Seroprevalence of SARS-CoV-2 in Client-Owned Cats from Portugal

Simple Summary Domestic cats are highly susceptible to SARS-CoV-2. The close contact between humans and cats raises concerns about virus transmission from humans to cats. Thus, this study aims to investigate the presence of antibodies against SARS-CoV-2 in client-owned cats from Portugal, which is an indicator of exposure to the virus. A total of 176 cats, belonging to 94 households, were sampled, and cat owners answered an online questionnaire. Twenty households reported at least one confirmed human COVID-19 case. Forty cats belonged to COVID-19-positive and 136 to COVID-19-negative households. The percentages of cats exhibiting antibodies against SARS-CoV-2 from COVID-19-positive and -negative households were 5.0% and 0.7%, respectively. The two positive cats from COVID-19-positive households had an indoor lifestyle, and their owners maintained a close and frequent contact with them, even after being diagnosed with COVID-19, pointing towards human-to-cat transmission. The positive cat from the COVID-19-negative household had a mixed indoor/outdoor lifestyle and chronic diseases. Owners of the three positive cats did not notice clinical signs or behavior changes. This study highlights the low risk of SARS-CoV-2 transmission from humans to cats, even in a context of close and frequent contact. The close contact between humans and domestic cats raises concerns about the potential risks of SARS-CoV-2 transmission. Thus, this study aims to investigate anti-SARS-CoV-2 seroprevalence in client-owned cats from Portugal and evaluate the infection risk of cats that maintain contact with human COVID-19 cases. A total of 176 cats, belonging to 94 households, were sampled. Cat owners answered an online questionnaire, and cats were screened for antibodies against SARS-CoV-2 using a commercial ELISA. Twenty (21.3%) households reported at least one confirmed human COVID-19 case. Forty cats (22.7%) belonged to a COVID-19-positive and 136 (77.3%) to a COVID-19-negative household. The seroprevalences of cats from COVID-19-positive and -negative households were 5.0% (2/40) and 0.7% (1/136). The two SARS-CoV-2-seropositive cats from COVID-19-positive households had an indoor lifestyle, and their owners stated that they maintained a close and frequent contact with them, even after being diagnosed with COVID-19, pointing towards human-to-cat transmission. The SARS-CoV-2-seropositive cat from the COVID-19-negative household had a mixed indoor/outdoor lifestyle and chronic diseases. Owners of the three SARS-CoV-2-seropositive cats did not notice clinical signs or behavior changes. This study highlights the low risk of SARS-CoV-2 transmission from COVID-19-positive human household members to domestic cats, even in a context of close and frequent human-animal contact.