Dissertations and Theses

Date of Degree


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)


Environmental, Occupational, and Geospatial Health Sciences


Jean Grassman

Committee Members

Chloe Teasdale

Glen Johnson

Sarah Hamer

Subject Categories

COVID-19 | Other Animal Sciences | Other Immunology and Infectious Disease | Public Health | Veterinary Infectious Diseases


SARS-CoV-2, COVID-19, Zoonoses, Companion Animals, Dogs, Cats



Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the virus that causes coronavirus disease-2019 (COVID-19) in humans, can also infect domestic dogs (Canis lupus familiaris) and cats (Felis catus). Susceptibility and viral transmissibility in these species are concerns for public health due to the spillover risk to humans or other animals. This dissertation uses a One Health framework to explore key issues on this topic. We aim to identify gaps in understanding of SARS-CoV-2 in companion animals and investigate novel surveillance methods through human, animal, and environmental health perspectives.


Paper 1 provides an in-depth exploration of the topic by synthesizing information on the factors that may impact viral susceptibility, transmission dynamics, and sustained viral transmission across species. Paper 2 implements a laboratory study to identify the sensitivity and specificity of human COVID-19 rapid antibody and antigen tests (RATs) with dog and cat biological samples. Paper 3 discusses a field surveillance study of companion dogs at dog parks in which human COVID-19 RATs were employed to detect SARS-CoV-2 antigen in canine feces and confirmatory real-time polymerase chain reaction (RT-PCR) testing was performed, in conjunction with owner questionnaire responses.


The literature reviewed in Paper 1 suggests similar pathologies and risk factors for SARS-CoV-2 across species, evidence of cross-species transmission events and viral mutations, and concerns about sustained viral transmission among unowned animal populations. The Paper 2 results show low-to-moderate sensitivity and specificity for human COVID-19 RATs and rapid antibody tests when used with animal samples. In Paper 3, there were 20% positive RAT results with canine feces but the RT-PCR results were negative.


We suspect that cases of SARS-CoV-2 infection in dogs and cats, and cross-species transmission with humans, may be underestimated. Further studies of lateral flow assays with animal samples could provide accessible methods for widespread surveillance by veterinarians, public health professionals, and pet owners. A One Health approach is recommended when considering the investigation of zoonotic pathogens in companion animals because of the risk posed to both human and animal health.

Available for download on Friday, May 16, 2025