Establishment of an ex vivo lung explant culture model for dogs and cats to study SARS-CoV-2 infection

The COVID-19 pandemic has highlighted the importance of developing advanced models to study host-pathogen interactions, particularly regarding how SARS-CoV-2 affects domestic animals. This study aimed to establish ex vivo lung explant culture model derived from recently deceased domestic cats and dogs to investigate SARS-CoV-2 infection. Lung tissues from recently deceased animals were collected, processed, cultured and infected with the Delta and Omicron variants of SARS-CoV-2. The infection was monitored at 6, 12, and 24 hours post-infection (hpi) through quantitative reverse transcription PCR (qRT-PCR). The results revealed viral replication across all time points, with cycle threshold (Ct) values ranging from 17 to 19, indicating high viral load in both variants in both dog and cat. This model maintains tissue integrity and viability, offering a more physiologically relevant platform for studying viral interactions in animal tissues compared to traditional cell lines. The study also demonstrated the potential role of domestic animals as viral reservoirs, contributing to zoonotic transmission risks. This ex vivo explant model provides a valuable tool for exploring host-pathogen interactions, testing antiviral therapies, and investigating cross-species transmission dynamics. Future applications could extend to other respiratory pathogens, contributing to broader zoonotic disease control and pandemic preparedness strategies.