RESUMEN
Ten healthy mixed bred Iranian horses with no clinical signs of locomotion problem were chosen from Animal Husbandry Unit of the School of Veterinary Medicine, Shiraz University. Synovial samples were taken from both fetlocks of the forelimbs without the use of tranquilizers or local anesthetics. Blood samples were also obtained from the jugular vein immediately following synovial samples. Clinical pathological examination of the samples revealed the following results: 1- Appearance was pale, yellow and clear with no debris. 2-No clot formation was observed at room temperature. 3- Mucin precipitation test was normal. 4- Mean and standard error values for the red and the white blood cell count were 4450 +/- 1173 and 152.5 +/- 29, respectively. 5- Differential counts were as follow: Lymphocytes [71.5% +/- 1.8], monocytes [23.1% +/- 1.5] and neutrophils [5.35% +/- 0.93]. 6- No significant difference was observed between synovial and serum glucose concentration which was measured simultaneously. 7- The amount of total protein of synovial fluid was 1.2 +/- 0.15 g/dl. 8- Comparative values of the synovial fluid of the left and right fetlock showed that there were no significant differences in leukocytes, neutrophils, protein and glucose but differences were observed in erythrocytes, lymphocytes and monocytes [p<0.05]. Comparing the findings of this study with investigations carried out by others, it was shown that in some parts, there are similarities and in others there are some variabilitis. This study was carried out on horses which were active in racing or heavy daily exercise. It has been shown that daily exercise can have some effects on the composition of the synovial fluid