Eficácia e segurança clínica comparativa de duas formulações de aplicação tópica contendo 10% de fipronil no controle de ectoparasitos em cães e gatos

Abstract

The objectives of the present study were to evaluate the efficacy and clinical safety of a novel topical 10% fipronil on the control of Ctenocephalides felis felis on dogs and cats and Rhipicephalus sanguineus on dogs; residual efficacy of the fipronil formulation on dog s coat on the control of eggs, larvae and adults of C. felis felis; effect of dispersion of the tested formulation on adults of C. felis felis; and the influence of bathe on the efficacy of the novel formulation against fleas and ticks on dogs. Utilized animals were belong to the the Laboratory of Experimental Chemotherapy in Veterinary Parasitology (LECVP) from the Department of Animal Parasitology of the Institute of Veterinary of the Universidade Federal Rural do Rio de Janeiro or domiciliated ones. Fleas and ticks were gathered from colonies maintained in the LECVP. Methodologies were based on guidelines and the literature. Pulicide efficacy on cats was: 99.4; 100; 100; 95.1; 86.8 and 70% on days +2 +7, +14, +21; +28, +35 e +42, respectively. The efficacy against ticks on dogs was: 100; 100; 95.4; 90.2; 83.4 and 62.6% on days +2 +7, +14, +21; +28 e +35, respectively. Pulicide efficacy on dogs was: 100; 100; 100; 99.5; 99.8 and 91.6% on days +2 +7, +14, +21; +28 e +35, respectively. Those essays demonstrated satisfactory efficacy levels obtained by the formulation and expected residual period against reinfestations. Regarding the influence of shampooing on pulicide activity, the efficacy was 100% on days +3, +7, +14, +21 and +28; 98.4; 95 and 70.6% on days +35, +42 e +49, respectively for the group with only one bathe. The weekly shampooing group presented efficacy of 98.8; 100; 100; 100; 86.9 and 44.2% on days +3, + 7, +14, +21, +28, +35 and +42, respectively. Efficacy against ticks for the group shampooed once was 99.5; 100; 100; 91.8; 91.6; 70.9 and 63.2% on days +3, + 7, +14, +21, +28, +35 and +42, respectively. The weekly shampooing group presented efficacy of 100; 100; 99.1; 81.1; 58.9 e 41.% on days +2 +7, +14, +21; +28 and +35, respectively. Shampooing once did not affect the product s efficacy. Weekly bathes, despite showed satisfactory efficacy, presented shorter residual period. Regarding the in vitro trials to evaluate the residual activity against fleas, the following can be concluded: the adulticide efficacy varied from average to high until day +14; larvicide efficacy was irregular and presented short residual activity; efficacy against eggs was high and presented long residual activity. Regarding the in vitro essays to evaluate speed of kill the formulation was 100% effective within 16h until day +21 and, 24h on days +28 and +35, demonstrating long residual activity. Therefore, the topical 10% fipronil formulation presented, in general, satisfactory efficacy levels and residual activity on C. felis felis on cats and dogs and, R. sanguineus on dogs, comparable to the reference formulation found commercially, besides have presented the desirable clinical safety.