Summary
Objective: To report synovial fluid lactate concentrations in normal and pathological canine
joints.
Study design: Controlled, prospective study.
Methods: Lactate was measured in synovial fluid using a hand-held meter and the rest of the
fluid was sent to a commercial laboratory for analysis. Samples were divided into
four groups; group 1: control, group 2: osteoarthritis, group 3: immune-mediated inflammatory
arthritis, and group 4: septic arthritis. Statistical analysis was performed to compare
lactate concentrations between the four groups and to examine the predictive value
of lactate in the diagnosis of septic arthritis. A correlation was sought between
synovial fluid lactate and synovial fluid total nucleated cell count and total protein.
Results: Seventy-four samples were investigated from 55 dogs. Statistical analysis found that
lactate concentrations were significantly higher in the septic arthritis group than
in each of the other three groups. No significant correlation could be found between
synovial fluid lactate concentrations and synovial fluid total nucleated cell count
or synovial fluid total protein. Lactate concentration was found to be a useful predictor
of septic arthritis, with a low concentration pointing towards exclusion rather than
a high concentration to the diagnosis of septic arthritis.
Clinical significance: Synovial fluid lactate concentration is not a good marker for osteoarthritis or immune-mediated
inflammatory arthritis, but it is significantly increased in septic arthritis and
could help the clinician in ruling out this condition in a quick and cost-effective
way.
Keywords
Canine - synovial - lactate - arthritis - septic
