Study of Canine Distemper Virus Presence in Catalonia's Wild Carnivores through H Gene Amplification and Sequencing

Simple Summary Several red foxes in Spain have recently been identified as testing positive for canine distemper virus (CDV). This study focused on the presence of CDV in wild carnivores in Catalonia (north-eastern Spain) for conservation aims, including the red fox (Vulpes vulpes), badger (Meles meles), American mink (Neogale vison) and Eurasian otter (Lutra lutra). The results confirmed the circulation of CDV in Catalonia, revealing a notable percentage of positive cases in red foxes and European badgers. Phylogenetic and spatial studies emphasise the risk of CDV transmission among carnivores in this region likely due to potential reservoirs, close interactions, and shared environmental spaces. Furthermore, the circulation of CDV in wildlife represents a threat to endangered species such as the European polecat (Mustela putorius).Abstract Canine distemper virus (CDV) is recognised worldwide as an important pathogen in both domestic and wild carnivores. Few data are available on its impact and spread on the wildlife/wildlife-domestic animal-environment interface. This study, aimed at developing a conservation-oriented control strategy, analysed 89 sick or deceased animals from 2019 to 2023 at the Wildlife Rehabilitation Centre in Torreferrussa. RT-PCR and sequencing of the partial H gene were used to detect and analyse CDV in tissues. The total positive percentage was 20.22% (18/89), comprising 13 red foxes (44.8%), 4 European badgers (28.6%), and 1 American mink (4.5%), while 24 Eurasian otters tested negative. Phylogenetic analysis indicated that all of the CDV strains belong to the European lineage. Geographically distant individuals and different species shared the same viral strain, suggesting a strong capacity of CDV for interspecies and long-distance transmission. This calls for further research, particularly focusing on potential impacts of CDV on endangered carnivores.