Cats and SARS-CoV-2: A Scoping Review

SIMPLE SUMMARY: Cats are susceptible to SARS-CoV-2. Considering the close contact that exists between humans and cats, this is worrisome; virus transmission between species carries a particular risk of leading to the development of new virus variants. Therefore, the aim of this review was to provide a comprehensive overview of what is known concerning the role of cats in the spread of SARS-CoV-2, to guide further research and inform policymakers. The main outcome of this review was that, while cats are susceptible to the virus, and transmission from humans to cats happens regularly, there is currently no evidence of widespread SARS-CoV-2 circulation among cats. Overall, cats seem to play a small role in the spread of the virus. Nevertheless, this review also revealed substantial gaps in research. For instance, large-scale studies including more cats are needed to solidify evidence gathered from individual studies. Moreover, the role of stray, feral, and shelter cats has attracted little research, as well as the possibility of cat-to-cat virus transmission beyond experimental infection. Tackling these gaps in the research is important to adequately evaluate the danger of cats’ susceptibility to SARS-CoV-2, now and in the future. ABSTRACT: Since the beginning of the COVID-19 pandemic, various animal species were found to be susceptible to SARS-CoV-2 infection. The close contact that exists between humans and cats warrants special attention to the role of this species. Therefore, a scoping review was performed to obtain a comprehensive overview of the existing literature, and to map key concepts, types of research, and possible gaps in the research. A systematic search of the databases PubMed, Google Scholar, and Scopus and the preprint servers medRxiv and bioRxiv was performed. After a two-step screening process, 27 peer-reviewed articles, 8 scientific communication items, and 2 unpublished pre-prints were included. The main themes discussed were susceptibility to SARS-CoV-2, induced immunity, prevalence of infection, manifestation of infection, interspecies transmission between humans and cats, and lastly, intraspecies transmission between cats. The main gaps in the research identified were a lack of large-scale studies, underrepresentation of stray, feral, and shelter cat populations, lack of investigation into cat-to-cat transmissions under non-experimental conditions, and the relation of cats to other animal species regarding SARS-CoV-2. Overall, cats seemingly play a limited role in the spread of SARS-CoV-2. While cats are susceptible to the virus and reverse zoonotic transmission from humans to cats happens regularly, there is currently no evidence of SARS-CoV-2 circulation among cats.