[Evaluation of decreased glucose levels in the cerebrospinal fluid of dogs]

The aim of the study was to evaluate the glucose ratio (glucose level in the cerebrospinal fluid [CSF]/blood glucose level) as a quickly available marker for detecting bacterial meningoencephalomyelitis (BM).Blood and CSF samples of 328 dogs were reviewed and evaluated retrospectively. Following the neurological diagnosis, the dogs were assigned to seven different groups: steroid-responsive meningitis-arteritis (SRMA), intervertebral disc disease (IVDD), neoplasia of the central nervous system (N), idiopathic epilepsy (IE), bacterial meningoencephalomyelitis (BM), meningoencephalomyelitis of other origin (ME) and healthy dogs.The median of the CSF-glucose level (mmol/l) and the median of the glucose ratio in the SRMA group displayed the lowest values and differed significantly from the CSF-glucose levels of dogs in the groups IVDD, N, IE and healthy dogs (CSF-glucose level: p0.01; glucose ratio: p0.05). In the BM group, both parameters did not differ significant- ly from other groups, but displayed similar low levels as in the SRMA group. There was a negative correlation between the CSF cell count and the CSF-glucose ratio (Spearman correlation coefficient -0.322, p=0.01, R²=0.108).The CSF-glucose concentration cannot be used as a distinct marker to differentiate BM from other inflammatory CNS-diseases, especially from SRMA usually accompanied by severe pleocytosis. Low CSF-glucose levels appear to be caused by elevated CSF cell counts rather than by bacterial metabolism.For a definitive diagnosis of bacterial meningoencephalomyelitis in dogs, the detection of microorganisms remains necessary.