ABSTRACT
This paper presents a hypothesis on the involvement of species of the genus Raillietia Trouessart in the pathology of parasitic otitis in domestic ruminants. The chelicerae and claws of the tarsi are structures that contribute significantly towards producing primary lesions. The movable digits of the chelicerae accidentally injure the epithelium that lines the ear canal, while the claws of the tarsi perforate the epithelium, allowing the mites to affix themselves while feeding. The lesions in the epithelium caused by the chelicerae and the claws favor multiplication of the bacteria that inhabit the ear canal, resulting in typical cases of otitis.
Neste trabalho apresentamos uma hipótese para explicar o envolvimento dos ácaros do gênero Raillietia na patogênese da otite parasitária em ruminantes domésticos. As quelíceras e unhas dos tarsos são estruturas que contribuem significativamente para produzir as lesões primárias no epitélio. Os dígitos móveis das quelíceras acidentalmente causam injúria no epitélio que reveste o canal auditivo, enquanto as unhas dos tarsos perfuram o epitélio para permitir a fixação dos ácaros durante sua alimentação. As lesões no epitélio causadas pelas quelíceras e unhas dos tarsos favorecem a multiplicação das bactérias que habitam o canal auditivo, resultando em casos típicos de otite.
ABSTRACT
Amblyomma scalpturatum Neumann has been reported in Brazil in the northern (States of Amazonas, Pará and Rondônia) and mid-western regions (States of Mato Grosso and Mato Grosso do Sul). It has been found in association with large and medium sized mammals, as Artiodactyla, Perissodactyla, Xenarthra and Carnivora. In this paper, this tick species is reported for the first time in the Brazilian states of Paraná and Roraima, southern and northern regions, respectively.