Whipworms

Introduction:

Trichuris vulpis is the major species of whipworm found in dogs and rarely in domestic North American cats. It has been found in foxes and coyotes as well.  The life span of the canine whipworm ranges from 5 to 16 months. Whipworms are found worldwide and are highly underestimated in the canine population due to many factors.

Life Cycle:

Whipworm eggs are non-embryonated when passed in the feces and are extremely hardy. Eggs will embryonate in 9 to 21 days depending on the temperature and the soil’s moisture content. Infective eggs remain viable for many years given the right conditions. A dog will ingest the infective egg from the environment, the larvae hatches from the egg, and penetrates the small intestine tissue. The larvae continues to develop over the next 2 to 10 days and migrates to the cecum, small or large intestine where it matures into an adult worm. The prepatent period, or time of infection until the time the infection is detected in the animal, of the whipworm T. vulpis is approximately 74 to 90 days.¹

Disease State:

Many whipworm infections are asymptomatic or go unnoticed. Some infections result in bloody colitis or large bowel diarrhea that is streaked with mucus and/or fresh blood.  Severe infections cause bloody diarrhea, weight loss, dehydration, anemia, and even death in severe cases. Chronic bouts of diarrhea can be a common sign of whipworm infections in dogs.

Diagnosis:

Fecal flotation with centrifugation remains the most common way to test for whipworms. However, detection of whipworm eggs on fecal flotation can prove challenging because female whipworms lay as little as 2,000 eggs, intermittently shed the small number of eggs, and the eggs do not float easily because they are dense.  Whipworm eggs are not commonly found in young pups due to their long prepatent period. Infections may become evident as early as 3 months of age. There is a commercial ELISA test available used to detect antigen or protein from adult whipworms to aid the commonly used fecal floatation for diagnosis.²

Treatment:

There are fewer products labeled to effectively eliminate adult whipworm infections in dogs as compared to roundworms and hookworms.  The best ways to control infection are by promptly removing feces from the environment to limit exposure to infective eggs and administering a product labeled to eliminate the adult whipworms that may be present in the intestine. At this time, there are no reports of whipworms being zoonotic.

The CAPC website and the website Pets and Parasites by CAPC are reliable resources for additional information regarding whipworms and your dog.