INVESTIGADORES
LANUSSE Carlos Edmundo
congresos y reuniones científicas
Título:
Nematodicidal drug combinations: a valid strategy for parasite control in cattle
Autor/es:
CANTÓN, C; CEBALLOS, L; MORENO, L; DOMINGUEZ, P; CANTÓN, L; LANUSSE, C; ALVAREZ, L
Lugar:
Leon
Reunión:
Congreso; 2nd COMBAR Working Groups Meeting; 2018
Institución organizadora:
COMBAR
Resumen:
In an attempt to manage anthelmintic resistance, nematodicidal drug combinationscould be considered as a valid strategy to delay resistance development,contributing to optimize control of resistant parasite populations. The rationalebehind using combinations is based on the fact that individual worms may have alower degree of resistance to a multiple component formulation (each chemicalwith a different mode of action/resistance) compared to that observed when asingle anthelmintic molecule is used. A pharmaco-parasitological assessment ofdifferent nematodicidal combinations was performed at different cattle commercialfarms in Argentina. Ivermectin(IVM)-ricobendazole(RBZ), IVM-levamisole(LEV) andRBZ-LEV combinations were assessed. The observed pharmacokinetic datademonstrated that the co-administration of two anthelmintics did not modify theplasma pharmacokinetic behaviour of either drug in cattle. The combinations werethe only treatments achieving 100% clinical efficacy, even when a highly IVMresistant Haemonchus spp. isolate was present. Overall, after combined treatmentsa therapeutic additive effect was observed under all susceptible/resistancescenarios. However, the efficacy of IVM-RBZ against nematodes resistant to IVMand RBZ was greater than an additive effect. Achieving the highest possible efficacyis a powerful argument for using combinations; since fewer resistant parasites willsurvive treatment, the diluting effect with susceptible unselected parasites inrefugia will be greater, and thus the development of resistance may be slowed.Additionally, the weight gain was significantly higher for the combination IVM-RBZin calves naturally infected with resistant nematodes. Overall, anthelminticcombinations could be useful to control gastrointestinal nematodes in cattle farms.However, any treatment decision should be based on a previous diagnosis andrational use of combinations according to the situation of each individual farm.