Incidence of Neoplasia in a Colony of Captive Felids at the Knoxville Zoological Park, 1979–2003
1Department of Veterinary Pathobiology, Purdue University, West Lafayette, IN, USA; 2Department of Small Animal Clinical Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN, USA; 3Department of Pathobiology, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN, USA
A review of medical records and necropsy reports found neoplasms in 27 zoo felids including 6 Panthera leo (3 males, 3 females), 3 Panthera pardus (2 males, 1 female), 1 Panthera onca (1 female), 11 Panthera tigris (3 males, 8 females), 2 Panthera uncia (1 male, 1 female), 2 Felis concolor (1 male, 1 female), 1 Felis rufus (1 male), and 1 Acinonyx jubatus (1 female). Neoplasia rate at necropsy was 43% (25/58), and overall rate of neoplasia in the collection was 21% (27/130). Neoplasia was identified as the cause of death or reason for euthanasia in 21% (12/58) of those necropsied. Neoplasms were observed in the endocrine (n=11), integumentary (n=11), reproductive (n=7), hematopoietic/lymphoreticular (n=5), digestive (n=2), hepatobiliary (n=2), and respiratory (n=1) systems. Multiple neoplasms were observed in 10 animals. Both benign and malignant neoplasms were observed in all systems except for the respiratory and hematopoietic/lymphoreticular systems where the process was benign in the former and malignant in the latter. Of the endocrine neoplasms, those involving the thyroid and parathyroid glands predominated (n=10) over other endocrine organs (n=1) and ranged from hyperplasia to carcinoma. In the digestive system, only the pancreas had neoplasms present. Both hepatobiliary tumors involved the biliary tree. In the integumentary system, 63% (7/11) of neoplasms involved the mammae with mammary carcinoma representing 83% (6/7) of neoplasms. The only respiratory tumor was a benign laryngeal papilloma. Hematopoietic/lymphoreticular tumors included lymphosarcoma (60%, 3/5) and mast cell tumor (40%, 2/5). Leiomyomas (60%, 3/5) and uterine adenocarcinomas (40%, 2/5) were observed in the female reproductive system, and seminomas were observed in the male reproductive system.