Does the Introduction of Alien Species Represent a Sanitary Threat for Native Species? The Case of the Eastern CottontailSylvilagus floridanusin Italy

Introduction of alien species is a well-known threat to biodiversity. Where newly introduced, alien species may pose a risk for the local ecological community by competing for resources or by introducing pathogens.Sylvilagus floridanusis an American lagomorph introduced into Europe in the second half of 20th century, for hunting. This study evaluated the structure and epidemiological characteristics of the gastrointestinal parasite community in an introduced population ofS. floridanusin the Province of Alessandria (Piedmont Region-Italy). Three alien parasites were reported out of 271 animals:Obeliscoides cuniculiin the stomach,Trichostrongylus calcaratusin the small intestine, andPassarulus nonnanulatusin the large intestine. All these nematodes are commonly reported inS. floridanusin its natural range, but they represent alien species in Europe. The report of these alien parasites is an example of the unexpected consequences caused by the introduction of non-native vertebrates. The documented introduction of new pathogens may alter the parasite community of the native lagomorphs, with possible long-term effects on local ecological dynamics.