An apparent outbreak of cutaneous papillomatosis in Merino sheep in Patagonia, Argentina

A retrospective study was performed on skin samples from an outbreak of cut aneous papillomatosis in Merino sheep that occurred in 1995. The samples we re processed for routine histology, electron microscopy and immunocytochemi stry for papilloma viruses. Particles of approximately 55 nm diameter were found in some nuclei of the stratum granulosum cells, while immunocytochemi stry gave positive staining of cell nuclei in this layer. This study confir ms that papillomas associated with papillomaviruses occur in sheep in Patag onia.