Abstract
Equine exertional rhabdomyolysis (ER) is a well-recognized disease affecting racehorses therefore this study was performed to evaluate haemato-biochemical alterations in 20 adult Arabian horses after 120 km race with trial of treatment. Horses were classified into 2 main groups: the first group (n:5) included healthy control horses while the second group(n:15) included horses showed signs of distress, moderately depressed, muscle stiffness, shifting hind limb lameness, elevated respiratory rate, sweating, firm painful hindquarter muscles, myoglobinuria and reluctance to move that lasts for several hours after ending of race. Based on the history and the through clinical examination of diseased horses, they were tentatively diagnosed as suffering from ER syndrome. Whole blood and serum samples were collected from both healthy control horses and diseased ones before and after treatment. Hemogram of examined horses showed only significant increased PCV (%) values of diseased horses with more prominent thrombocytopenia but with treatment their values showed marked improvement, where other haematological parameters showed non-significant changes in both groups either before or after treatment. Serum analysis of ER affected horses showed a higher serum enzymatic activities of creatine phosphokinase (CK) and aspartate aminotransferase (AST) with significantly increased values of total proteins, albumin, globulins, total bilirubin, glucose, creatinine and potassium. But with effective treatment protocol, these higher values began to be improved towards normal values again. While non-significant changes were observed in serum levels of Gamma-glutamyl transpeptidase (GGT), calcium, sodium and blood urea nitrogen (BUN) in ER affected horses. Based on obtained results, ER has negative impact on haemato-biochemical biomarkers with remarkable serum elevation of skeletal muscular specific enzymes, as well as by paralytic myoglobinuria.

Key words: Exercise related myopathy, Endurance horses, Exertional rhabdomyolysis