Reference intervals for feline cerebrospinal fluid: biochemical and serologic variables, IgG concentration, and electrophoretic fractionation.

Reference intervals are reported for feline CSF biochemical and serologic variables, IgG concentration, and electrophoretic fractionation, derived from 58 clinically normal adult cats that did not have histologic lesions of the CNS. There was no apparent effect of age on any variable. The CSF total protein concentration was significantly (P = 0.012) greater in males than in females, but all other variables were unaffected by gender. The only variable that had a statistically significant correlation with its corresponding blood concentration was IgG. Blood contamination of the CSF affected the following CSF variables: total protein concentration, activities of lactate dehydrogenase and creatine kinase, IgG ratio, and gamma-globulin percentage. The reference intervals proposed for feline CSF were derived from 33 cats with CSF RBC count less than 31 cells/microliters. Reference limits for CSF with 31 to 1,700 RBC/microliters also are reported.