Acetic acid and 3-hydroxybutyric acid levels in cerebrospinal fluid of cattle

To evaluate the importance of acetic acid and 3-hydroxybutyric acid (3-HB) in cerebrospinal fluid (CSF) of cattle, CSF samples were taken from a population of 60 cattle including healthy and sick animals with central nervous disorders. Mean acetic acid and 3-HB levels in blood plasma were 0.30 (SD 0.24) and 0.30 (SD 0.28) mM, and those in CSF were 0.14 (SD 0.06) and 0.08 (SD 0.07) mM, respectively. Significant differences were observed between plasma and CSF samples for both acetic acid and 3-HB levels. Acetic acid levels in CSF showed less relationship with those in blood plasma, whereas plasma 3-HB levels accompanied proportional changes with its CSF levels, which were about 30% of plasma 3-HB. It was revealed that both acetic acid and 3-HB levels in plasma and CSF have less relationship to glucose levels in plasma and CSF; therefore, the decrease of glucose levels in plasma or CSF is not necessarily accompanied by hyperketonemia.