Identification of Parelaphostrongylus odocoilei (Nematoda: Protostrongylidae) first-stage larvae in the feces of gray wolves (Canis lupus) by molecular methods.

First-stage nematode larvae with a dorsal-spine (DSL) were detected in five of 1,565 fecal samples from gray wolves (Canis lupus) collected in British Columbia, Canada, between 2005 and 2008. Molecular techniques were used to identify the DSL because it was not possible to determine their species identity using morphologic characters. The DSL were identified as Parelaphostrongylus odocoilei based on the results of single-strand conformation polymorphism (SSCP) analyses and DNA sequencing of the ribosomal DNA first and second internal transcribed spacers. Finding DSL of P. odocoilei in the feces of gray wolves was unexpected because P. odocoilei adults are parasites of cervids and bovids. The most likely explanation for the presence of DSL in wolf feces is that they were ingested along with the viscera of recently consumed prey. This was probably black-tailed deer (Odocoileus hemionus columbianus), which are known in the sampling area to be hosts of P. odocoilei. The present study demonstrates the use of SSCP and DNA sequencing for the identification, to the species level, of parasitic nematode larvae in feces.