Molluscum contagiosum in three horses

Suspected molluscum contagiosum was diagnosed in 3 horses in the Chingola district of Zambia. The horses were found to be suffering from a slow progressive skin disease with lesions on the chest, shoulders, inner and lateral aspects of the fore- and hindlimbs, the face, fetlocks, pasterns and on the lateral surfaces of the body. The lesions varied from 4 to 20mm in diameter, were hairless but covered by soft keratin projections which, when removed, left a raw elevated base tightly adherent to the epidermis. These lesions bled profusely when the animals were groomed. Older lesions were well circumscribed, raised above the surface, devoid of hair and after removal of grey-white keratin flakes, had a depigmented waxy appearance. Microscopically cytoplasmic inclusions containing many pox virions were found. Attempts at culturing the virus were unsuccessful.