Occurrence of clinical dermatophilosis in zero-grazed dairy cattle

Abstract

Dermatophilosis was clinically diagnosed and confirmed by isolation of Dermatophilus congolensis in three cows in a herd of seven zero-grazed dairy cattle. The lesions observed were matting together of hair into small tufts (greasy crusts) and discrete circumscribed lesions covered with creamy greasy crusts. The matting of hair into small tufts was found all over the body, while the discrete circumscribed lesions were mostly found in the distal extremities, dewlap, brisket, flank and dorsal midline. The circumscribed crusty lesions were similar to those of Trichophyton verrucosum infections that occur in similar production systems in Kenya, in that they were thick, horny and raised above the skin surface. However, unlike Trichophyton verrucosum infections, the crusts were held in place by penetrating hairs. Treatment of the severely affected cow with a single intramuscular injection of long acting tetracycline (20 mg/kg) resulted in regression of the lesions within 4 weeks, while in the mildly affected animals; the lesions receded on their own. Significant clinical Dermatophilosis has not been previously reported in stall-fed dairy animals in Kenya.