Histopathological alterations in psoroptic mange caused by Psoroptes cuniculi (Delafond, 1859) in goats

Resumo

With the aim to study the histologic lesions caused by Psoroptes cuniculi, the ears of 15 adult goats were collected in a slaughter house in the city of Patos, state of Paraíba, in the Brazilian semiarid region. Five goats had crusts and exudates in the external ears and were infested by 21 to 189 mites in each ear. Another 10 goats were asymptomatic, five of which had 14 to 39 mites and five of which were non-infested. From the five goats with clinical signs, three presented moderate macroscopic lesions with cerumen and dry crusts in both ears, affecting the pinna and ear canal. Two other goats presented mild lesions, characterized by exudates in the pinna without crust formation. The histologic lesions included varying degrees of parakeratotic hyperkeratosis, orthokeratotic hyperkeratosis, acanthosis, hypergranulosis, spongiosis, and dermatitis, with rare eosinophils. P. cuniculi were observed in the ear canal, occasionally in contact with the stratum corneum, but without causing traumatic lesions in the epithelium, which suggests that the lesions occur through a mechanical effect due to the presence of the mites together with the exudates, cerumen, and keratin residues.