Trichuris felis

Trichuris felis

<p align="CENTER"><span style="font-size: large;"><i><b>Trichuris</b></i></span><span style="font-size: large;"><i><b>felis </b></i></span><span style="font-size: large;"><b>(Diesing, 1851) Diaz-Ungria, 1963)</b></span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>ETYMOLOGY:</b></span><span style="font-size: medium;"> The genus name </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;">, which may be translated as "hair tail," is actually a misnomer. A more appropriate name is </span><span style="font-size: medium;"><i>Trichocephalus</i></span><span style="font-size: medium;"> or </span><span style="font-size: medium;"><i>Trichocephalos</i></span><span style="font-size: medium;"> ("hair head"), nomenclature that is employed in Russia and in certain countries of eastern Europe. </span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>SYNONYMS: </b></span><span style="font-size: medium;">See history.</span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>HISTORY:</b></span><span style="font-size: medium;"> In 1851, Diesing described a species of </span><span style="font-size: medium;"><i>Trichocephalus</i></span><span style="font-size: medium;"> (</span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;">) from a tiger-cat in Brazil. He named the parasite </span><span style="font-size: medium;"><i>Trichocephalus</i></span><span style="font-size: medium;"><i>felis</i></span><span style="font-size: medium;">; however, the only description that he gave was that it was about 2 cm in length. Almost all other authors either ignore this species or regard it as differing from the trichurid of the domestic cat. Two species of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;">, </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>campanula</i></span><span style="font-size: medium;"> and </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>serrata</i></span><span style="font-size: medium;">, were described from the domestic cat in Brazil by von Linstow in 1879 and 1889, respectively. In the case of </span><span style="font-size: medium;"><i>T. campanula</i></span><span style="font-size: medium;">, no complete male worm was recovered. In 1923 Urioste, a Brazilian, concluded that </span><span style="font-size: medium;"><i>T. serrata</i></span><span style="font-size: medium;"> was the only valid species; however, Baylis pointed out that there were considerable discrepancies between von Linstow's measurements of </span><span style="font-size: medium;"><i>T. serrata</i></span><span style="font-size: medium;"> and those of Urioste. Urioste's measurements agreed very closely with the original description of </span><span style="font-size: medium;"><i>T. campanula</i></span><span style="font-size: medium;">. Urioste included a complete description of the male worm (Clarkson and Owen, 1960). Dias-Ungria , after finding worms in a Felis tigrina in Venezuela compared what had been described up to this point in time. Until the worms are better described, there seems to be no reason not to give the name </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>felis</i></span><span style="font-size: medium;"> priority. Arenas et al. collected </span><span style="font-size: medium;"><i>T. serrata</i></span><span style="font-size: medium;"> from Cuba in 1934, and Vogelsang reported the infrequent finding of </span><span style="font-size: medium;"><i>T. campanula</i></span><span style="font-size: medium;"> in Venezuela (Enzie, 1951). </span></p> <p align="JUSTIFY"><span style="font-size: medium;"> More recently, reports of adult feline whipworms have been made in Australia (Holmes and Kelly, 1972, Kelly, 1973, Ng and Kelly, 1975a). Whenever others have reported finding eggs of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"> in the feces of cats in various localities throughout the world, it is highly probable that these reports were due to mistaken identification of capillarid eggs (Enzie, 1951).</span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>GEOGRAPHIC DISTRIBUTION:</b></span><span style="font-size: medium;"> The feline whipworm is an extremely rare parasite, demonstrating a diverse geographic range. Sporadic reports of feline trichuriasis have been made from across the United States (Lillis, 1967, Burrows, 1968, Hass, 1973). Adult feline whipworms have been recovered from Madison, Wisconsin (Hass 1976) and from Miami, Florida (Hass, 1978, Hass and Meisels, 1978), the Bahama Islands (Clarkson and Owen, 1959), Cuba, and Venezuela in the Americas, from Switzerland and Poland (the former East Prussia) in Europe (Enzie, 1951), and from Australia (Holmes and Kelly, 1972, Kelly, 1973, Ng and Kelly, 1975a). </span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>LOCATION IN HOST: </b></span><span style="font-size: medium;">Members of the genus parasitize the cecum and colon. </span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>IDENTIFICATION: </b></span><span style="font-size: medium;">The whipworm is composed of a thin, filamentous anterior end (the "lash" of the whip) and a thick posterior end (the whip's handle). Adult feline whipworms possess this unique whip shape (Hendrix, </span><span style="font-size: medium;"><span style="text-decoration: underline;">et</span></span><span style="font-size: medium;"><span style="text-decoration: underline;">al</span></span><span style="font-size: medium;">., 1987). </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>campanula</i></span><span style="font-size: medium;"> has been reported to be 20.5 to 38.0 mm long while </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>serrata</i></span><span style="font-size: medium;"> has been reported to be 38.0 to 49.5 mm long (Hass and Meisels, 1978, Ng and Kelly, 1975a). However, for the present, it is best to just consider that these worms are probably less than 5 cm in length.