Comparison of clinical chemical variables in blood plasma and serum of horses.

Several clinical chemical blood variables were compared, in order to evaluate the differences between Na heparinized plasma and serum samples. Samples from 45 healthy horses were used. No differences between the two sample substrates were found for aspartate aminotransferase, lactate dehydrogenase, lactate dehydrogenase-isoenzymes, creatine kinase, alkaline phosphatase, bilirubin, cholesterol, urea, total protein, alpha-globulin, gamma-globulin, albumin, calcium (Ca), phosphate (P), sodium (Na) and potassium (K). gamma-Glutamyltransferase and beta-globulin were significantly higher in heparinized plasma than in serum (each p less than 0.05) while magnesium (Mg) was lower (p less than 0.05). From the horse group used for the study, thoroughbreds in racing condition had significantly higher aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, bilirubin, P and Mg as well as lower Ca and K values than riding horses, irrespective of the sample substrate used. It was concluded that expect for gamma-glutamyltransferase, beta-globulin and Mg, there was no significant difference between the clinical chemical variables of Na heparinized plasma and serum samples.