Staff at the Ramat Gan Safari conducted tumor-removal surgery on Samouni, an eight year-old African lion on Wednesday, in a special operation caught on film.
The lion's trainers noticed swelling in Samouni's abdomen recently and was diagnosed after an emergency biopsy.
Safari animal veterinarian Dr. Yigal Horowitz performed the two-hour operation, and the lion is expected to be up and back on his feet by Thursday.
In the meantime, the tennis-ball-sized tumor is being analyzed to determine whether it is benign or malignant - a diagnosis that could have great ramifications for the leader of the pack.