Lungworm () Infection in Unweaned Free-Ranging Raccoons () in Washington State, USA.

Larval parasites morphologically identified as were found in orphaned raccoons () admitted to a wildlife rehabilitation center in Washington State, US. Partial 18S rRNA and cytochrome oxidase I gene sequences were most similar to other spp. Although commonly reported in free-ranging raccoons throughout much of the central and eastern US, this finding extends the range of into the Pacific Northwest of North America. Fecal samples taken within 48 h of admission were positive for larvae in 70% (21/30) of individuals and in all five group samples taken from an additional 14 raccoons. Typically, spp. use an intermediate host, but the unweaned status of all the raccoons in this report suggests a potential direct, possibly vertical, route of transmission. Serial fecal analysis of pooled samples collected over several subsequent months demonstrated spontaneous resolution of larval shedding. Adult worms and gross evidence of pneumonia were detected in the lungs of several juvenile raccoons at necropsy, and verminous pneumonia was confirmed histologically in the single case submitted. Clinical signs directly attributable to verminous pneumonia were not seen in most actively shedding raccoons, suggesting that subclinical disease among juveniles may be common.