New approach for the strategic control of gastrointestinal nematodes in grazed beef cattle during the growing phase in central Brazil.

We evaluated the effect of different treatment protocols against gastrointestinal nematodes in Nelore beef cattle during the growing phase in the municipality of Terenos, MS, in central Brazil from May 2013 to April 2014 and from May 2014 to April 2015. Ninety-six Nelore calves were kept on Brachiaria brizantha grass during each trial period and were distributed into six experimental groups (replicate paddocks for each group) based on live weight and the number of eggs per gram of feces (EPG): T1 (control)-treated in May, July and September with a saline solution; T2-treated in May and November with 700 µg/kg doramectin; T3-treated in May (doramectin), July (4.7 mg/kg levamisole phosphate) and September (doramectin); T4-treated in May (doramectin), July (200 µg/kg moxidectin) and September (doramectin); T5-treated in May (doramectin), August (levamisole phosphate) and November (doramectin) and T6-treated in May (doramectin), August (moxidectin) and November (doramectin). The calves were weighed and feces were collected (for faecal culture and EPG counts) from calves every 28 days, concomitantly with the collection of forage samples. The efficacies of doramectin, moxidectin and levamisole were low, at 69.2, 65.9 and 69.4% in the first and 13.8, 92.6, and 76.5% in the second experimental periods, respectively, but only the untreated animals lost weight during the dry season. Final weight gains did not differ significantly (p>0.05) among the animals in T2 (120.8 kg), T3 (131.4 kg), T4 (131.2 kg) and T5 (134.4 kg). T6 was the only group with a significantly higher final weight gain (140.9 kg) compared to the protocol with two annual dosages (T2). The weight gain was 31.9% higher in T6 than in the untreated animals (T1). None of the protocols affected the number of larvae on the pasture. Body weight was significantly and negatively (r=-0.65) correlated with EPG counts, which were significantly lower in June (T2, T3, T4 and T6), August (T3), September (T5 and T6), October (T5) and November (T5 and T6). Haemonchus, Cooperia, Trichostrongylus and Oesophagostomum were identified. Treatments in May and November, the most common practice in Brazil, did not increase the final weight gain, so an additional and intermediate treatment during the dry season (August) is recommended.

Microfilaremia by Cercopithifilaria bainae in a dog from the central western region of Brazil: case report / Microfilaremia por Cercopithifilaria bainae em um cão da região Centro-Oeste do Brasil: relato de caso

Cercopithifilaria bainae is a nematode belonging to the family Onchocercidae that parasitizes the subcutaneous tissue of dogs. Its transmission occurs through the tick Rhipicephalus sanguineus and its geographical distribution overlaps that of this vector. The present study reports the detection of microfilaremia by C. bainae in an eight-year-old male dog that presented anorexia, hyperthermia, motor incoordination, mydriasis, a nodule in the left testicle and concomitant infection by Ehrlichia sp. Blood samples were analyzed using microscopy, PCR and DNA sequencing. Microfilariae measuring 150±5.5µm in length and 7±1.8µm in width were retrieved. The DNA sequence exhibited 98% identity with C. bainae sequences available in Genbank. This is the first report of microfilaremia by C. bainae in a dog in the central western region of Brazil.(AU)

Cercopithifilaria bainae é um nematoide pertencente à família Onchocercidae, que parasita o tecido subcutâneo de cães. Sua transmissão ocorre pelo carrapato Rhipicephalus sanguineus, e sua distribuição geográfica se sobrepõe ao espalhamento desse vetor. O presente estudo relata a detecção de microfilaremia por C. bainae em um cão macho de oito anos que apresentava anorexia, hipertermia, incoordenação motora, midríase e nódulo no testículo esquerdo e infecção concomitante por Ehrlichia sp. A coleta de sangue foi realizada, e o material analisado por meio dos exames de microscopia, PCR e sequenciamento de DNA. Microfilárias medindo 150±5,5µm de comprimento e 7±1,8µm de largura foram recuperadas. A sequência de DNA obtida mostrou 98% de identidade com sequências de C. bainae disponíveis no Genbank. Este é o primeiro relato de microfilaremia de C. bainae em um cão na região Centro-Oeste do Brasil.(AU)

Molecular identification of Ehrlichia sp. in a beef cattle from Brazilian Cerrado - case report / Identificação molecular de Ehrlichia sp em um bovino do Cerrado brasileiro - relato de caso

Ehrlichia infections in cattle are frequent in Africa but have also been reported in Brazil and North America. This paper reports natural infection by Ehrlichia sp. associated with Babesia bigemina and Anaplasma marginale in a calf in the municipality of Campo Grande, state of Mato Grosso do Sul, Brazil, presenting polioencephalomalacia. The molecular evidence, based on a fragment of the dsb gene, indicates a species of Ehrlichia genetically related to Ehrlichia canis and other species of the genus found in the tick Rhipicephalus (Boophilus) microplus and a calf from Brazil (99 to 100% identity). It was not possible to associate the clinical signs with Ehrlichia infection due to co-infections and histological evidence of another disease. However, the circulation of the bacteria in bovines in Brazilian Cerrado was confirmed and more attention should be given to clinical suspicion of tick-borne pathogens in cattle to clarify the pathogenic potential of Ehrlichia sp.(AU)

Infecções por Ehrlichia em bovinos são frequentes na África, mas também foram relatadas no Brasil e na América do Norte. Este artigo relata uma infecção natural por Ehrlichia sp. associado a Babesia bigemina e Anaplasma marginale em um bezerro, no município de Campo Grande, Mato Grosso do Sul, Brasil, o qual apresentava polioencefalomalácia. A evidência molecular, baseada em um fragmento do gene dsb, indica uma espécie de Ehrlichia geneticamente relacionada a Ehrlichia canis e outras espécies do gênero encontradas no carrapato Rhipicephalus (Boophilus) microplus e em um bezerro do Brasil (99 a 100% de identidade). Não foi possível associar os sinais clínicos à infecção por Ehrlichia devido a coinfecções e evidências histológicas de outra doença. No entanto, a circulação da bactéria em bovinos no Cerrado brasileiro foi confirmada, e mais atenção deve ser dada à suspeita clínica de patógenos transmitidos por carrapatos em bovinos para esclarecer o potencial patogênico de Ehrlichia sp.(AU)