Mystery Parasite

Deer lung with cysts, intermediate stage of a tapeworm.An unidentified parasite was recently found in Humboldt County in a black-tailed deer lung. A hunter-harvested deer was discovered to have a multitude of small fluid-filled cysts scattered throughout the lung tissue. It’s suspected to be the intermediate stage of a tapeworm, known as “cysticercosis”, but this is uncertain since Dr. Pam Swift (Wildlife Investigations Lab ) and Dr. Leslie Woods (California Animal Health and Food Safety Lab, UC Davis) have not seen this pathology before. A sample was submitted to the UC Davis lab and the National Veterinary Services Laboratory in Ames, Iowa, for identification.  Results will take up to 30 days.  Deer can ingest the tapeworm eggs while grazing.  Upon hatching, the tapeworm larvae migrate to various tissues and form cysts.  Here the cysts remain until the deer is consumed by a carnivore. The cysts eventually develop into an adult tapeworm in the carnivore. The hunter was contacted by the Department of Fish and Game biologist for Humboldt County and instructed not to consume the meat.