Controlling roundworms in dogs

It’s quite common for dogs around the world to deal with roundworms (Toxascaris leonina, Toxocara canis). But young pups often experience the most severe effects of the resulting disease from a roundworm infection. And worst of all, dogs can become infected again and again.

In dogs, roundworm infection* is associated with:1

  • Failure to gain weight
  • Diarrhea
  • Poor haircoat
  • Pot-bellied appearance

*T. Canis only

Roundworms

Roundworm lifecycle in dogs (Toxocara leonina)

Roundworm Lifecycle

Approximately 8-10 weeks after infection, adult roundworms release eggs in the dog’s small intestine.

Eggs are passed in the feces.

Eggs develop in the environment and become infective approximately1 week after being passed in feces.

Infective eggs may be ingested by your pet, directly from the environment.

Secondary hosts, such as a field mouse, comes in contact with egg and becomes a carrier.

Infected vertebrate paratenic host is consumed and larvae are released in the dog’s small intestine, where they become adult worms.

Larvae are released from infective eggs and mature in the dog’s intestinal tract.

Roundworm lifecycle in dogs (Toxocara canis)

Roundworm Lifecycle

Approximately 2-4 weeks after infection, adult roundworms release eggs in the dog’s small intestine.

Eggs are passed in the feces.

Eggs develop in the environment and become infective 2-4 weeks after being passed in feces.

Infective eggs may be ingested by your pet, directly from the environment.

Paratenic hosts, such as earthworms and field mice, ingest infective eggs and become carriers of larvae that arrest in somatic tissues.

Humans may accidentally consume infective roundworm eggs, which can lead to the development of a zoonotic disease affecting the eye, brain and/or other organs.

Infected vertebrate paratenic host is consumed and larvae are released in the dog’s small intestine, where they become adult worms.

Puppies may become infected by larvae through the placenta during pregnancy or the milk during nursing.

Learn about controlling roundworms