Zoonotic hookworms are hookworms that live in animals but can be transmitted to humans. Dogs and cats can become infected with several hookworm species, including Ancylostoma brazilense, A. caninum, A. ceylanicum, and Uncinaria stenocephala. The eggs of these parasites are shed in the feces of infected animals and can end up in the environment, contaminating the ground where the animal defecated. People become infected when the zoonotic hookworm larvae penetrate unprotected skin, especially when walking barefoot or sitting on contaminated soil or sand. This can result in a disease called cutaneous larva migrans (CLM), when the larvae migrate through the skin and cause inflammation.

Image: L: Filariform (L3) hookworm larvae. These L3 are found in the environment and infect the human host by penetration of the skin. Center: Two dogs playing. Worming your pet regularly will prevent zoonotic hookworm infection. R: Extreme magnification of the anterior end of an adult of Ancylostoma caninum, a dog parasite that has been found to produce a rare human infection known as eosinophilic enteritis. Credit: DPDx