Abstract

A 22-year-old male California sea lion (Zalophus californianus) developed a superficial epithelial central corneal ulcer on his right eye. The eye was treated with topical antibiotics and the ulcer improved, only to recur weeks-to-months later. Each time the corneal lesion returned, the defect was larger in diameter and the fluorescein stain migrated under the normal appearing epithelium. Fungal and bacterial cultures were performed on two occasions, with no growth. The eye was examined using a slit lamp biomicroscope, and the consensus was that the ulcer appeared to be most like a persistent non-healing ulcer similar to the indolent ulcers seen in dogs (often called "Boxer" ulcers). In canine patients, such surgical procedures as grid keratotomy or superficial keratectomy are often performed to address this condition. Because of the potential complications associated with administering general anesthesia to sea lions, we did not consider these techniques. In order to facilitate frequent corneal ulcer debridement, the sea lion was trained to open his eye on cue, and to allow debridement of the lesion by the trainer using a sterile cotton-tipped swab. Initially, this was accomplished using proparacaine 0.5 percent ophthalmic drops to locally anesthetize the cornea. The cornea was debrided once a week initially for several weeks. The ulcer showed marked improvement, and debridement was then limited to once every two to three weeks. At that point the animal allowed debridement of the ulcer without the use of the proparacaine. The ulcer healed after three months of treatment.