# Molecular Evidence of SARS-CoV-2 Virus in Dogs and Cats from Grenada

## TL;DR

This study found SARS-CoV-2 in pets living with infected humans in Grenada, suggesting possible transmission between humans and animals.

## Contribution

It provides molecular evidence of SARS-CoV-2 infection in dogs and cats in Grenada and links them to human cases.

## Key findings

- 12% of dogs and 23% of cats in SARS-CoV-2-positive households tested positive for the virus.
- No infected pets were found in households without infected humans.
- Phylogenetic analysis showed similarity between Grenadian pet and human SARS-CoV-2 sequences and global database entries.

## Abstract

SARS-CoV-2 is a zoonotic virus that has had a devastating impact on the world, causing high morbidity and variable mortality in human populations. However, the role of domestic animals in the dissemination or maintenance of the virus is poorly understood. This study aimed to detect SARS-CoV-2 infection in dogs and cats living in households with and without SARS-CoV-2-positive owners in Grenada using molecular tools. We found that 12% (17/139) of dogs and 23% (5/22) of cats were infected with SARS-CoV-2. All infected pets were from SARS-CoV-2-positive households, and none of the pets in the SARS-CoV-2-negative households were positive. Sequences from the dog, cat, and human showed similarity to the SARS-CoV-2 E gene genome in the NCBI database. This study provides evidence of infection with SARS-CoV-2 in cats and dogs in Grenada and possible transmission between humans and animals. Positive pets were found in households with confirmed human cases. Continuous monitoring of SARS-CoV-2 in pets remains crucial to understanding the epidemiology of the virus.

SARS-CoV-2 is a highly contagious virus that infects humans, wildlife, domesticated and farmed animals. An increase in SARS-CoV-2 variants and human–animal interactions could have implications for the global maintenance and perpetuation of the virus. This study aimed to detect SARS-CoV-2 infection in dogs and cats living in households with and without SARS-CoV-2-positive owners by real-time reverse transcription polymerase chain reaction (qRT-PCR) in Grenada. This cross-sectional study was conducted from August 2020 to April 2022 from dogs (139) and cats (22) in households (96) in Grenada. Nasopharyngeal and oropharyngeal swabs were taken from the dogs and cats to detect SARS-CoV-2. qRT-PCR tests were performed targeting the E and RdRP genes, respectively. Notably, 12% (17/139) of dogs and 23% (5/22) of cats tested positive for SARS-CoV-2. The positive animals were found in 17 (18%) households, all with at least one positive individual. No positive cases of pets were detected in households without infected humans. A statistically significant association (p < 0.0001) was observed between humans with SARS-CoV2 and their pets. Phylogenetic tree analysis showed evidence of a relationship between the Grenadian SARS-CoV-2 E gene and other SARS-CoV-2 E gene sequences available in the NCBI database. This study confirmed the concurrent SARS-CoV-2 human/companion animal infection from households in Grenada. Humans and pet animals were positive synchronously; however, the direction of transmission from pets to humans or vice versa remains unknown. This study suggests that pets could play a role in the maintenance, transmission, and prolongation of infection of human-adapted pathogens such as SARS-CoV-2.