Parasites in Dogs That Can Be Transferred to Humans

Zoonotic parasites are parasites that can be transferred from animals, such as dogs, to humans. According to the U.S. Library of Nation Medicine, there has been a link between human diseases and parasites spread by dogs for as long as dogs have been domesticated. While many parasite infections are preventable, dog-to-human transmission is always a concern when dogs and humans coexist.

  1. Ascarids

    • Ascarids, or Toxocara canis, are transferred from a mother dog to her puppies through her milk. These parasites grow up to 15 inches long and live in the small intestines, according to the University of Kentucky. Transmission from dogs to humans generally occurs through inadvertent ingestion of the parasite's eggs. Ascarids damage the tissue in organs, such as the liver, lungs, eyes and brain, during migration. A condition commonly found in children infected with ascarids is cutaneous larva migrans syndrome, a painful and unsightly skin condition caused by the parasite.

    Hookworms

    • The most common intestinal parasite in dogs is hookworms, also known as Ancylostoma and Uncinaria. They attach to the wall of the intestines and feed off of the host, causing severe anemia and diarrhea. Transfer to humans occurs through direct skin penetration or ingestion. Additionally, after the hookworms have migrated to the intestines, a condition known as eosinophilic enteritis sometimes occurs in the host.

    Tapeworms

    • The tapeworm, or Dipylidium caninum, is transmitted to dogs via fleas. A dog generally becomes infected when it swallows an infected while grooming itself; humans generally become infected in the same way. While tapeworm infection is more common in children, adults may be affected by the intestinal parasite as well. According to the Center for Disease Control and Prevention, serious risks to humans are rare.