Survey of neoplasia in red kangaroos (Macropus rufus), 1992-2002, in a zoological collection.

An increase in the proportion of cases with neoplasia observed in a collection of captive red kangaroos (Macropus rufus) when compared with historical records and the paucity of reported neoplasms in kangaroos in the literature prompted a 10-yr review of all red kangaroo necropsies. Individual necropsy, medical, and inventory records for all kangaroos at the Kansas City Zoo were reviewed for the period 1 January 1992 to 31 December 2002. Two squamous cell carcinomas of the oral cavity, two mammary gland adenocarcinomas, a multicentric T-cell lymphosarcoma, and one submucosal pyloric lipoma were diagnosed in six of 28 kangaroo deaths. Three neoplasms were diagnosed antemortem. Four of the six neoplasms were considered malignant, and all four had metastasized. The mean age at death was 11 yr. All six animals with neoplasms were female; however, the exhibit population was composed solely of females. Only 11 cases of neoplasia in red kangaroos have been reported in the literature. On the basis of these cases and a review of the literature, the most commonly observed neoplasms in red kangaroos are mammary gland adenocarcinomas and oral squamous cell carcinomas. Common denominators were not identified in these cases, although chronic gingivitis could have been a contributing factor in the development of the oral squamous cell carcinomas.