Prevalence and pathology of dermatophilosis in camels (Camelus dromedaries) in Iran.

Gross and histopathologic lesions of the integumentary system were studied in 103 camels (Camelus dromedarius) slaughtered in Yazd Province of Iran. Dermatophilosis was diagnosed in 14 (13.6%) of the studied camels. Grossly, patchy thickening of the skin with dark brown scabs or crusts were observed on the rump, flanks, abdomen, shoulders, and neck. A heavy infestation with brown hard ticks was present on the lesions in almost all of the affected camels. On parasitology examination, all the ticks were identified as Hyalomma spp. Histopathologic examination of the affected skins revealed prominent superficial thickening of the epidermis as orthokeratotic and parakeratotic hyperkeratosis, degenerating neutrophils, serous fluid, and bacterial filaments. A lot of keratinaceous debris associated with an exudate rich in neutrophils were seen as remarkable features of the lesions on the superficial epidermis. Dermal inflammation was mild with infiltration of mononuclear inflammatory cells, particularly lymphocytes, around superficial vessels. A Gram-positive filamentous organism which was divided into parallel rows of cocci was observed in the crusts by Brown and Brenn Gram stain. This is the first report of the occurrence of dermatophilosis in the camels of Iran. With regard to infestation of the lesions by Hyalomma spp., it seems that this tick may have an important role in the pathogenesis of dermatophilosis in the camels of this region.