Small animal review

Hernandez et al (2023) noted that different animal species are possible intermediate hosts that could aid the inter-species transmission of SARS-CoV-2. This study aimed to determine the seroprevalence of SARS-CoV-2 in dogs and cats and evaluate its relationship to coronavirus disease in humans in Villavicencio, Colombia. The prevalence of human COVID-19 cases was compared to the seroprevalence in dogs and cats; 300 dogs and 135 cats were included in the study. The overall seroprevalence of SARS-CoV-2 was 4.6% (3.7% in dogs and 6.7% in cats). There was a weak positive correlation between COVID-19 cases in humans and the seroprevalence of the virus in dogs and cats. The authors concluded that cats were more susceptible to SARS-CoV-2 than dogs. This study provides information about the inter-species dynamics of SARS-CoV-2 transmission.

Bianco et al (2023) also noted that, because several animal species are known to be susceptible to SARS-CoV-2 infection, it is important to examine the occurrence of infection in domestic dogs and cats. The authors of this study performed serological screening to identify SARS-CoV-2 exposure in dogs and cats from three regions of Southern Italy during 2021 and 2022. Serum samples were collected from 89 dogs and 11 cats in 2021, and 577 dogs and 63 cats in 2022. The overall positive prevalence was 2.7%, with dogs more susceptible than cats, in contrast to the above study. However, serum neutralisation tests were only positive in two samples collected from dogs. Serologically distinct SARS-CoV-2 assays showed that there was variant-specific positivity. The authors suggested that the monitoring of SARS-CoV-2 exposure in animals might be affected by the antigenic evolution of the virus, necessitating continual updates of the tests used to detect the virus. Therefore, they recommended that variant-specific serological methods are used for serological screening studies. These types of studies are vital to determine the impact of new variants on animals, how humans might be affected, to identify virus reservoirs and monitor antigenic changes.