Monepantel-based anthelmintic combinations to optimize parasite control in cattle

CANTÓN C.; CANTON, LUCILA; LIFSCHITZ, A.; DOMINGUEZ, PAULA; ALVAREZ, L.; CEBALLOS, L.; MATÉ L.; LANUSSE, C.; BALLENT, M.

INTERNATIONAL JOURNAL FOR PARASITOLOGY

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2023

0020-7519

Improvement in the use of existing anthelmintics is a high priority need for the pharmaco-parasitology research field, considering the magnitude and severity of the anthelmintic resistance as an important issue in livestock production. In the work described here, monepantel (MNP) was given alone or co-administered with either macrocyclic lactone (ML) or benzimidazole (BZ) anthelmintics to calves naturally infected with ML and BZ resistant gastrointestinal (GI) nematodes on two different cattle commercial farms. Both, pharmacokinetic (PK) and efficacy assessments were performed. On Farm A, male calves (n= 15 per group) were treated with either MNP orally (2.5 mg/kg), IVM subcutaneously (sc, 0.2 mg/kg), ricobendazole (RBZ) (sc, 3.75 mg/kg) or remained untreated. On Farm B, eight groups (n=15) of male calves received treatment with either: MNP, abamectin (ABM, oral, 0.2 mg/kg), RBZ (sc, 3.75 mg/kg), albendazole (ABZ, oral, 5 mg/kg), MNP+ABM, MNP+RBZ and MNP+ABZ. (All at the mentioned above routes and doses) or remained untreated. Seven (7) animals from each treated group (Farm B) were randomly selected to perform the PK study. MNP and its metabolite monepantel sulphone (MNPSO2) were the main analytes recovered in plasma after HPLC analysis. The combined treatments resulted in decreased systemic exposures of MNP parent drug compared to that observed after the MNP alone treatment (P