SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
albumin to globulin ratios in thoroughbreds typically being around 1.1 . Occasionally , a mild fall in total protein may be seen under the stress of progressively more intense training . Albumin concentrations , in particular , may be lowered in the first 2 months of training . This decrease , however , is transient . Acute changes in total protein concentrations are often observed following exercise . The most pronounced and enduring alterations have been associated with endurance races , mean increases of 25 % having been reported in horses following rides of 50 miles . Much of the increase is due to loss of body water in conjunction with heat dissipation . Protein concentrations , therefore , stay elevated unless the lost fluid has been replaced . In contrast , increases of up to 15 % have been noted following racing . These changes are short-lived and believed due to fluid shifts which cause temporary decreases in plasma volume .
PLASMA / SERUM BIOCHEMISTRY
Marked fluctuations in normal ranges of different plasma or serum constituents have been noted between individual horses . These variations may be compounded by differences between horses which could be attributed to differences in diet , sex , age , location , and level of fitness . The clinical value gained from the measurement of a large number of variables in samples obtained soon after the completion of exercise is probably limited . Rather , the practitioner may be better advised to wait until the horse has recovered from the work . This generally takes 3-6 hours , although in some endurance horses it may be longer . Exceptions to this suggestion obviously exist where the animal is suffering from an exercise-related malady and rapid assessment of its plasma biochemical status is indicated .
There is great variability in results of plasma electrolyte and enzyme concentrations following high speed workouts or racing , and those associated with submaximal exercise or endurance rides . The lack of consistent findings in many cases limits the interpretive value that can be placed on the results . In many cases this variability reflects differences in laboratory techniques , exercise conditions or the timing of blood sampling with respect to exercise .
MUSCLE ENZYMES
When interpreting the results of plasma CK and AST determinations , it is essential that they be related to the clinical appearance of the horse in question . It is well known that plasma concentrations of creatine kinase ( CK ), aspartate aminotransferase ( AST ), and lactate dehydrogenase ( LDH ) increase when muscle is damaged . Most attention have been given to CK and AST . Lactate dehydrogenase concentrations can increase in response to inflammation of many tissues , and as such , is less specific for skeletal muscle than the other two enzymes . Decreases in LDH have been noted in Thoroughbreds in response to training and with increasing age . The same study also found that resting values of LDH were higher in females than in geldings .
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