Whipworms (Trichuris vulpis, Trichuris campanula
) are common in dogs and found throughout the United States. Infections with Trichuris serrata
, the whipworm that affects cats, is rare in that species. 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 cat or dog 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, Capillaria felis cati) and C. aerophilia, a parasite of the respiratory system, but whose eggs may be found in the feces.
Special care must be taken in examining stool samples from cats. Rodents and mice have parasites whose eggs look like those of feline whipworms. If a cat would ingest one of these infected prey animals, the eggs may pass undigested through the intestine, be found in the cat feces, and an inaccurate diagnosis of whipworm infection could result.
What are the signs of whipworm infection?
Trichuris infections are rare in cats. If they do occur, the worms are usually present in small numbers, and signs of the infection are rarely present. There have been several cases of more serious infections, in which the cat had small amounts of blood in the stool and was anemic.
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 is a whipworm infection treated?
There are no FDA-approved medications for treating whipworm infections in cats. A cat with a confirmed diagnosis of whipworms showing signs of infection would need to be treated with medications other than the traditional wormers for cats.
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.
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 parasite in catteries or other areas where it may be a problem.