Diversity and ecology of pulmonary metastrongyloidosis in coyotes (Canis latrans) of Nova Scotia, Canada

Coyotes (Canis latrans) are widely distributed in North America and were first recorded in Nova Scotia, Canada, in 1977. Although coyotes are host to a number of parasitic helminths, the parasite fauna of coyotes from Nova Scotia has not been previously investigated. The objectives of this study were to determine geographical range, prevalence, mean intensity, and abundance of metastrongyloid helminth parasites of the pulmonary system (Crenosoma vulpis, Oslerus osleri) in coyotes from Nova Scotia and to investigate whether prevalence, mean intensity, and abundance were consistent among different age classes of this mammal. In addition, hearts and pulmonary arteries were examined for the presence of Angiostrongylus vasorum (French heartworm) and Dirofilaria immitis (heartworm) to determine whether these heartworms had spread to Nova Scotia. A total of 235 coyotes were collected from trappers in the 2010–2011 season. Heart and lungs were removed from coyotes and examined for parasites by gross examination and lungflush. Canine teeth from lower jaws were removed to assess the age class of each coyote. Crenosoma vulpis and O. osleri were found in 31% and 37% of coyotes, respectively. There was a mean intensity of 8.8 adult C. vulpis and 9.5 nodules of O. osleri in infected coyotes across all age classes, with a tendency toward higher worm burdens in juvenile animals; significant differences were observed only for C. vulpis. There was a mean abundance of 2.7 adult C. vulpis and 3.5 nodules of O. osleri in coyotes sampled across all age classes, with significantly higher numbers of each species of worm in juveniles. Dirofilaria immitis and A. vasorum were not detected. The life history implications of these findings are discussed in relation to the possibility of parasite transmission to domestic dogs