METASTATIC CARCINOMA OF PROBABLE TRANSITIONAL-CELL ORIGIN IN 66 FREE-LIVING CALIFORNIA SEA LIONS (ZALOPHUS-CALIFORNIANUS), 1979 TO 1994

Sixty-six (18%) cases of widely metastatic carcinoma of probable trans itional cell origin were identified in 370 California sea lions (Zalop hus californianus) stranded alive along the central California (USA) c oast, between January 1979 and December 1994. Live animals were usuall y emaciated and anorectic, with perineal edema and occasionally hind-f lipper paralysis or paresis. Large yellow caseous masses were observed in the sub-lumbar lymph nodes, often extending around the ureters res ulting in hydroureter. Histologically, metastases were usually widespr ead, and the primary neoplastic focus undetectable. This is the highes t reported prevalence among necropsied animals of neoplasia in a pinni ped population to date.