Gray Wolf

Diseases and parasites
Because wolves travel great distances, they may play an important role in spreading and maintaining diseases in certain areas. Infectious diseases spread by wolves include brucellosis, tularemia, listeriosis and anthrax. Wolves may also suffer from rabies: wolves are a major host for the disease in Russia, Iran, Afghanistan, Iraq and India. Canine distemper seems to only pose a serious problem for wolves in Canada and Alaska. Wolves also carry the Canine coronavirus, with infections being most prevalent in winter months.
However, gray wolf populations are remarkably resilient against disease outbreaks. Usually, a wolf displaying the first symptoms of disease will leave its pack, thus preventing the sickness from spreading to its pack mates. Wolves in the former Soviet Union have been recorded to carry over 50 different parasite species. Ticks carried by wolves include Ixodes ricinus and Dermacentor pictus. Although wolves are host to Sarcoptes scabiei (or mange mite) they rarely develop full blown mange, unlike foxes. Other ectoparasites include biting lice, sucking lice and the fleas Pulex irritans and Ctenocephalides canis. Endoparasites include nematodes such as Toxascaris leonina and T. canis. Wolves are also carriers of Trichinella spiralis, the prevalence of which is significantly related to age.
Other endoparasites include cestodes such as Taenia pisiformis, T. hydatigena, Echinococcus granulosus, Mesocestoidea lineatus, Dioctophyme renale and the adult phase of Multiceps multiceps. Wolves may carry Neospora caninum, which is of particular concern to farmers, as the disease can be spread to livestock; infected animals being three to thirteen times more likely to abort than those not infected. Wolves suffering from tapeworms may deliberately forego eating fresh meat in favour of putrified flesh, in order to rid themselves of the parasites.