Pharmacokinetics and efficacy of large ivermectin doses in lambs parasitized with resistant Haemonchus contortus.

ALVAREZ, L.; SUAREZ, G.; LIFSCHITZ, A.; CANTÓN, C.; CEBALLOS, L.; MORENO, L.; LANUSSE, C.

Perth

Conferencia; 24th International Conference of the World Association for the Advancement of Veterinary Parasitology; 2013

World Association for the Advancement of Veterinary Parasitology

Abstract: The main goals of the current work were: a) to assess the ivermectin (IVM) plasma disposition kinetics after its administration at the recommended, x5 and x10 times dose rates to lambs and, b) to compare the clinical efficacy of the same IVM dosages in lambs infected with an IVM-resistant strain of Haemonchus contortus. There was two separated trials, where IVM was administered either subcutaneously (Experiment I) or intraruminally (Experiment II). Each experiment involved twenty-four (24) lambs artificially infected with a highly resistant H. contortus strain. Animals were allocated into 4 groups (n=6) and treated with IVM at either 0.2 (IVMx1), 1 (IVMx5) or 2 mg/kg (IVMx10). Plasma samples were collected up-to 12 days post-treatment and analysed by HPLC. An untreated-control Group was included to assess the comparative anthelmintic efficacy of the different treatments. Parametric and non-parametric tests were used to compare the statistical significance of the results (P