Psittacine beak and feather disease infected cells show a pattern of apoptosis in psittacine skin

Skin biopsies from 23 birds with psittacine beak and feather disease (PBFD) were examined by light and electron microscopy. Affected cells, preferenti ally found in the cell layers of the feather follicles, could be clearly id entified by the presence of intracytoplasmic virus inclusion bodies. Ultras tructurally, the degenerative process in these cells was morphologically su ggestive of apoptosis.