Glossary

Whipworm

A parasite of the large intestine whose eggs stay in soil for years and which can cause chronic, mucus-covered diarrhea in dogs.

Also called: Trichuris vulpis, whipworms

Whipworms are thin worms, shaped like a whip with a thread-like front end, that live in the cecum and colon. Dogs swallow the eggs from contaminated soil. The eggs are very hardy and can stay infective in the ground for years, so a heavily used yard or run can reinfect dogs again and again.

Many dogs show no signs. Heavier infections cause weight loss and chronic diarrhea with mucus and fresh blood, and in rare cases a collapse resembling Addison's disease.

Whipworms shed eggs only now and then, so a single stool test can come back negative in an infected dog, and a vet may repeat the fecal test. Many monthly heartworm preventives also control whipworms. Treatment and yard hygiene should be planned with a veterinarian.

Last reviewed November 8, 2026

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Related terms

Roundworm A common intestinal worm that often infects puppies, frequently from the mother, and can pass to people, especially children. Hookworm A small intestinal worm that attaches to the gut wall and feeds on blood, causing anemia in puppies, and can burrow into human skin. Fecal test A laboratory check of a dog's stool for parasite eggs and organisms such as roundworm, hookworm, whipworm and Giardia.