title: The response of Awassi sheep to re-infection with Haemonchus contortus larvae.
abstract: The response of Awassi sheep to primary infection with 10 000 Haemonchus contortus larvae and subsequent challenge with 20 000 larvae was studied. Two types of response to re-infection were observed. The first, characterized by a sharp decline in egg counts, progressive improvement in packed cell volume (PCV) and a marked loss of adult worms and challenge larvae, was considered as self-cure and protection. In the second type of response there was a temporary decline in egg counts, no improvement in PCV and necropsy findings indicated hyper-infection with challenge larvae.
mesh_terms: D000818:Animals; D006188:Haemonchiasis / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D006189:Haemonchus / Q000276:immunology; D006400:Hematocrit; D007493:Iraq; D007814:Larva / Q000276:immunology; D010270:Parasite Egg Count; D012008:Recurrence; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology / Q000469:parasitology*; D014252:Trichostrongyloidiasis / Q000662:veterinary*