title: Dose confirmation of moxidectin pour-on against natural nematode infections in lactating dairy cows.
abstract: The nematocidal effectiveness of moxidectin, administered topically at the rate of 500 mcg/kg BW, was determined for lactating dairy cows. Naturally infected animals were given either topical vehicle or moxidectin (Cydectin Pour-On Fort Dodge Animal Health) at the rate of 1 ml/10 kg BW (10 animals per treatment group), and sacrificed 14-18 days post-treatment for nematode enumeration. 100% efficacies were recorded for Ostertagia lyrata males, Cooperia punctata males and Oesophagostomum radiatum L4, with treatment group differences in geometric means significant (P < 0.05) for all. Populations of Trichostrongylus L4 and adult O. radiatum were also reduced by 100%, but low prevalence rates in the control animals precluded meaningful statistical inference. Nematode populations for which efficacies ranged from 96.7 to 99.6% (based on geometric means) and for which treatment group differences were significant (P < 0.05) included Ostertagia spp. adult females, inhibited L4 and developing L4, O. ostertagi adult males, Trichostrongylus axei adults and Cooperia spp. adult females. For all nematodes combined, moxidectin was 98.9% efficacious. In addition to exhibiting excellent nematocidal effectiveness, topical moxidectin was demonstrated to be safe, with animal health and milk production unaffected during the study.
authors.affiliation: Department of Animal Science, University of Arkansas, Fayetteville 72701, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Yazwinski
authors.forename: C
authors.initials: C
authors.lastname: Tucker
authors.forename: S
authors.initials: S
authors.lastname: Copeland
authors.forename: T
authors.initials: T
authors.lastname: Yazwinski
authors.forename: F
authors.initials: F
authors.lastname: Guerino
mesh_terms: D000018:Abomasum / Q000469:parasitology; D000287:Administration, Topical; D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000592:standards / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000592:standards / Q000627:therapeutic use; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology / Q000517:prevention & control*; D005260:Female; D007420:Intestine, Large / Q000469:parasitology; D007421:Intestine, Small / Q000469:parasitology; D007774:Lactation; D018942:Macrolides; D008297:Male; D009349:Nematode Infections / Q000517:prevention & control / Q000662:veterinary*; D009814:Oesophagostomiasis / Q000517:prevention & control; D009815:Oesophagostomum / Q000187:drug effects; D010028:Ostertagia / Q000187:drug effects; D010029:Ostertagiasis / Q000517:prevention & control / Q000662:veterinary; D010270:Parasite Egg Count / Q000662:veterinary; D015995:Prevalence; D011897:Random Allocation; D014251:Trichostrongyloidea / Q000187:drug effects; D014252:Trichostrongyloidiasis / Q000517:prevention & control / Q000662:veterinary
chemical_list: D000871:Anthelmintics; D000900:Anti-Bacterial Agents; D018942:Macrolides; C027837:moxidectin