The ongoing pandemic of COVID-19 is designated by World Health Organization (WHO) as a Public Health Emergency of International Concern. Similarities among ACE2 receptors predict that there are several animals could function as reservoirs for the virus. Recent studies by us and others identified felid animals, including domestic cats, tigers and lions as highly susceptible to SARS-CoV-2 infection. These findings cause great concerns on the potential for human to animal and animal to human transmission, along with the virus mutations that appear as the virus goes back and forth between species. One goal of this study is to design and prepare novel reagents and assays for detection and surveillance in animals. A second goal is to develop a feline animal model. Together, these data will be incorporated into models for understanding the risk of animal infection for veterinarians, other animal care professionals, and the general public. Specific Aims are: 1). To generate and characterize specific reagents for use in COVID-19 research and diagnostics; 2). To develop diagnostic assays for detecting COVID-19 virus infection in animals; 3). To establish a feline model to study SARS-CoV-2 pathogenesis; 4). To apply novel diagnostic assays in the surveillance of pets and zoo animal populations. Outcomes of this study will generate a panel of SARS-CoV- 2-specific antibody reagents, diagnostic standards, and assays for rapid detection of SARS-CoV-2 infection in all species of animals. The diagnostic assays will be applied to COVID-19 surveillance networks, which will identify important animal reservoirs. The novel serological assay can also serve as a DIVA test to differentiate between the vaccinated and infected animals (and humans). The feline pathogenesis studies will improve our understanding of viral pathogenic mechanisms, host immune responses, and provide the source of samples for early detection and test validation.