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"> The egg of the feline whipworm may be described as being "trichinelloid" (Campbell, 1991) or "trichuroid," possessing a thick, yellow-brown, symmetrical shell with polar plugs at both ends and is unembryonated (not larvated) when laid (Hendrix, et al., 1987). The eggs of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>campanula</i></span><span style="font-size: medium;"> described by Hass and Meisels (1978) averaged 63 to 85 µm by 34 to 39 µm; while those of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>serrata</i></span><span style="font-size: medium;"> described by Ng and Kelly (1975a) averaged 54 by 40 µm.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"> It is important to remember that </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>felis</i></span><span style="font-size: medium;"> eggs may be easily confused with those of </span><span style="font-size: medium;"><i>Eucoleus</i></span><span style="font-size: medium;"><i>aerophilus</i></span><span style="font-size: medium;">, </span><span style="font-size: medium;"><i>Aonchotheca</i></span><span style="font-size: medium;"><i>putorii</i></span><span style="font-size: medium;">, and </span><span style="font-size: medium;"><i>Pearsonema</i></span><span style="font-size: medium;"><i>feliscati</i></span><span style="font-size: medium;">. It is also easy to confuse the eggs of the feline trichurids with the eggs of members of the genus </span><span style="font-size: medium;"><i>Anatrichosoma</i></span><span style="font-size: medium;">. The eggs of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"> and the capillarids are unembryonated while those of </span><span style="font-size: medium;"><i>Anatrichosoma</i></span><span style="font-size: medium;"> contain a larva. </span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>LIFE CYCLE: </b></span><span style="font-size: medium;">Nematodes of the genus </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"> are parasites of the large intestinal mucosal epithelium. In this site, the adult worms live, feed, and move slowly. Adult female whipworms are oviparous, producing typical double operculated eggs that pass to the external environment each day in the host's feces. In spite of adverse environmental conditions, whipworm eggs are markedly resistant to the elements and may remain viable in the soil for months or even years under optimal conditions. While in the external environment, the egg develops to the stage which contains the infective larva.</span></p> <p align="JUSTIFY"><span style="font-size: medium;"> The eggs of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>campanula</i></span><span style="font-size: medium;"> embryonate within a 3-week period (Hass and Meisels, 1978). Using eggs from a case in Miami,FLorida, USA, these authors experimentally infected four cats, and three eventually shed eggs in their feces, with prepatent periods of 62, 76, and 91 days. We know almost nothing about how or where these worms develop within the intestine of the cat, although based on work with the mouse and canine forms, it is assumed that development all takes place within the intestinal mucosa.</span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>CLINICAL PRESENTATION AND PATHOGENESIS:</b></span><span style="font-size: medium;"> There have been numerous reports of whipworm infections in cats; however, these reports were primarily the results of fecal flotation procedures. There have been no descriptions of clinical signs or pathology associated with feline trichuriasis. Prescott (1984) states that the pathogenesis of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"> species in the cat is unknown since heavy infections have not been recorded. Actual recovery of feline whipworms from cats at necropsy is rare; the maximum number of worms recovered from any one cat is reported at six (Ng and Kelly, 1975a). </span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>TREATMENT: </b></span><span style="font-size: medium;">Prescott (1984) recommends the use of fenbendazole (50 mg/kg once a day for three consecutive days to treat whipworms in the cat. This dosage was extrapolated from the dosage for the dog. </span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>DIAGNOSIS:</b></span><span style="font-size: medium;"> The egg of the feline whipworm possesses a thick, yellow-brown, symmetrical shell with polar plugs at both ends and is unembryonated (not larvated) when laid. The eggs of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>campanula</i></span><span style="font-size: medium;"> average 63 to 85 mm by 34 to 39 mm; those of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>serrata</i></span><span style="font-size: medium;"> average 54 by 40 mm (Hass and Meisels, 1978, Ng and Kelly, 1975a). </span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>EPIZOOTIOLOGY:</b></span><span style="font-size: medium;"> Infected domestic cats may serve as carriers. The exact role of wild Felidae (Cameron, 1936, Prescott, 1984) in the epizootiology of feline trichuriasis has not been determined.