Baylisascaris /bā′lis·as′kä·ris/ , a genus of ascarid nematodes found in the intestines of mammals, particularly raccoons. B. columnaris infests the central nervous system of dogs. B. procyonis is usually found in raccoons and rodents, but fecal contamination from those animals can cause spread to domestic animals and humans, resulting in larva migrans or eosinophilic encephalitis, which is often fatal.
