resumen

CANTON, C.1; CEBALLOS, L.1; MORENO, L.1; FIEL, C.2; DOMINGO YAGÜEZ, P.3; LANUSSE, C.1; ALVAREZ, L.1

Belen

Congreso; Congreso Brasilero de Parasitología Veterinaria; 2016

Asociación Brasilera de Parasitologia Veterinaria

Nematodicidal drug combinations could be a valid strategy to optimize parasite control, particularly in delaying the emergence of resistance and controlling parasite populations with existing resistanceThe main goal of the current trial was to study the clinical efficacy and the epidemiological impact of the eggs excreted to the pasture after the subcutaneous (SC) administration of ivermectin (IVM) and ricobendazole (RBZ) given both separately and co-administered to calves parasitized with resistant nematodes on 4 commercial cattle farms. On each farm, sixty (60) male calves naturally infected with gastrointestinal nematodes resistant to IVM were randomly allocated into four groups (n= 15): Control group: animals did not receive anthelmintic treatment; IVM group: animals were treated with IVM by the SC route (0,2 mg/kg); RBZ group: animals were treated with RBZ by the SC route (3,75 mg/kg); IVM+RBZ group: animals were treated by the SC route with IVM and RBZ (0,2 and 3,75 mg/kg, respectively). The clinical efficacy was determined by Faecal Egg Count Reduction Test (FECRT) at 15 days post-treatment. The excretion of eggs to the pasture was reported as the sum of eggs excreted per day by the 15 animals included in each experimental group. The results are presented as the mean average across all tests.The efficacies were 68% (IVM), 97% (RBZ) and 99% (IVM+RBZ).No significant differences were found between RBZ alone and combined with IVM in terms of clinical efficacy (P>0.05