In April 1990, a 400 pound, 17 year old, castrated male sea lion presented with a purulent and slightly hemorrhagic right sided nasal and auricular discharge. A 6 cm diameter swelling was apparent caudo-ventral to his right pinna. The animal was moved into an isolation facility and, over a period of two months, was placed on several antibiotics, including Doxycycline, Amoxicillin, and Keflex. On June 4th the swelling and discharge had subsided for over 10 days and antibiotic therapy was discontinued. On July 7th the swelling recurred and the sea lion became anorexic and lethargic. Antibiotic therapy began on July 9th with Naxcel (ceftiofur sodium), 300 mg IM twice a day. Since non-invasive treatment methods appeared unsuccessful, he was scheduled for surgery.

On July 12th, the animal was premeditated with 1.2 mg glycopyrrolate (Robinul-V) IM. Fifteen minutes later, 350 mg of Telazol was injected IM. Both injections were given using a blow dart hypodermic and aimed at the gluteal and triceps muscles. After 10 minutes the animal was tractable. He was masked down with 5% Isoflurane, intubated with an 18 mm endotracheal tube, and maintained for approximately one and one half hours at 2-5% Isoflurane. Temperature, respiratory rate, and heart rate were monitored throughout the procedure and ranged as follows:

The animal was placed on 100% oxygen for 10 minutes prior to disconnection from the anesthetic machine. Twenty minutes later the animal was extubated and his recovery was smooth and uneventful.

The surgical procedure itself was divided into two phases. The first consisted of an oral exploratory examination and dental prophylaxis. There was no evidence of the swelling within the pharyngeal region, no foreign objects were noted, and the mucosa appeared normal and unbroken. Severe periodontal disease was present around many of the incisors and premolars, leading to the extraction of these teeth. However, nothing was found which could be correlated with the periauricular swelling.

The second phase of the surgery focused on the swelling itself. Pre-surgical radiographs were taken using a portable Bowie unit in hopes of evaluating cervical vertebrae 1 and 2 as well as the area of the tympanic bulla. However, the films were of limited diagnostic value as it appeared our radiographic technique was not well suited for the portable unit. As the surgery site was prepared, the skin over the area showed numerous scars, possibly due to interactions with other animals, and perhaps the original source of tissue injury. Prior to incision, a fine needle aspirate revealed the mass's contents to be purulent. The abscess yielded pure cultures of E. coli and Group D Enterococcus. Underlying musculature and auricular cartilages did not appear affected.

Post operative care involved restricting the animal's access to a pool while providing him with overhead water spray. The wound was flushed 4-5 times a day with dilute Nolvasan. Sensitivity tests indicated both organisms were sensitive to Doxycycline, so the sea lion was placed on 500 mg Doxycycline once a day. Antibiotic therapy was discontinued after two months.

Unfortunately the swelling has recurred twice since the surgery. Each time the abscess drained through the original surgical incision. Doxycycline was administered until one week after the reduction of the swelling. The case is ongoing. We are waiting to see if a more thorough surgical exploration of the area is necessary.