Description: Changes in leukocyte parameters, erythrocyte sedimentation rate (ESR) and interleukin-6 (IL-6) were determined in ten mongrel dogs following knee arthrotomy. About 5 mL of blood was collected from each dog before knee arthrotomy, 2 hours, 24 hours and 3 days after knee arthrotomy for determination of white blood cell counts (WBC), neutrophil counts (NEUT), lymphocyte counts (LYM), neutrophil-lymphocyte ratio (N/L), ESR and IL-6. The data were expressed as mean +- standard deviation and differences compared using analysis of variance (ANOVA) at level of significance P<0.05. The results of this study showed that following knee arthrotomy, WBC, NEUT and ESR were significantly (P<0.05) increased 24 hours after surgery, while there were no significant change in LYM and N/L. Increase in ESR persisted up to three days following arthrotomy. In addition, IL-6 was significantly (P<0.05) increased two hours after knee arthrotomy up to 24 hours after arthrotomy and then decreased significantly by the 3rd day. It was concluded that acute inflammation following knee surgery in dogs induced changes in leukocyte parameters, ESR and IL-6. These changes can be used to monitor prognosis following knee surgery in dogs