Whipworms are intestinal parasites which are about 1/4 inch (6 mm) long. They live in the cecum and colon of dogs where they cause severe irritation to the lining of those organs. This results in watery, bloody diarrhea, weight loss, and general debilitation. They are one of the most pathogenic worms found in dogs .

How did my dog get whipworms?
Whipworms pass microscopic eggs in the stool. The eggs are very resistant to drying and heat, so they can remain viable in the dog's environment for years. They mature and are able to reinfect the dog in 10-60 days. The eggs are swallowed and return to the lower intestinal tract to complete the life cycle.

How is whipworm infection diagnosed?
Whipworms are diagnosed by finding eggs with a microscopic examination of the stool. However, multiple samples are often required because these parasites pass small numbers of eggs on an irregular basis. Any dog with chronic diarrhea can be reasonably suspected to have whipworms, regardless of several negative stool examinations. It is an accepted practice to treat for whipworms based on assumption of infection. Response to treatment is an indication that whipworms were present but could not be detected on fecal examination.

How are whipworms treated?
Where are several drugs that are very effective against whipworms. Two treatments are needed at a 3-4 week interval, but because reinfection is such a problem, it is advisable to treat again every 3-4 months or to put the dog on a heartworm prevention product that contains an ingredient that prevents infection with whipworms. Whipworms are not nearly as common now because of widespread use of the types of heartworm prevention products.

Can I get whipworms from my dog?
No. Whipworms are not infectious to people; they are parasites of the dog.