Helminths are the most common parasites infecting humans in many countries and can cause malnutrition, anemia, growth retardation, and increased susceptibility to other infections. Some 2–3 billion people are thought to have active infections with soil-transmitted helminths.6 Three Trichuris species, namely T. trichiura, T. suis, and T. vulpis are considered zoonotic parasites which are a threat to human health.
The genus Trichuris includes nematodes affecting pets, livestock and other hosts, including human beings. Whipworms can be found in the feces of 23% of healthy dogs. These parasites are called whipworms because of having a really thick ("whip handle") posterior part of the body and a long and slender anterior part. Trichuris vulpis, the canine whipworm, and Trichuris trichiura, the human whipworm, are the most important species in veterinary and human medicine. The helminth Trichuris trichiura is considered the third most common roundworm to infect humans with an estimated 600 million people infected worldwide.
Trichuris vulpis, the dog whipworm, causes an intestinal parasitosis of relevance in current canine veterinary practice. Its occurrence is well-known in pets, kennelled dogs and stray animals, and its eggs contaminate the ground in urban areas all over the world. Adult T. vulpis inhabit the large intestine of domestic and wild canids, such as dogs, coyotes and foxes. They are worms 4.5-7.5 cm long in which the thick, broad tail is about one quarter of the total length of the body. After mating, the females release trichuroid eggs containing a single cell which reach the environment via the faeces and, depending on moisture and temperature conditions, embryonate in the soil over a period of three-eight weeks to form an infectious larva inside the eggs. Eggs may survive and be infectious in the environment for up to 5 years. After the infective eggs have been swallowed by a suitable host, the egg plugs are lysed, the larvae hatch and then penetrate the intestinal glands for up to two weeks where they molt before colonizing the large intestine and reaching adulthood where it feeds on blood in tissue fluids resulting in inflammation and .
Whipworm infection is a common cause of acute, chronic or occasional diarrhea in dogs, sometimes with blood. Because of these signs, whipworm infection is sometimes mistaken for other, more serious forms of bowel inflammatory diseases and cancers as well as other disorders, such as hypoadrenocorticism (Addison disease) due to hyponatremia and hyperkalemia.5 Routin deworming with milbemycin (Interceptor, Sentinel), milbemycin/lufenuron, fenbendazole, febantel, or oxantel is effective at controlling T. vulpis in dogs. Treatment is repeated at 3 weeks and 3 months because whipworms are difficult to eradicate. Regular use of milbemycin for heartworm prevention helps to control whipworm infection. Because whipworm eggs survive so well in the environment, reinfections are frequent. Therefore feces should be collected and disposed of properly. Public dog parks are heavily contaminated with whipworm eggs and it is virtually impossible to eradicate the parasite from the ground.
- Are we paying too much attention to cardio-pulmonary nematodes and neglecting old-fashioned worms like Trichuris vulpis?
- Companion Animal Zoonoses. J. Scott Weese, Martha Fulford
- Handbook of Small Animal Gastroenterology. Todd R. Tams
- Phylogenetic Evidence That Two Distinct Trichuris Genotypes Infect both Humans and Non-Human Primates
- A Dog with Pseudo-Addison Disease Associated with Trichuris vulpis Infection
- Potential Drug Development Candidates for Human Soil-Transmitted Helminthiases