Evaluation of cerebrospinal fluid lactate and plasma lactate concentrations in anesthetized dogs with and without intracranial disease.

The objectives of this study were to establish a reference interval for canine cerebrospinal fluid lactate (CSFL) and to compare CSFL and plasma lactate (PL) concentrations in anesthetized dogs with and without intracranial disease. Using a prospective study, canine blood and cerebrospinal fluid were collected for lactate analysis in 11 dogs with intracranial disease after undergoing magnetic resonance imaging (MRI) (Group ID-MRI), in 10 healthy dogs post-MRI (Group H-MRI), and in 39 healthy dogs after induction of anesthesia (Group H-Sx). Dogs were anesthetized for the procedures using different anesthetic protocols. Neurological scores (NS) and sedation scores (SS) were assessed pre-anesthesia in ID-MRI dogs. The CSFL reference interval [90% confidence interval (CI) for lower and upper limits] was 1.1 (1.0 to 1.2) to 2.0 (2.0 to 2.1) mmol/L. Mean ± SD CSFL concentrations were: ID-MRI, 2.1 ± 0.8; H-MRI, 1.6 ± 0.4; and H-Sx, 1.6 ± 0.2 mmol/L. There was a tendency for higher CSFL in dogs in the ID-MRI group than in those in the H-MRI or H-Sx groups (P = 0.12). There was agreement between CSFL and PL in ID-MRI dogs (P = 0.007), but not in dogs in H-MRI (P = 0.5) or H-Sx (P = 0.2). Of the ID-MRI dogs, those with worse NS had higher CSFL (r (2) = 0.44). The correlation between CSFL and PL in dogs with intracranial disease and between worse NS and higher CSFL warrants further investigation into the use of CSFL and PL for diagnostic and prognostic purposes.