Erythrocyte Sedimentation Rates and Leukogram Changes in Canine Model of Osteoarthritis

Inflammatory markers such as erythrocyte sedimentation rates (ESR) have been evaluated in humans withosteoarthritis (OA). However, there has been no record of evaluation of ESR during OA in dogs. Changes in erythrocytesedimentation rates (ESR) and leukogram functions were evaluated following experimental knee osteoarthritis (OA).Tendogs of both sexes with (mean weight = 12.4 ± 1.8kg) were used. Experimental OA was induced in the right knee, using thegroove model and confirmed radiographically using evidence of joint space narrowing and presence of osteophytes. Gaitwas assessed subjectively and scores (GAS) were assigned. Blood was obtained fortnightly for the determination of ESR,total white blood cell (tWBC), neutrophil and lymphocyte counts, while knee radiographs were obtained fortnightly fortwelve weeks. Radiographic scores (RAS), GAS, ESR and leukocyte parameters between the different time points werecompared with ANOVA. Correlation between parameters was evaluated using Pearson's correlation. A "P" value less than0.05 was considered significant. Both ESR and neutrophil/lymphocyte (N/L) ratio increased from week 0 to week 12 of OA.However, tWBC, neutrophil and lymphocyte counts did not differ significantly. Both GAS and RAS increased up to week 4and 6 of OA respectively. Erythrocyte sedimentation rates was significantly (p= 0.033) and positively correlated (r=0.793)with N/L ratio, but negatively and slightly correlated (r= -0.843) with GAS. There was no significant correlation betweenESR and RAS. It was concluded that both ESR and N/L ratio might be useful in monitoring progression of OA in dogs.