Factors affecting the establishment of the caecal threadwormTrichostrongylus tenuisin red grouse (Lagopus lagopus scoticus)

Abstract

SummaryThe resistance of captive reared red grouse toTrichostrongylus tenuiswas measured as the proportion of ingested infective 3rd-stage larvae which failed to develop to adult worms. Individual grouse showed wide, repeatable variations in resistance. Seasonal variations may also have occurred. Red grouse acquired little or no effective immunity to reinfection after challenge with a single dose of infective larvae. In trickle-dosed grouse, however, adult worms weakly inhibited the establishment of incoming larvae in an intensity-dependent fashion. Despite this, the proportion of larvae established in trickle infections was similar to that in single-dose challenges.