A retrospective study of neoplasia in a collection of snakes was condu
cted due to the large number of neoplasms observed in 1991. Individual
snake necropsies, medical records, and inventory records at the Sacra
mento Zoo were reviewed for the period 1 July 1981-30 June 1991. Twent
y-nine neoplasms were diagnosed in 20 individual snakes. Nineteen neop
lasms were of epithelial origin, and 10 were of mesenchymal origin. Tw
enty-two (76%) neoplasms were considered malignant, and five neoplasms
had metastases. Seven of 10 mesenchymal neoplasms were poorly differe
ntiated spindle cell sarcomas. Five snakes had multiple types of neopl
asms. Thirteen neoplasms were detected clinically and diagnosed antemo
rtem. The annual rate of neoplasia for the population ranged from 0% t
o 14.1% and increased dramatically from 1988 to 1991. No specific type
of neoplasm was more prevalent during this increase. The annual rate
of neoplasia at necropsy ranged from 0% to 70% and was 23.1% for the 1
0-yr study period.