Leptospirosis a zoonotic disease and has been identified in numerous domestic and nondomestic: animal species. Leptospira Pomona is one of the most common and important serotypes infecting wild and domestic animals in North America.

In 1984 the Marine Mammal Center (MMC) admitted 226 California seal lions (CSL) rescued from California beaches over a seven month period. The animals suffered from renal disease, leukocytosis, fever, anorexia and depression. Serologic analysis via microscopic agglutination and darkfield microscopy of kidney macerate led to a presumptive diagnosis of leptospirosis.

In 1991 from June through December MMC admitted 151 CSL's with clinical signs similar to those seen in 1984. To provide definitive diagnosis of leptospirosis infection, a study was conducted on these sea lions to isolate the organism via bacterial culture and correlate the identified pathogen with histopathology and immunology results.

To determine the prevalence of leptospirosis infection, kidney tissue of all pinniped species that were admitted to MMC and died within June - December 1991 were tested using fluorescent tagged polyvalent antibody.

Positive cultures were sent to National Veterinary Services Laboratory at Ames Iowa and identified as Leptospira pomona. The techniques employed in this study and results will be discussed.