Whipworm

*Adult Whipworms in the Cecum

Whipworms (Trichuris vulpis, Trichuris campanula) are common in dogs and found throughout the United States. Trichuris serrata is rare in cats. Whipworms get their name from the whip-like shape of the adult worms. The front portion of the worm is very thin (the whip) and the posterior end is thick (whip handle). Whipworms live in the large intestine and cecum (a small 'dead-end' portion of intestine lying at the junction of the small intestine and large intestine).

How are whipworms transmitted and how is whipworm infection diagnosed?

A dog or cat becomes infected by ingesting food or water contaminated with whipworm eggs. The eggs are swallowed, hatch, and in three months, the larvae mature into adults in the cecum and large intestine where they burrow their mouths into the intestinal wall and feed on blood. Adult worms lay eggs that are passed in the feces. The eggs must remain in the soil for about a month to mature and be capable of causing infection.

An infection is diagnosed by finding the eggs in the feces. The eggs must be differentiated from those of the bladder worm (Capillaria plica) and C. aerophilia, a parasite of the respiratory system, but whose eggs may be found in the feces.

What are the signs of whipworm infection?

The signs of infection vary with the number of worms in the intestine. Small numbers of worms cause no signs, but larger numbers can result in inflammation of the intestinal wall. Large amounts of mucous are produced by the inflamed intestine. Sometimes hemorrhage into the intestine occurs, and anemia can result. Animals may have diarrhea and loss of weight.

In very heavy infections, the worms may penetrate through the intestinal wall and the resulting inflammation causes the intestine to adhere (stick) to the body wall. Animals with this condition may frequently lick their right flank area where the adhesion occurs.

Are whipworms a health hazard to people?

There have been reports of people being infected with T. vulpis. Humans are more often infected with T. trichiura, the human whipworm.

How do we prevent and control whipworm infections?

Whipworm eggs are somewhat susceptible to drying, but can remain alive in moist soil for years, and are resistant to freezing. Because of this, animals should be restricted from contaminated areas. There is no effective method for killing whipworm eggs in the soil. The only alternative is to replace the soil with new soil, gravel, and pavement. To prevent exposure, any feces in the yard should be picked up on a daily basis.

Floors in kennels and dog runs should be impervious so they are easier to clean. Kennels, runs, and litter boxes should be cleaned thoroughly, and if possible, be allowed to dry in direct sunlight.

Routine fecal examinations and wormings can help control this widespread parasite.

Because of the zoonotic potential of T. vulpis, care should be taken when cleaning, and people should wear gloves and wash their hands well after these duties.