Wild rats are host to many nematodes that rarely infest laboratory rats, but there is ample evidence of wild rats serving as sources of laboratory rat infestations, generally through contamination of feed and bedding and occa­sionally through arthropod intermediate hosts, such as cockroaches.

One survey of wild rats in urban Baltimore revealed a remarkably high prevalence of Nippostrongylus braziliensis, Rodenolepis nana, Hymenolepis diminuta, Heterakis spumosa, and Trichuris muris. In addition, a survey of wild rats in New Haven, CT by one of the authors (SWB) also found a high prevalence of Gonglyo- nema neoplasticum, Calodium (Capillaria) hepaticum, and T. crassicauda.

More on the topic Wild rats are host to many nematodes that rarely infest laboratory rats, but there is ample evidence of wild rats serving as sources of laboratory rat infestations, generally through contamination of feed and bedding and occa­sionally through arthropod intermediate hosts, such as cockroaches.: