Background: The anthelmintic efficacy of the 0.5% w/v topical formulation of eprinomectin (EPN), EPRINEX�®\nPour-on (Merial) when administered at 1 mg/kg body weight was evaluated in sheep in two dose confirmation\nlaboratory studies and one multicenter field study. In addition, the pharmacokinetics of EPN when administered\nat that dosage to adult sheep was determined.\nResults: In the two dose confirmation studies, which included 10 sheep each, sheep treated with topical EPN\nhad significantly (p < 0.05) fewer of the following nematodes than the untreated sheep with overall reduction of\nnematode counts by >99%: adult Dictyocaulus filaria, Haemonchus contortus, Teladorsagia circumcincta(pinnata/\ntrifurcata), Trichostrongylus axei, T. colubriformis, T. vitrinus, Cooperia curticei, Nematodirus battus, Strongyloides\npapillosus, Chabertia ovina and Oesophagostomum venulosum, and inhibited fourth-stage Teladorsagia larvae.\nA total of 196 sheep harboring naturally acquired gastrointestinal nematode infections were included in the field\nefficacy study at two sites each in Germany (48 Merino x Ile de France lambs, 52 adult Merino females) and in\nItaly (adult male and female Bagnolese, Lacaune, Lacaune x Bagnolese, Bagnolese x Sarda sheep; 48 animals per\nsite). Animals were blocked on pre-treatment body weight and within each block, one animal was randomly\nassigned to the control (untreated) group and three animals were randomly assigned to be treated with topical\nEPN. Examination of feces 14 days after treatment demonstrated that, relative to the controls, topical EPN-treated\nsheep had significantly (p < 0.0001) lower strongylid egg counts. Reduction was â�¥97% at each site and 98.6%\nacross all sites.\nPharmacokinetics of EPN following single treatment with topical EPN were determined in eight ~4.5 year old\nfemale Merino cross sheep based on the analysis of plasma samples which were collected from two hours\nto 21 days following treatment. The main pharmacokinetic parameters were: Cmax 6.20 �± 1.71 ng/mL, AUClast\n48.8 �± 19.2 day*ng/mL, Tmax 3.13 �± 2.99 days and T1/2 6.40 �± 2.95 days.\nNo treatment-related health problems or adverse drug events were observed in any study.\nConclusion: These studies demonstrated 0.5% w/v EPN administered topically at 1 mg/kg body weight to be\nhighly efficacious against a broad range of ovine gastrointestinal nematodes and D. filaria lungworms and well\ntolerated by sheep of different ages, breeds, gender and physiological status.
Loading....