The prevalence of anthelmintic resistance of horse strongyles in The Netherlands.
A survey to determine the prevalence of anthelmintic resistance of horse strongyles was carried out with 616 horses on 22 farms. The tested drugs were cambendazole, pyrantel pamaote and ivermectin. Based on egg count reduction tests the efficacy of cambendazole varied from 0% to 93% and of pyrantel from 93% to 100%. Ivermectin treatments were 100% effective on all farms. Larval cultures after cambendazole treatments revealed exclusively cyathostome larvae. After pyrantel treatments besides cyathostome larvae other types of larvae were also found. After ivermectin treatments only a few cyathostome larvae were observed. It can be concluded that benzimidazoleresistance of cyathostomes is very common and widespread in the Netherlands. This means that benzimidazoles and pro-benzimidazoles should be excluded for strategic use in horses.
Boersema
J H
JH
Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
Borgsteede
F H
FH
Eysker
M
M
Elema
T E
TE
Gaasenbeek
C P
CP
van der Burg
W P
WP
D000818:Animals; D002159:Cambendazole / Q000494:pharmacology / Q000627:therapeutic use*; D004351:Drug Resistance; D005243:Feces / Q000469:parasitology; D006736:Horses; D007559:Ivermectin / Q000494:pharmacology / Q000627:therapeutic use*; D007814:Larva / Q000187:drug effects; D009426:Netherlands; D010270:Parasite Egg Count / Q000662:veterinary; D011716:Pyrantel Pamoate / Q000494:pharmacology / Q000627:therapeutic use*; D011897:Random Allocation; D013319:Strongyle Infections, Equine / Q000188:drug therapy* / Q000469:parasitology; D013320:Strongyloidea / Q000187:drug effects*
D002159:Cambendazole; D007559:Ivermectin; D011716:Pyrantel Pamoate