Roundworms Life Cycle

There are three species of roundworms that can affect household pets. Toxocara canis will only infect dogs, Toxocara cati will only infect cats, but Toxascaris leonina can affect both cats and dogs.

  1. Transport Host

    • A transport host can be a small rodent, certain species of beetles and even earthworms. Transport hosts carry the eggs to the primary host, often a cat or a dog, or other wild carnivores.

    Eggs

    • For the life cycle to begin, the animal must ingest the eggs of the roundworm. This is usually done by eating food that has come in contact with contaminated feces.

    Larvae

    • Once they've been ingested by the host, the larvae will hatch in the small intestine and live there until they're fully grown.

    Adult Roundworms

    • Once fully grown, adult female roundworms will produce large amounts of eggs. Each day, the infected animal can shed millions of roundworm eggs through its feces.

    Differences in Roundworm Species

    • While the Toxascaris leonina species can only be transferred through infected feces, the Toxocara canis and cati species can be passed from generation to generation through the milk of an infected mother to her young.