Composition of cerebrospinal fluid in clinically normal adult ferrets

Abstract Objective—To determine the protein and cellular composition of CSF in healthy adult ferrets. Animals—42 clinically normal adult ferrets. Procedure—CSF samples were collected from the cerebellomedullary cistern of anesthetized ferrets by use of disposable 25-gauge, 1.6-cm-long hypodermic needles. Samples were processed within 20 minutes after collection. The number of WBCs and RBCs per microliter of CSF was counted by use of a hemacytometer. The total protein concentration was determined by use of an automated chemistry analyzer. Results—Total WBC counts (range, 0 to 8 cells/µL; mean, 1.59 cells/µL) in CSF of ferrets were similar to reference range values obtained for CSF from other species. Twenty-seven CSF samples had < 100 RBCs/µL (mean, 20.3 RBCs/µL). A small but significant effect of blood contamination on WBC counts was found between the 27 CSF samples with < 100 RBCs/µL and the remaining samples. Protein concentrations in CSF of ferrets (range, 28.0 to 68.0 mg/dL; mean, 31.4 mg/dL) were higher than has been reported for the CSF of dogs and cats. A significant effect of blood contamination on the CSF protein concentration was not found. Conclusions and Clinical Relevance— We have established reference range values for WBC counts and protein concentrations in CSF from healthy adult ferrets that may be useful in the clinical investigation of CNS disease. Results of our study indicate that the WBC count is significantly affected by blood contamination of the CSF sample. (Am J Vet Res 2004;65:758–760)