A small scale survey of ivermectin resistance in sheep nematodes using the faecal egg count reduction test on samples collected from Scottish sheep.
Thirty-eight sheep flocks, predominantly from the south/central Scotland, were examined using a faecal egg count reduction test (FECRT) for the presence of ivermectin (IVM) resistant nematodes. Efficacies of less than 95%, 14-17 days post-treatment, were identified in 6 of 17 naturally grazing flocks where pre-treatment faecal egg counts were in excess of 150 eggs per gram. Efficacies on these IVM resistant farms ranged from 66 to 92%. One other suspected cases of IVM resistance was also identified in returned material. The larvae detected in post-treatment coprocultures from resistant flocks were from the genera Teladorsagia (4 from 6) and Trichostrongylus (2 from 6).
Bartley
D J
DJ
Department of Parasitology, Moredun Research Institute, Pentland Science Park, Bush Loan, Penicuik EH26 0PZ, UK. dave.bartley@moredun.ac.uk
Donnan
A A
AA
Jackson
E
E
Sargison
N
N
Mitchell
G B B
GB
Jackson
F
F
D000818:Animals; D000977:Antiparasitic Agents / Q000494:pharmacology*; D004351:Drug Resistance; D005243:Feces / Q000469:parasitology; D005260:Female; D007559:Ivermectin / Q000494:pharmacology*; D008297:Male; D010270:Parasite Egg Count / Q000662:veterinary*; D021261:Parasitic Sensitivity Tests / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy / Q000469:parasitology*; D016896:Treatment Outcome
D000977:Antiparasitic Agents; D007559:Ivermectin