The life cycle of the trematode N. salmincola requires presence of the snail Juga in the freshwater environment to complete its life cycle. The N. Salmincola worm carries a bacteria in salmon that is the actual pathogen that kills dogs. Systems in Alaska lack the snail, so there is no N. salmincola present, and they can feed salmon to their dogs without getting them sick.

N. salmincola has also been linked to poor marine survival in Puget Sound salmonids.