A 10-year-old male California sea lion (Zalophus californianus) presented for removal of numerous small stones that had accumulated in the stomach. Two procedures were performed under anesthesia to remove the stones. The first used restaurant-grade plastic tubing (4.8/3.5 cm external/internal diameter, 185 cm long), within which a smaller tube (0.9/0.6 cm, 190 cm long) was placed, exiting through a hole made in the side of the larger tube. This tube combination was placed per os into the stomach. The small tubing was attached to a faucet and the larger tubing to a commercial wet/dry vacuum. Water was delivered continuously through the small tubing while suction was applied using the vacuum. The animal was placed in dorsal, ventral, and lateral recumbency, and was tipped head-down, but only a few stones were retrieved. For the second procedure, a similar technique was performed using a larger gauge tubing (6.3/5.1 cm external/internal diameter, 193 cm long) and a larger tube for water delivery (1.9/1.3 cm diameters). In addition, the animal was placed on a custom-built table-top that could be tilted across a fulcrum approximately 60° in either direction. The animal was tilted tail-down, the stomach filled with water and the suction applied. While keeping the suction applied and water flowing, the animal was tilted into a head-down position to allow the stones to roll out of the tube into the vacuum. This process was repeated until no further stones were removed. This novel technique may be adapted for future attempts at gastric foreign body removal in large pinnipeds.
Special thanks to the Mammal Department at the Bronx Zoo for assistance with these procedures and for construction of the tilt table.