The adult whipworm is 2 to 3 inches (50 to 76 mm) long. It is threadlike for the most part, but is thicker at one end, which gives it the appearance of a whip.
The adult worm lives in the last part of the small intestines and the first part of the large intestines, where it fastens to the wall of the gut. The female lays fewer eggs than other worms, and there are long periods during which eggs are not shed. Accordingly, finding eggs in the feces is difficult, even with repeated stool examinations.
Whipworms can cause acute, chronic, or intermittent diarrhea in dogs. Typically, the stool is mucoid and bloody. The diarrhea is often accompanied by urgency and straining (see Colitis). Dogs with a heavy infestation may lose weight, fail to thrive, and develop anemia.
Treatment: A number of preparations are effective against whipworms. They include Panacur, Drontal Plus, Telmintic, and Vercom Paste. However, it is difficult to attain high drug concentrations in the colon, where the whip- worms reside, and this makes them difficult to eradicate. To maximize success, follow up the initial deworming with a second deworming three weeks later and a third deworming in three months.
Prevention: Eggs remain infective in the environment for up to five years. In areas such as public parks and backyards, where the ground has been heavily contaminated with whipworm eggs, frequent reinfection is a common problem. It is important to observe pooper-scooper ordinances and remove stools in the yard every day. Dirt runs should be relocated and paved with concrete or new gravel. Use household bleach in a 1:32 dilution to disinfect concrete and gravel runs. It may be necessary to totally change the gravel in gravel runs.
The drug Interceptor, given to prevent heartworms, also controls and prevents whipworms.