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Objective: Evaluation of exercise tolerance of horses in the rest and post-exercise by measurement of changes inhematological factors and enzyme activities.
Design: Comparative study.
Animals: Nineteen Iranian cross-bred race horses aged 5 to 14 years old and 350 to 450 Kg weight.
Procedure: Two blood samples were taken at rest and after galloping in 1 mile track .Auscultation of heart was done at rest and immediately after exercise up to 60 minutes.Blood samples were submitted to laboratory for hematological and biochemical experiments. The commercial kits were used to measurement of enzyme activities.
Statistical analysis: T-student test, Analysis of variance, SPSS program.
Results: The mean of PCV,RBC values and, CPK, AST, and LDH activities at rest were obtained, 36.60 +_ 3.3
percent,6.8+_0.88 million/ul,196.8+_20.3u/l, 233.78 +_29.73 u/l and 327.05+_58.25 u/l respectively. The mean values of these factors after exercise were significantly increased to before exercise (p<0.05). The mean of resting heart rate was 36.10+_5.S4 bpm and the mean of maximum heart rate and heart rate in sixtinth minutes after exercise were 131.89+_16.83 and 42.36+_11.70 bpm respectively, there is significant increase of maximum heart rate to resting heart rate (p<0.05).
Clinical implications: Although there is significant increase in enzyme activities, but marked and pathological increase do not occur and therefore there is no any evidence of muscular/cardiac damage or poor performance. There are rather good capacity of PCV and cardiac reserve in the horses with regard of sub maximal
exercise. Measurement of serum enzymes alone, are not reliable for detection of poor performance. However, detection of such factors in the precence of acute damage or along with some other factors like PCV and HR are valuble for determination of poor performance. J.Fac. Vet.Med. Univ. Tehran. 60,2: 195 - 199,2005