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The effect of immunosuppression with dexamethasone on Haemonchus contortus infections in genetically resistant Merino sheep
Author(s) -
PRESSON B.L.,
GRAY G.D.,
BURGESS S.K.
Publication year - 1988
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1111/j.1365-3024.1988.tb00253.x
Subject(s) - haemonchus contortus , biology , immunosuppression , abomasum , genotype , dexamethasone , immunology , veterinary medicine , helminths , gene , endocrinology , genetics , medicine , rumen , food science , fermentation
Summary The effect of immunosuppression with the glucocorticosteroid, dexamethasone, on the susceptibility to Haemonchus contortus infection of a highly resistant Merino genotype was investigated. Higher faecal egg counts, larger worm burdens and heavier worms were recorded in immunosuppressed wethers. The characteristic globule leucocyte infiltrate in the abomasum of resistant wethers (12‐month‐old castrated males) was absent in immunosuppressed animals. Treatment with dexamethasone abolished differences between resislanl and susceptible genotypes in faecal egg counts, worm weights, thymus weights and globule leucocyte responses to infection with H. contortus. These results suggest that an immunological basis underlies the high level of resistance to infection in the resistant genotype.