Ulcerative cheilitis in a rhesus macaque.

A 2-year-old, female, simian immunodeficiency virus E543-infected rhesus macaque (Macaca mulatta) was presented for necropsy following euthanasia due to a history of diarrhea, weight loss, and a small, round ulcer along the left labial commissure. Histopathologic examination of the ulcer revealed infiltration by large numbers of degenerate and nondegenerate neutrophils and macrophages admixed with syncytial epithelial cells. Rare epithelial cells contained herpetic inclusion bodies. These cells stained positive for Human herpesvirus 1 via immunohistochemistry, and DNA sequencing confirmed the presence of closely related Macacine herpesvirus 1 (B virus).