Neoplasia in snakes at the National Zoological Park, Washington, DC (1978-1997)

Of 291 juvenile and adult snakes examined Post mortem over a 20-year period (1978-1997) at the National Zoological Park (NZP) in Washing-ton, DC, 36 ( 24 females and 12 males) had neoplasms. Two snakes had tumours of two or th ree different types, but the other 34 snakes had only one type. All affecte d animals were adults and their average time on exhibit at the NZP was 108. 9 months, Malignant neoplasms (79.5%) outnumbered benign neoplasms (20.5%). Of the malignant: tumours, 19 (61.3%) were considered to have arisen in me senchymal tissues, 11 (35.5%) were of epithelial origin, and one (3.2%) was derived from neuroectodermal tissues. All the benign neoplasms were of epi thelial origin. Neoplasms of the lymphoid and haematopoietic tissues were t he most common (12 cases), followed by tumours of the liver and biliary tra ct (seven cases) and the gastrointestinal tract (four cases). (C) 1999 W.B. Saunders Company Limited.