SARS-CoV-2 transmission from infected owner to household dogs and cats is associated with food sharing

Abstract

Objectives: Several cases of reverse transmission of SARS-CoV-2 from human to pets were reported during the first year of the COVID-19 pandemic. Accordingly, the World Organization for Animal Health has recommended to improve SARS-CoV-2 surveillance on household animals to assess the risk of transmission between species. After such recommendation, we studied the potential SARS-CoV-2 infection in household dogs and cats in the city of Guayaquil, the most populated city in Ecuador.

Methods: Oral and nasal swab samples were collected from dogs and cats within 10 days of a positive SARS-CoV-2 test result of their owners. Total ribonucleic acid was extracted and detection of viral gene targets N and ORF1ab was performed by quantitative reverse transcription polymerase chain reaction.

Results: From the 50 cats and dogs tested, 12 were SARS-CoV-2 positive, giving a total positivity rate of 24%. A total of 1 of 8 cats tested positive, whereas 11 of 42 dogs were positive, yielding a positivity rate of 12.5% and 26.2%, respectively. SARS-CoV-2 was confirmed by whole genome sequencing. In addition, we also found a statistically significant association between SARS-CoV-2 pet positivity and food sharing with infected owners.

Conclusion: This study is the second active surveillance of SARS-CoV-2 in household dogs and cats in Latin America. Moreover, it is the first study to address the risk factors associated with potential anthropogenic SARS-CoV-2 transmission to domestic cats and dogs. Given the high presence of free-roaming dogs and cats in rural and urban areas in Latin American countries and the high capacity shown by coronaviruses for interspecies transmission, our findings support the view that SARS-CoV-2 surveillance in pets is necessary to better understand the role that pet-human interaction plays in the COVID-19 spread.

Keywords: Cats; Dogs; Food sharing; Pets; Risk factors; SARS-CoV-2.

Figure 1

Phylogenetic placement of SARS-CoV-2 sequences obtained from RT-qPCR positive dogs in Guayaquil (Ecuador) in comparison with selected genomes of different viral lineages detected in human samples in Ecuador from 2020-2021. The tree was obtained using maximum likelihood method with a GTR substitution model and 1000 bootstrap iterations was conducted using IQ-tree 2.2.0. Dog samples are presented in red with GenBank accession number. Lineage name and GISAID accession number is presented for all other sequences.GTR: general time reversible; RT-qPCR: quantitative reverse transcription polymerase chain reaction.