The biological potential of the raccoon dog (Nyctereutes procyonoides, Gray 1834) as an invasive species in Europe—new risks for disease spread?

Invasive wildlife species have the potential to act as additional host and vector species for infectious diseases. The raccoon dog (Nyctereutes procyonides), a carnivore species that has its origin in Asia, was taken as an example to demonstrate biological and ecological prerequisites which enables an invasive species to occupy a new habitat permanently. Studies conducted during the last 20 years identified a total of 35 species of endoparasites, five ectoparasites, six bacterial or protozoan species, and five viruses found in the subspecies Nyctereutes procyonoides ussuriensis in its original and newly occupied habitat or in Nyctereutes procyonoides koreensis in its original habitat, respectively. With reference to raccoon dogs impact as vector species and the relevance for human and animal health, we selected Trichinella spp., Echinococcus multilocularis, Francisella tularensis, rabies virus, and canine distemper virus for detailed description. Results of studies from Finland and Germany furthermore showed that biological characteristics of the raccoon dog make this carnivore an ideal host and vector for a variety of pathogens. This may result in a growing importance of this invasive species concerning the epidemiology of some transmissible diseases in Europe, including the hazard that the existence of autochthonous wildlife, particularly small populations, is endangered. Potential adverse effects on human and animal health in the livestock sector must also be taken into account. Especially with regard to its potential as a reservoir for zoonotic diseases, the raccoon dog should receive more attention in disease prevention and eradication strategies.