The aim of this study was to evaluate and to compare the possible inflammatory changes by screening acute phase proteins concentrations in healthy bitches subjected to ovariohysterectomy. Minimally invasive and conventional (laparotomy) ovariohysterectomies were performed in 17 client-owned adult female mixed breed dogs. Nine animals were subjected to minimally invasive and eight animals to conventional ovariohysterectomy. Blood samples were taken before surgery, 24, 48 hours, and seven days postoperatively. Serum C-reactive concentration was determined by a commercial ELISA kit and serum haptoglobin concentration was measured via hemoglobin binding assay, both previously validated for use in dogs. As the data did not meet the normal distribution criteria, the nonparametric Kruskall-Wallis was performed to compare quantitative variables between groups. One-way ANOVA and the Friedman test were used for multiple comparisons between time points, with a P<0.05 considered significant. C-reactive protein concentration was significantly different (P<0.0001) at 24 hours postoperatively between groups. There was no significant difference in haptoglobin concentration between groups. C-reactive protein and haptoglobin concentrations were significantly different at 24 and 48 hours postoperatively for minimally invasive and conventional ovariohisterectomies. These findings provided an overview of the short-term inflammatory effects produced by minimally invasive and conventional ovariohysterectomies.