TY - JOUR
T1 - Effect of ivermectin on feeding by Haemonchus contortus in vivo
AU - Sheriff, James C.
AU - Kotze, Andrew C.
AU - Sangster, Nicholas C.
AU - Hennessy, Desmond R.
N1 - Imported on 12 Apr 2017 - DigiTool details were: Journal title (773t) = Veterinary Parasitology. ISSNs: 0304-4017;
PY - 2005
Y1 - 2005
N2 - While several in vitro studies have shown that the anthelmintic ivermectin inhibits feeding by parasites, the relevance of this putative site of action in vivo has not been demonstrated. For this study, techniques to measure feeding by Haemonchus contortus in vivo relied on the blood feeding characteristics of the worm, and utilised tritiated inulin administered to sheep intravenously and subsequently measured in worms recovered from abomasa. Nematodes recovered from sheep treated with ivermectin 4 h prior to the [3H]inulin administration showed equivalent feeding levels (over a 1 h period) to those recovered from sheep not treated with ivermectin. In addition, there was no difference in the radioactivity in nematodes of an ivermectin-susceptible and an ivermectin-resistant isolate recovered from individual sheep with concurrent infections after a dose with ivermectin. Ivermectin, therefore, had no effect on feeding by H. contortus in vivo under these experimental conditions. The results are discussed in relation to the dynamics of the expulsion of H. contortus from sheep following ivermectin treatment.
AB - While several in vitro studies have shown that the anthelmintic ivermectin inhibits feeding by parasites, the relevance of this putative site of action in vivo has not been demonstrated. For this study, techniques to measure feeding by Haemonchus contortus in vivo relied on the blood feeding characteristics of the worm, and utilised tritiated inulin administered to sheep intravenously and subsequently measured in worms recovered from abomasa. Nematodes recovered from sheep treated with ivermectin 4 h prior to the [3H]inulin administration showed equivalent feeding levels (over a 1 h period) to those recovered from sheep not treated with ivermectin. In addition, there was no difference in the radioactivity in nematodes of an ivermectin-susceptible and an ivermectin-resistant isolate recovered from individual sheep with concurrent infections after a dose with ivermectin. Ivermectin, therefore, had no effect on feeding by H. contortus in vivo under these experimental conditions. The results are discussed in relation to the dynamics of the expulsion of H. contortus from sheep following ivermectin treatment.
KW - Haemonchus contortus
KW - Inulin
KW - Ivermectin
KW - Nematode feeding
U2 - 10.1016/j.vetpar.2004.12.008
DO - 10.1016/j.vetpar.2004.12.008
M3 - Article
VL - 128
SP - 341
EP - 346
JO - Veterinary Parasitology
JF - Veterinary Parasitology
SN - 0304-4017
IS - 3-4
ER -