</span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>HAZARDS TO OTHER ANIMALS: </b></span><span style="font-size: medium;"> Although whipworms parasitize the lower bowel of a variety of both domestic and wild animals, these helminths are extremely host specific (Soulsby, 1982). There have been reports of the presence of the feline trichurids in larger members of the Felidae family (Cameron, 1936, Prescott, 1984).</span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>HAZARDS TO HUMANS:</b></span><span style="font-size: medium;"> Human infections with feline trichurids have not been recorded in the literature (Ng and Kelly, 1975b). Although canine trichurids have been associated with human infections worldwide, the rarity of infection and low parasite numbers in cats makes the role of the cat of little importance in this zoonosis (Prescott, 1984).</span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"><span style="font-size: medium;"><b>CONTROL/PREVENTION:</b></span><span style="font-size: medium;"> Effective control of feline whipworms involves proper diagnoses, therapy and sanitation of the cattery. To prevent reinfection, one must remove feces daily from the litterbox. Overcrowding of cats should be avoided in the cattery. Confining many animals to a small area increases environmental contamination and encourages transmission.</span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"></p> <h2 class="western"><span style="font-size: medium;">LITERATURE CITATIONS</span></h2> <p align="JUSTIFY"><span style="font-size: medium;">Burrows RB. 1968. Internal parasites of dogs and cats from central New Jersey. Bull NJ Acad Sci 13:3-8.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Cameron TWM. 1937. Studies on the endoparasitic fauna of Trinidad mammals V. Further parasites from the ocelot. Can J Res 15:24-27.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Campbell BG. 1991. </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"> and other trichinelloid nematodes of dogs and cats in the United States. Comp Cont Ed Pract Vet 13:769-779, 801.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Clarkson MJ and Owen LN. 1959. The parasites of domestic animals in the Bahama Islands. Ann Trop Med Parasitol 53:341-346.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Clarkson MJ and Owen LN. 1960. The species of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"> in the domestic cat. J Helminthol 34:319-322.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Enzie FD. 1951. Do whipworms occur in domestic cats in North America? J Am Vet Med Assoc 119:210-213. </span></p> <p align="JUSTIFY"><span style="font-size: medium;">Hass DK. 1973. Do whipworms occur in cats?. Feline Prac 3(4):36-37.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Hass DK. 1976. Whipworm reports requested (Letter). Feline Prac 6(1):5. </span></p> <p align="JUSTIFY"><span style="font-size: medium;">Hass DK. 1978. Feline whipworms do exist. Feline Prac 8(2):31-32. </span></p> <p align="JUSTIFY"><span style="font-size: medium;">Hass DK and Meisels LS. 1978. </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>campanula</i></span><span style="font-size: medium;"> infection in a domestic cat from Miami, Florida. Am J Vet Res 39:1553-1555. </span></p> <p align="JUSTIFY"><span style="font-size: medium;">Hendrix CM, Blagburn BL, and Lindsay DS. 1987. Whipworms and intestinal threadworms. Vet Cl N Am. 17:1355-1375. </span></p> <p align="JUSTIFY"><span style="font-size: medium;">Holmes PR and Kelly JD. 1972. Occurrence of the genus </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"> in the domestic cat. Aust Vet J 48:535.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Kelly JD. 1973. Occurrence of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>serrata</i></span><span style="font-size: medium;"> von Linstow, 1879 (Nematoda: Trichuridae) in the domestic cat (</span><span style="font-size: medium;"><i>Felis</i></span><span style="font-size: medium;"><i>catus</i></span><span style="font-size: medium;">) in Australia. J Parasitol 59:1145-1156.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Lillis WG. 1967. Helminth survey of dogs and cats in New Jersey. J Parasitol 53:1082-1084. </span></p> <p align="JUSTIFY"><span style="font-size: medium;">Ng BKY and Kelly JD. 1975a. Isolation of </span><span style="font-size: medium;"><i>Trichuris</i></span><span style="font-size: medium;"><i>campanula</i></span><span style="font-size: medium;"> von Linstow, 1889 from Australian cats. Aust Vet J 51:450-451.</span></p> <p align="JUSTIFY"><span style="font-size: medium;">Ng BKY and Kelly JD. 1975b. Anthropozoonotic helminthiases in Australasia: Part 3 - Studies on the prevalence and public health implications of helminth parasites of dogs and cats in urban environments. Int J Zoo 2:76-91. </span></p> <p align="JUSTIFY"><span style="font-size: medium;">Prescott CW. 1984. </span><span style="font-size: medium;"><span style="text-decoration: underline;">Parasitic Diseases of the Cat in Australia</span></span><span style="font-size: medium;">. Post-graduate Foundation in Veterinary Science. Sydney. . 112 pp.</span></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"></p> <p align="JUSTIFY"></p>