First report of Dermatophilus congolensis dermatitis in dairy cows in Shiraz, Southern Iran

Skin lesions were found in two 3-4-year-old Holstein cows in a dairy farm in Shiraz. Lesions were distributed mostly around the neck, forelimbs, hindlimbs, and bilateral of midline portion and varied from nodule-like structure to patch with extensive accumulation of crust. Skin scraping samples were taken from each animal and direct smears were prepared, stained with Giemsa and observed under a light microscope. Some scabs were cultured and incubated both aerobically and anaerobically. Cultured smears were Gram stained and the morphology of isolates were studied. The diagnosis of dermatophilosis was made on the basis of clinical signs, skin lesions and morphological characteristics of the isolates, In this study, the infection could be related to insect population density during the outbreak and exposure to ticks which were observed in the animal environment. Rain scald in the region, especially in the late August and September could be a predisposing factor for flare-up of the infection. This is the first report of dermatophilosis in cattle in Shiraz, southern Iran.