Many reports implicate Staphylococcus aureus as the causative agent in mortalities of cetaceans. There were (3) such confirmed cases at Ocean Park, in 1976, 1984 and 1992. S. aureus is ubiquitous in Ocean Park, having been isolated from healthy cetaceans, pinnipeds, goats, rabbit eye, penguins, otters and the nares of trainers. The present report describes more recent clinical cases in our bottlenose dolphins due to S. aureus.

A young female bottlenose dolphin presented with clinical signs of inappetence, pyrexia and lethargy in March, 1991. On microbiological examination, a haemolytic S. aureus was cultured and ultrasonographic examination revealed an area of consolidation in the caudoventral aspect of her left lung. This lesion was confirmed by radiography. Treatment with appropriate antibiotics resulted in regression of clinical signs. In January, 1994, lethargy, pyrexia and inappetence again were apparent with isolation of a non-haemolytic S. aureus. Ultrasonographic examination determined evidence of a new pulmonary lesion adjacent and medial to the pneumonic lesions from the March, 1991 episode. Treatment was instituted and is continuing. Haematological and biochemical values were monitored throughout the two clinical courses and on a regular basis. During both episodes, other bottlenose dolphins housed in close proximity to the clinical case also yielded S. aureus.

The isolates from cetaceans and trainers will be compared by phage typing and antibiograms. In addition, antibodies specific to S. aureus were determined in the cetaceans and an experimental autogenous vaccine undergoing tests at Ocean Park, will be discussed.