Detecção e tratamento de otite por Rhabditis blumi em bovinos da região Norte do Brasil

Abstract

RESUMO.-O presente estudo teve como objetivo descrever a ocorrência de otite parasitária causada por Rhabditis blumi em bovinos leiteiros de raça Gir de uma fazenda da região Norte do Brasil. Foram coletadas amostras de 42 bovinos por swab e lavado dos condutos auditivos externos (CAE). Ao exame clínico, 9,5% (4/42) dos bovinos apresentavam sintomatologia nervosa, como leve a moderada rotação da cabeça, apatia, flacidez dos lábios e ptose palpebral This study aimed to describe the occurrence of parasitic otitis caused by Rhabditis blumi in dairy cattle of the Gir race from a farm in northern Brazil. Forty-two samples were collected from cattle by swab washed from the external auditory canal (EAC). On clinical examination, in 71.4% (30/42) of the cattle the parasite was found in the cerumen of the ear canal, along with alopecia of head and hump caused by discomfort and itching of the auricular region. At microscopic analysis of material from the conjunctival sac the parasite was found in 90% (9/10) of the evaluated cattle. In addition, 9.5% (4/42) of the cattle showed nervous symptoms, such as mild to moderate rotation of the head, apathy, flaccid lips and unilateral ptosis, change in chewing and food accumulation in the oral cavity. Thirty cattle positive for Rhabditis spp. were randomly divided into three groups of 10 animals each: (G1) Cattle Control, (G2) Cattle treated with ivermectin 1% pour-on, and (G3) Cattle undergoing wash of the external auditory canal (EAC). Each treatment was repeated three times with intervals of seven days. In G1, 10 cattle remained infected throughout the study. In G2, 20% of the cattle were negative after the first two treatments, however were positive at the third evaluation. In G3, all cattle remained positive, but with decrease in parasite load. Identification by molecular analysis of amplified fragments through the expansion D2/D3 28S rDNA confirmed the presence of only Rhabditis blumi. Based on clinical, morphologic and molecular examination, it appears to be the first report of the occurrence of R. blumi infection in Gir cattle in the State of Pará, due to the purchase of cattle from areas where parasitic otitis has been diagnosed, as from Minas Gerais, to produce crossbred animals (Gir x Holstein). This emphasizes the importance of prior clinical examination by the veterinary service in order to transfer only healthy animals to other properties or regions. This appears also to be the first report on R. blumi infection of the conjunctival sac in cattle. Treatment with ivermectin in G2 did not produce clinical improvement.

Rhabditis spp., in the Espírito Santo, State of Brazil and evaluation of biological control

“…Following the methodology adopted by Barbosa et al (2016), with some modifications, the animals were restrained in an immobilizing "stock". Secretion present in the external auditory meatus (EAM) was collected with the swabs that consisted of a wooden stick with a tuft wrapped around the tip.…”

“…Parasitic otitis may be caused by nematodes and mites, which may be associated with bacteria (BOSSI et al, 2015). The nematode responsible for the disease belongs to the genus Rhabditis, which affects both ears, producing cerulean or purulent exudates (BARBOSA et al, 2016). It has been reported that the occurrence of this disease in almost all regions of Brazil is well documented (DUARTE et al, 2001), and also in the state of Espírito Santo (BELTRAME et al, 2011).…”

Distribution of cysts of Strongyluris sp. (Nematoda) in the pallial system of Achatina fulica Bowdich, 1822 from Vila Dois Rios and Vila do Abraão, Ilha Grande, Angra dos Reis, Rio de Janeiro

“…In terms of public health, A. fulica is a potential intermediate host of nematodes of medical importance, such as Angiostrongylus costaricensis Morera and Céspedes, 1971 and Angiostrongylus cantonensis (Chen, 1935), related to the abdominal and meningocerebral angiostrongyliasis (Thiengo et al, 2007;Maldonado Júnior et al, 2010). It can be also a potential both an intermediate and paratenic host of some parasites of wild animals species of Aelurostrongylus Cameron, 1927 (Thiengo et al, 2008;Oliveira et al, 2010) could parasite lung both domestic and wild cats (Ribeiro and Lima, 2001), Rhabditis Dujardin, 1845, that lodge in the external auditory canal of cattle, causing otitis (Martins Júnior, 1985;Campos et al, 2002;Thiengo, 2009;Barbosa et al, 2016) and Strongyluris Mueller, 1894, which are intestinal parasites mainly found in lizards (Kohn et al, 1973;Vicente et al, 1993;Rocha and Vrcibradic, 2003).…”

Avaliação do potencial nematicida in vitro de formulações comerciais à base de Bacillus spp

“…Entretanto, existem algumas espécies de importância veterinária: Rhabditis bovis é o principal causador de otite parasitária externa, amplamente encontrado em rebanhos da África e alguns países da América do Sul (CARDONA et al, 2010;MSOLLA 1993, OBATOLU, 1999. No Brasil, as espécies descritas foram Rhabditis freitasi, Rhabditis blumi, Rhabditis costai (BARBOSA et al, 2016;SILVA et al, 2016) que podem causar otite parasitária externa em bovinos das regiões tropicais (BARBOSA et al 2016;LEITE et al, 2013;SOBRAL et al, 2019). Em raros casos, nematoides do gênero Rhabditis podem infectar seres humanos e causar otite (TESCHNER et al, 2014) e diarreia (CAMPOS et al, 2002;MEAMAR et al, 2007;YE et al, 2002).…”

“…A raça Gir origina o Girolando, quando cruzada com o gado Holandês (SILVA et al, 2018). A raça Gir apresenta grande susceptibilidade à doença chamada otite parasitária externa, que tem como um dos principais agentes etiológicos no Brasil, nematoides do gênro Metarhabditis (BARBOSA et al, 2016, SILVA et al, 2016SOBRAL et al, 2019). A otite parasitária externa é identificada facilmente pela presença de secreção purulenta no pavilhão auricular, mas apresenta variados sintomas, desde portadores assintomáticos, até infecções no sistema nervoso e morte (CARDONA et al, 2012;DUARTE e HANDAM, 2004;LEITE et al, 2013).…”