The creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) seric activities in horses of different activity classes (athlete, traction, and reproduction), were compared. Fifty-eight horses were alloted into three groups - group 1 with 20 athletes, "vaquejada" competitors; group 2 with 20 breeding horses; and group 3 with 18 draft horses, averaging 10 working hours daily. The average values for CK serum activity were 80.2, 83.9, and 94.4 U/l in groups 1, 2, and 3, respectively. Result of group 3 was significantly different from the other groups. The averages values for LDH were 102.5, 98.6, and 112.8 U/l in groups 1, 2, and 3, respectively, with no statistical difference between groups. The AST averages were 56.8, 33.0, and 50.1 U/l in groups 1, 2, and 3, respectively, with group 2 significantly differing from the others. Clinical biochemistry values of muscular function in horses varied according to activity category.
equine; muscular function; creatine kinase; lactate dehydrogenase; aspartate aminotransferase
