Segurança clínica e atividade ectoparatiticida de uma nova alternativa terapêutica para bovinos à base de fipronil associado com clorpirifós

• Ano de defesa: 2020
• Autor(a) principal: Oliveira, Alex Roberto de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade de Franca; Brasil; Pós-Graduação; Programa de Mestrado em Ciência Animal; UNIFRAN
• Palavras-chave em Português: Medicina veterinária - Antiparasitários; Carrapato do boi; Ectoparasitoses; Eficácia anti-cuterebrida; Miíases; Mosca-dos-chifres; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA
• Link de acesso: https://repositorio.cruzeirodosul.edu.br/handle/123456789/1946

An unprecedented drug formulation for cattle containing fipronil 5% and chlorpyrifos 30%, administered topically (spray) was evaluated in five experiments against ectoparasites and a clinical safety study. The safety and clinical safety of the aforementioned formulation were assessed by clinical examinations, blood counts and biochemical measurements. To evaluate the tick activity, two tests were carried out, one using experimentally infested cattle and the other bovine naturally parasitized by Rhipicephalus (Boophilus) microplus. In the other three studies, the efficacy against Haematobia irritans, against larvae of Dermatobia hominis and Cochliomyia hominivorax in naturally infested cattle was evaluated. In the innocuity study, no significant changes (P <0.05), except for the CHCM, were verified in the hematological (hemogram) and biochemical parameters measured in cattle treated with a new association, until the 21st day after treatment. In studies assessing the tick effectiveness of the association fipronil 5% and chlorpyrifos 30% it was found that the product significantly reduced (P <0.005) the tick counts and reached efficacy rates above 95% in the natural test and in the controlled infestation (stable test), complying with the precepts of the Ministerial Ordinance (Ordinance 48, MAPA, 1997). Haematobia irritans showed efficacy greater than 90% from D1 to D35 days after treatment, reaching levels of 98% on days 1, 3 and 5 days after treatment. In relation to the control group, both formulations evaluated significantly reduced (P <0.001) the number of Haematobia irritans present in medicated cattle, from the 1st to the 49th days after treatment. Against Dermatobia hominis larvae, the drug association achieved efficacy rates greater than 90.0% effective from the 5th day after treatment, obtaining maximum effectiveness for 23 days and significantly reducing (P <0.05) the number of bernes, compared to the control group. In contrast to Cochliomyia hominivorax larvae, the test formulation reached maximum efficacy levels within 48 hours after preventive treatment and 24 hours in curative treatment. Therefore, according to the results obtained in the six experiments carried out, it can be said that the combination of fipronil 5% and chlorpyrifos 30% is an effective ectoparasiticidacide and can be safely administered, provided that the restrictions on use are respected. KEYWORDS: antiparasitic; ox tick; ectoparasitoses; anti-cuterebrity efficacy; myiasis; horn fly.