed on to practitioners like me and practical guidelines will be put in place.

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Currently, two reports from China (“Susceptibility of ferrets, cats, dogs and other domestic animals to SARS-coronavirus 2” and “SARS-CoV-2 neutralizing serum antibodies in cats: a serological investigation”), both of which are preliminary reports, are circulating via vioRxiv, a site which publishes research yet to undergo the peer review process. At risk of repeating myself, I would like to state that I am not questioning the site’s standards or veracity. Anyone may express an opinion there, almost as we do on SNS. It is a venue for new ideas and breakthroughs. With global interest in the coronavirus, posting information there regarding experiments may be meaningful and has therefore received attention.

The research on cats’ susceptibility to the virus is preliminary. As a world first, it was published by Science as a “report”. It is not, however, not a piece of research which has passed stringent critical assessment by scientists with appropriate knowledge.

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I have read both the above-mentioned reports. I am not an academic; this is my personal opinion of the findings. The report on susceptibility looked at only six cats and three ferrets. This is an extremely small number. I believe there is a need for further research: innumerable viruses were introduced artificially; surely this needs to be compared with natural infection.

The research on neutralizing antibodies in cats showed 15 of 102 cats with positive ELISA results. The research claims that this is a 14.7% infection rate, but there is not a negative control report and no statement telling us whether the other 87 cats were tested negative or not. The cats used were not pets, but cats from shelters and hospitals whose environment may influence tendencies. It would not be appropriate to apply these statistics unilaterally. The inconsistencies of the two types of antibody testing yield inconclusive results. 

Reader A, I must say to you that we really do not not know what to think yet, but of more than one million human coronavirus patients, at least ten percent probably have cats. One hundred

thousand cats have been in close contact with coronavirus patients, but there are no reports of these cats being infected. It seems unlikely to me that many cats will die from being infected with the coronavirus. It is may eventually be shown that cats can carry the virus without showing symptoms and also infect humans, but that is not what current research shows. We will just have to wait for solid research.

American veterinary associations recommend handling the pets of infected humans wearing protective gowns and gloves. Vets are instructed to keep these animals away from others. This is because we must consider the possibility of infection from animals to humans. 

What is most important is to keep yourself safe from the coronavirus. Keep your cat indoors and do not let it come into contact with infected, or possibly infected, humans. If you follow these guidelines, Reader A, your cat will not get COVID-19.

Everyone reading this, please, please stay safe.

April 11 2020