title: Primary and secondary infection of the domestic chicken with Trichostrongylus tenuis (Nematoda), a parasite of red grouse, with observations on the effect on the caecal mucosa.
abstract: The course of primary and secondary infections with Trichostrongylus tenuis in the domestic chicken was investigated. Primary infections were established after the administration of single and trickle doses of infective-stage larvae. The worm burden in the caeca was highest after a single dose of 500 infective-stage larvae; this gave a mean of 87 nematodes per bird on days 89 of infection, 20 nematodes on day 14 and 0 on day 28 of infection. Following trickle doses of 60, 100, 200, 300, 400 or 500 infective-stage larvae, there was a rise and then a fall in nematode egg output in all groups. In chickens given a primary dose of 500 infective-stage larvae followed 30 days later by a single secondary dose of 500 infective-stage larvae, the mean worm burden during the secondary infection rose to 57 nematodes on day 9 of infection and then fell rapidly to 18 nematodes on day 15 and to 2 on day 30. Scanning electron microscopy showed changes in the caeca of infected birds, with the caecal surface being covered in a layer of mucus from 12 days after infection. Ball of blood-stained mucus containing nematodes were observed in the caecal droppings from day 9 of infection onwards. It is concluded that chickens rapidly expel an established infection of T. tenuis, unlike the normal host, the red grouse.
authors.affiliation: Department of Pure and Applied Biology, University of Leeds.
authors.forename: H
authors.initials: H
authors.lastname: Watson
authors.forename: D L
authors.initials: DL
authors.lastname: Lee
authors.forename: P J
authors.initials: PJ
authors.lastname: Hudson
mesh_terms: D000818:Animals; D002429:Cecal Diseases / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D002432:Cecum / Q000469:parasitology / Q000648:ultrastructure; D002645:Chickens / Q000469:parasitology*; D005260:Female; D007411:Intestinal Diseases, Parasitic / Q000469:parasitology / Q000473:pathology / Q000662:veterinary; D007413:Intestinal Mucosa / Q000469:parasitology / Q000648:ultrastructure; D007814:Larva; D008297:Male; D008855:Microscopy, Electron, Scanning; D011201:Poultry Diseases / Q000469:parasitology* / Q000473:pathology; D014252:Trichostrongyloidiasis / Q000662:veterinary*; D014253:Trichostrongylosis / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D014254:Trichostrongylus / Q000502:physiology* / Q000648:ultrastructure