Hematology and chemistry reference values for free-ranging harbor seals (Phoca vitulina) and the effects of hemolysis on chemistry values of captive harbor seals

Mast reported laboratory reference values for harbor seals (Phoca vitulina) are derived from captive seals, or stranded seals that have recovered from disease in marine mammal centers. This study established hematology and se rum chemistry reference values for free-ranging harbor seals, using methods and that are current and readily available, and determined the effects of hemolysis on serum chemistry values of captive harbor seals. Blood samples were collected for hematologic and serum chemistry measurements from 14 cli nically normal, adult male and female harbor seals and two juvenile harbor seals (approximate age 6 mo) captured in saltwater sloughs and estuaries ne ar Moss Landing, California, USA. Values for amylase, globulin, and differe ntial leukocyte count, not previously reported, were determined. In general , hematology and chemistry values in adults were similar to those reported for free-ranging and captive harbor seals, except for glucose, urea nitroge n, and lactate dehydrogenase (LDH) values, which were higher than those rep orted previously. Red blood cell counts in the two juveniles were higher th an in adults and in young harbor seals studied previously. To determine the effects of hemolysis on serum chemistry values, two intensities of hemolys is were generated experimentally in blood collected from 11 harbor seals re covering from injuries or stranding at the Marine Mammal Center (Sausalito, California 94965, USA). Moderate hemolysis (++, 1 g/L hemoglobin, red-ting ed) significantly increased LDH activity, whereas severe hemolysis (+++, 2 g/L hemoglobin, cherry red) significantly increased total protein, albumin, calculated globulin, LDH, and total bilirubin and significantly decreased creatinine. The effects of hemolysis must be considered when chemistry resu lts of harbor seals are interpreted.