Mycobacterial keratitis in a parrot.

Histologic examination revealed acid-fast organisms in a granulomatous lesion involving the cornea of an eye of a Maximilian's Parrot. Disseminated mycobacteriosis was also diagnosed. Antemortem attempts at determining the cause of the corneal lesion had been unsuccessful. Ocular involvement in birds with avian tuberculosis is uncommon. The corneal lesion in the parrot was likely initiated by a dysfunctional third eyelid.