Diagnostic value of cerebrospinal fluid analysis in a population of dogs with suspected idiopathic epilepsy.

Cerebrospinal fluid (CSF) analysis is commonly used in the diagnostic investigation of seizure disorders in order to exclude possible inflammatory underlying aetiology. The medical records were searched for dogs presenting with epileptic seizures (ES) that had normal interictal neurological examination, normal complete blood count and biochemistry analysis, unremarkable MRI of the brain and had CSF analysis performed as part of the diagnostic investigation. A total of 200 dogs met the inclusion criteria. The CSF was abnormal in 30 dogs with a median total nucleated cell count of two cells/µl (IQR 1.5-6) and median protein concentration of 0.37 g/l (IQR 0.31-0.41). Pleocytosis was recorded in 14/30 dogs and the CSF protein was increased in 22/30. There was no correlation between abnormal CSF and the type or number of seizures or the time interval between the last seizure and CSF collection. A significant correlation was found between the number of red blood cells on CSF and having an abnormal CSF. The prevalence of having a diagnosis other than suspected idiopathic epilepsy (IE) was 0.5 per cent (1/200). These results suggest that performing CSF analysis in dogs with recurrent ES that have normal interictal neurological examination and unremarkable MRI has a low diagnostic value.