Alkaptonuria in a cynomolgus monkey (Macaca fascicularis).

An eight year old wild caught Cynomolgus monkey was diagnosed as having alkaptonuria, a condition characterized by the passage of a normal-colored urine which darkens upon standing. The underlying cause is the congenital lack of homogentisic acid oxidase with subsequent passage of homogentisic acid in the urine. No other clinical manifestations, such as deposition of pigment in the skin or mucous membranes or development of an ochronitic arthritis, were observed in this animal.