Baylisascaris procyonis

Baylisascaris procyonis, referred to often as the raccoon roundworm, is a common parasite of raccoons. As adult worms, B. procyonis can reach lengths of 7 to 28 cm.

Hosts: Although raccoons are the primary carriers of B. procyonis, dogs can sometimes carry it as well. Since dogs frequently eat feces of other animals, they have also been found to harbor the parasite in their bodies as well, and shed the eggs in their feces. B. procyonis eggs are not infective in fresh feces. It takes 2-4 weeks for the eggs to embryonate in the environment, before they become infective.

Transmission: Poultry become infected when they accidentally ingest infective roundworm eggs in soil, water, or on objects that have been contaminated with raccoon or dog feces. When birds ingest these eggs, they hatch into larvae in their intestine, and travel throughout the body, affecting the organs and muscles. Depending on where the larvae migrate, B. procyonis can infect the brain and spinal cord, the eye, and/or other organs.



  • Order: Ascaridida
  • Family: Ascarididae
  • Genus: Baylisascaris


  • raccoons
  • dogs

Associated Diseases