Pox virus keratitis in a rabbit

A 10-month-old rabbit (Oryctolagus cuniculus ) developed a small rounded mass on the right medial cornea. The rabbit was killed and necropsied. The mass was firm, pale yellow, and approximately 0.75 cm in diameter. Light microscopy showed it to be composed of proliferative spindle-shaped and oblong cells of various sizes confined to the cornea and arranged beneath the corneal epithelium. These cells contained many unstained and some eosinophilic homogeneous droplets. The overlying corneal epithelium was ulcerated on the outer aspect of the mass and had mild hyperplastic changes focally where it was intact. A mild lymphocytic infiltrate was seen near the bass of the mass, and at the right medial corneal limbus. There was no gross or histologic evidence of pox virus infection in other organs. The left eye was not examined microscopically. Electron microscopy of formalin-fixed tissue from the corneal mass showed that the proliferative subepithelial cells contained many clusters of viral particles with a typical pox virus morphology.