Fig. 1

Flow diagram of dogs with joint pain eligible for inclusion in the study. The diagnostic cut-off value for C-reactive protein (CRP) was 20 mg/l. Dogs were classified to have suppurative (supp) arthritis or osteoarthritis (OA) based on synovial fluid analysis (reference test); for classification as OA, signs of OA on radiographs/arthroscopy was further required. Dogs with inconclusive test results were excluded. ¹Pathological bleeding (n = 3) and non-diagnostic sample due to severe iatrogenic bleeding in synovial fluid sample (n = 2). ²No OA was diagnosed on radiographs/arthroscopy (n = 2)