Cattle-derived Salmonella enterica serovar Dublin Infections in Red Foxes (Vulpes vulpes) in Tyrol, Austria

Salmonella enterica serovar Dublin is endemic in the cattle population in some areas of the Austrian province Tyrol, and each year single dairy farms have experienced clinical infections. To ascertain if Tyrolean red foxes (Vulpes vulpes) act as a reservoir for Salmonella spp., we tested hepatic tissue and intestinal content from foxes hunted in the years 2015-16 by using microbiological methods. In addition, we included several fox fecal samples collected on a mountain pasture near chamois carcasses in the investigation. Of 434 foxes tested, nine animals (2.1%) were positive for Salmonella spp. Serotyping revealed five foxes positive with S. Dublin, demonstrating that this serovar exists in the Tyrolean fox population. The fecal samples collected in the area surrounding skeletonized chamois (Rupicapra rupicapra) also tested positive for S. Dublin. These chamois were probably victims of a waterborne outbreak caused by S. Dublin-shedding cattle. Our results indicate that the S. Dublin infections in red foxes were primarily acquired through ingestion of infected cattle material such as abortion tissues, but also by feeding on dead chamois. The findings underline the importance of interspecies transmission in this domestic/wildlife interface.