Susceptibility to IVM in a field strain of Haemonchus contortus subjected to four treatments in a closed sheep–goat flock in Kenya
Date
2003Author
Gatongi, P M
Njoroge, J M
Scott, M E
Ranjan, S
Gathuma, J M
Munyua, W K
Cheruiyot, H
Prichard, R K
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Susceptibility to IVM (IVM) of “strain A” Haemonchus contortus which had been exposed to IVM four times over a 2-year period was compared to IVM susceptibility of “strain C” H. contortus which had no prior field exposure to IVM, by in vivo and in vitro methods. In vivo, the percentage reduction in faecal egg counts (FEC) and the total worm counts (TWC) were compared between control animals (lambs and kids) and animals treated with low dose IVM (20 μg/kg). In vitro susceptibility to IVM was evaluated by larval migration inhibition (LMI) after the two strains of H. contortus were exposed to different concentrations of IVM. The dose response, measured as the proportion of larvae inhibited from migrating, was used to estimate LD50. Although differences in response to IVM in the in vivo determinations were not significant, “strain A” H. contortus had a significantly higher LD50 than “strain C” in the LMI assay. Coincident with the conduct of the in vivo experiment, it was observed that “strain A” H. contortus established and survived better than “strain C” in the control lambs.
URI
http://www.sciencedirect.com/science/article/pii/S0304401702003187http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/32394
Citation
Gatongi, P.M et al(2003). Susceptibility to IVM in a field strain of Haemonchus contortus subjected to four treatments in a closed sheep–goat flock in Kenya. Veterinary Parasitology; 110(3-4):235-240Publisher
Department of Public Health, pharmacology and Toxicology, University of Nairobi
Subject
Haemonchus contortusIVM
Susceptibility
Resistance
Sheep
Goats
Larval migration inhibition
Faecal egg count reduction
Total worm count
Description
Journal article