title: Urate nephrolithiasis in a northern elephant seal (Mirounga angustirostris) and a California sea lion (Zalophus californianus).
abstract: Nephrolithiasis has rarely been reported in marine mammals. During 2004 and 2005, two cases of nephrolithiasis were diagnosed during routine necropsy examination, one in a northern elephant seal (Mirounga angustirostris) and one in a California sea lion (Zalophus californianus). Nephroliths were found throughout both kidneys during necropsy examination, varying in size from 1-10 mm in diameter in the northern elephant seal and from 1-15 mm in diameter in the California sea lion. Necropsy and histopathology revealed nephroliths in association with renal pelvic dilation and pyelonephritis in both animals. In addition, hydronephrosis was noted in the sea lion. Nephroliths were composed of uric acid and ammonium urate in the northern elephant seal and of ammonium urate in the California sea lion. The underlying disease leading to nephrolith formation was not determined; however, it is hypothesized that unknown metabolic derangements due to morphologic or physiologic differences may have played a role. This is the first report of urate nephrolithiasis in the California sea lion and northern elephant seal.
authors.affiliation: The Marine Mammal Center, Marin Headlands, Sausalito, California 94965, USA.
authors.forename: Sophie
authors.initials: S
authors.lastname: Dennison
authors.forename: Frances
authors.initials: F
authors.lastname: Gulland
authors.forename: Martin
authors.initials: M
authors.lastname: Haulena
authors.forename: Helio
authors.initials: H
authors.lastname: De Morais
authors.forename: Kathleen
authors.initials: K
authors.lastname: Colegrove
mesh_terms: D000818:Animals; D002140:California / Q000453:epidemiology; D017809:Fatal Outcome; D005260:Female; D007668:Kidney / Q000473:pathology; D007669:Kidney Calculi / Q000737:chemistry / Q000662:veterinary*; D008297:Male; D053040:Nephrolithiasis / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D046070:Sea Lions; D046048:Seals, Earless; D014527:Uric Acid / Q000032:analysis
chemical_list: D000644:Quaternary Ammonium Compounds; D014527:Uric Acid