Trichurs vulpis, the whipworm of dogs, and the other species of Trichuris infecting domestic and free-ranging mammals, is one of a few parasites of veterinary importance in the Class Enoplea (most are in Orders in the Class Rhabditea). Others within the Order Trichurida are species within the genera Trichinella and Capillaria, which infect a variety of mammals and birds.
All species of Trichuris have a similar structure and life cycle.
Adult T. vulpis are up to approximately 75 mm in length and have a characteristic “whip” shape, slender anteriorly and broader posteriorly.
Eggs of T. vulpis measure approximately 70 to 90 µm by 30 to 40 µm and, because of the polar plug at each end, are commonly described as “lemon” shaped.
Host range and geographic distribution
Life cycle - direct
Adult T. vulpis live in the caecum, with their anterior ends “threaded” into the mucosa. Eggs are passed in the feces and larvate in environment in 10 days. Infection follows ingestion of the larvated eggs which hatch in the intestinal lumen, releasing larvae that undergo a mucosal migration. The pre-patent period is realtively long, approximately three months.
Pathology and clinical signs
Treatment and control
Several products available in Canada are effective against the stages of Trichuris vulpis in the GI lumen of dogs. Trichuris vulpis is not susceptible to some of the more traditional anti-parasitics used for ascarids and hookworms, but most of the newer products are very effective. There are no products approved in Canada for Trichuris infection in cats, which either does not occur or is very rare.
|Mibemycin with Lufenuron
|Milbemycin with Spinosad
|Moxidectin with Imidacloprid
|Pyrantel pamoate with Febantel and Praziquantal
Additional information on the products mentioned is available from the Compendium of Veterinary Products (Twelfth Edition, 2011), or from the manufacturers.
Control of T. vulpis in individual dogs can usually be achieved by appropriate anti-parasitic treatment. In groups of dogs in kennels, however, control may be more difficult, primarily because the eggs of T. vulpis are extremely resistant to adverse environmental conditions and to cleaning agents. Some sources suggest using a flame thrower to optimize egg destruction!