Alterations in serum concentrations of CK, AST and LDH Arabian breed and Pantaneiro breed horses subjected to long duration effort (horse ride - "cavalgada") in Mato Grosso State - Brazil - Martins, E. A. N; Fernandes, Wilson Roberto; Ribas, José Antonio Silva; Germinaro, Ademir (Congress of the World Equine Veterinary Association, 2003)