Anthelmintic efficacy of an oral formulation of Aurixazol against gastrointestinal nematodes of naturally and experimentally infected sheep

As a result of the need to develop new active principles for the control of endoparasites in ruminants, the present in vivo study evaluated a formulation containing 24% Aurixazol (48 mg/kg), a parasiticide molecule based on disophenolate of levamisole. Two experiments were conducted: one evaluating the anthelmintic efficacy of 24% Aurixazol (48 mg/kg) against gastrointestinal nematodes in naturally infected sheep, compared to an association of ivermectin (0.2 mg/kg) + albendazole (5.0 mg/kg) + levamisole (7.5 mg/kg) (IAL), and a second one which evaluated the persistent efficacy of the same formulation against immature stages (L4) and adults of Haemonchus contortus in experimentally infected animals. In experiment I, against H. contortus, the formulation of Aurixazol and the IAL association reached efficacies (arithmetic means) of 99.32% and 96.11%, respectively. For Trichostrongylus colubriformis, the efficacy values were 88.92% and 98.08% for Aurixazol and the IAL association, respectively. Both formulations were totally effective against Oesophagostomum columbianum (100%). The results of the statistical analysis demonstrated that the mean parasitic burden of treated animals was significantly different (P ≤ 0.05) compared to the average number of helminths diagnosed in animals from the control group for H. contortus, T. colubriformis and O. columbianum. Comparing only the treated groups, it was possible to verify that the average number of H. contortus recovered from animals treated with Aurixazol was different (P ≤ 0.05) when compared to the mean amount recovered from sheep treated with the IAL association. When evaluating the prevention of H. contortus infection in experiment II, Aurixazol did not present preventive efficacy. Up until 21 days after treatment the groups treated with Aurixazol contained less adults and L4 of H. contortus (P ≤ 0.05) when compared to the non-medicated control group. However, future studies will be necessary to assess the effectiveness of Aurixazol against nematode strains resistant to levamisole and disophenol, but the efficacy results described in this study allow to state that Aurixazol can, associated with other measures, become an important tool in the control of sheep nematodes. © 2013.

Resistance of beef cattle of two genetic groups to ectoparasites and gastrointestinal nematodes in the state of São Paulo, Brazil

The resistance to infestations by ectoparasites and infections by gastrointestinal nematodes was studied in 45 animals (males and females) of two genetic groups: purebred Nelore (NI, n=28) and Three-Cross (1/2 Angus+1/4 Canchim+1/4 Nelore - TC, n=17). The animals were monitored for 24months, during which they were left to graze in tropical pastures without receiving treatment for parasites. Each month the animals were examined for infestations by external parasites, to count the numbers of cattle ticks Rhipicephalus microplus with diameter greater than 4.5mm present on the left side, horn flies (Haematobia irritans) present in the lumbar region and botfly larvae (Dermatobia hominis) present on the entire body. The H. irritans counts were performed with the aid of digital photographs. At the time of examination, fecal samples were collected to count the eggs per gram (EPG) and to perform coprocultures, and peripheral blood samples were drawn to determine the packed cell volume (PCV) and to count the eosinophils. For statistical analysis, the count data were transformed into log10 (n+1), where n is the number of parasites. For PCV, significant effects (P<0.05) were found for collection month (CO), genetic group (GG) and gender (SX), with means and respective standard errors of 41.5±0.65% for the NI animals, 39.3±0.83% for the TC, 41.5±0.72% for the females and 39.3±0.77% for the males. Regarding the eosinophil counts, only the effect of sex was significant (P<0.01), with means and respective standard errors of 926.0±46.2/μL, for males and 1088.0±43.8/μL of blood, for females. The NI animals presented lower mean counts for all the external parasites compared to the TC animals (P<0.01). For ticks, the transformed means followed by standard errors for the NI and TC animals were 0.06±0.01 and 0.34±0.02, while for horn flies these were 0.92±0.05 and 1.36±0.06 and for botfly larvae they were 0.05±0.03 and 0.45±0.05, respectively. The average EPG values were only influenced by CO (P<0.01). The coprocultures revealed the presence of the following endoparasites: Haemonchus spp., Cooperia spp., Oesophagostomum spp. and Trichostrongylus spp., the last in smaller proportion. There were no significant differences between the genetic groups for the endoparasite loads, except for Cooperia spp., which were present in greater number (P<0.05) in the NI group. The results obtained in this experiment confirm previous findings of greater susceptibility of the Nelore breed to Cooperia spp. and high resistance to ectoparasites. © 2013 Elsevier B.V.

Utilização do 'beta' - glucano sobre o desempemho produtivo, indicadores de estresse, perfil hematológico e sobrevivência do pacu (Piaractus mesopotamicus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da atividade de contração e evaziamento gástrico em ratos gastretomizados por biosusceptometria AC

Pós-graduação em Biologia Geral e Aplicada - IBB

Efeitos cardiorrespiratórios e motilidade gastrointestinal da infusão contínua de butorfanol em equinos anestesiados pelo isofluorano

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aplicação e contribuição da cromoendoscopia no trato digestório superior de cães, uilizando Lugol, Índigo Carmim e Azul de Metileno

Pós-graduação em Medicina Veterinária - FMVZ

Alterações morfológicas, apoptose e expressão de metaloproteinases no tecido laminar de equinos submetidos à obstrução intestinal experimental: efeitos da hidrocortisona

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do perfil antiinflamatório e analgésico, e dos efeitos colaterais da administração oral de meloxicam em equinos: avaliação física, laboratorial e gastroscópica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Intervenção nutricional do estudo do envelhecimento do trato gastrointestinal em cães

Pós-graduação em Medicina Veterinária - FCAV

Análise histopatológica e imunoistoquímica de encéfalo de cães com cinomose tratados com ribavirina

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da atividade da fibra alimentar de Typha angustifolia L. e des seus efeitos sinérgicos com a prednisolona no modelo de colite ulcerativa induzida por ácido trinitrobenzenosulfônico em ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da atividade preventiva da dieta enriquecida com banana verde (banana 'Nanica' Musa sp AAA) e de seus efeitos sinérgicos com a prednisolona no modelo de colite ulcerativa induzida por ácido trinitrobenzenosulfônico em ratos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do geraniol sobre a doença ulcerosa péptica experimental

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito antinociceptivo, gastrointestinal e na atividade locomotora espontânea da administração intravenosa e metadona em equinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Pesquisa de agentes virais de doenças hemorrágicas em cervídeos brasileiros: Imunodetecção de células-tronco tumorais em neoplasias mamárias caninas

Pós-graduação em Medicina Veterinária - FCAV