Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-26T00:58:17.257Z Has data issue: false hasContentIssue false

Inhibited development in Haemonchus contortus

Published online by Cambridge University Press:  06 April 2009

R. M. Connan
Affiliation:
School of Veterinary Medicine, Madingley Road, Cambridge

Extract

Inhibited development of Haemonchus contortus was studied in single experimental infections of worm-free lambs. Chilling of the infective larvae at + 4°C was without effect on the percentage of larvae subsequently becoming inhibited and a period of exposure to autumnal conditions was unnecessary to induce a high rate of inhibition. It was concluded that seasonal inhibition of H. contortus in East Anglia is brought about primarily by an environmental stimulus acting upon the preparasitic stages but that, unlike Obeliscoides cuniculi and Ostertagia ostertagi, this was not cold. It could be provided in a culture kept in the dark at 25 °C for 12 days. While the age of the host did influence the phenomenon, in that larvae were less inclined to inhibition in very young animals, it was concluded that this was not a primary factor in the aetiology.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1975

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Armour, J. (1970). Bovine Ostertagiasis: a review. Veterinary Record 86, 184–90.CrossRefGoogle ScholarPubMed
Armour, J. & Bruce, R. G. (1974). The inhibition of development of Ostertagia ostertagi – a diapause phenomenon. Parasitology 69, 161–74.Google Scholar
Armour, J., Jennings, F. W. & Urquhart, G. M. (1969). Inhibition of Ostertagia ostertagi at the early 4th larval stage. II. The influence of environment on host or parasite. Research in Veterinary Science 10, 238–44.CrossRefGoogle ScholarPubMed
Blitz, N. M. & Gibbs, H. C. (1972). Studies on the arrested development of Haemonchus contortus in sheep. I. The induction of arrested development. International Journal for Parasitology 2, 512.Google Scholar
Connan, R. M. (1971). The seasonal incidence of inhibition of development in Haemonchus. Research in Veterinary Science 12, 272–4.Google Scholar
Dineen, J. K., Donald, A. D., Wagland, B. M. & Offner, J. (1965). The dynamics of the host-parasite relationship. III. The response of sheep to primary infection with Haemonchus contortus. Parasitology 55, 515–25.Google Scholar
Fernando, M. A., Stockdale, P. H. G. & Ashton, G. C. (1971). Factors contributing to the retardation of development of Obeliscoides cunciuli in rabbits. Parasitology 63, 21–9.Google Scholar
Gibbs, H. C. (1967). Some factors involved in ‘the spring rise’ phenomenon in sheep. In The Reaction of the Host to Parasitism (ed. Soulsby, E. J. L.), pp. 160–74. Elwert University: Marburg Lahn.Google Scholar
Hutchinson, G. W., Lee, E. H. & Fernando, M. A. (1972). Effects of variations in temperature on infective larvae and their relationship to inhibited development of Obeliscoides cuniculi in rabbits. Parasitology 65, 333–42.Google Scholar
McKenna, P. B. (1973). The effect of storage on the infectivity and parasitic development of third-stage Haemonchus contortus larvae in sheep. Research in Veterinary Science 14, 312–6.CrossRefGoogle ScholarPubMed
Muller, G. L. (1968). The epizootiology of Helminth infestation in sheep in the Southwestern districts of the Cape. Onderstepoort Journal of Veterinary Research 35, 159–94.Google Scholar