Surgical impact of laparoscopic and laparotomic elective ovariectomy on inflammatory and oxidative stress biomarkers in anestrus dogs

Objective: To compare the systemic inflammatory and oxidative stress responses after elective ovariectomy via open surgery (OPEN) or laparoscopy (LAP) in anestrus bitches. Study design: Prospective, blinded, randomized clinical trial. Animals A total of 26 healthy bitches. Methods: A total of 26 healthy bitches in anestrus were randomly assigned to undergo either LAP or OPEN ovariectomy (n = 13 per group). Blood samples were collected at four timepoints (preoperative-Tpre, 2 h-T2, 24 h-T24, and 7 days postoperative-T7) for quantification of interleukin-6 (IL-6) and paraoxonase-1 (PON-1), biological antioxidant potential (BAP), and reactive oxygen metabolites (d-ROMs). Results: IL-6 levels were higher in the OPEN group at Tpre, T24 and T7, while the LAP group exhibited a transient peak at T2 with a return to baseline by T7. PON-1 levels decreased in both groups at T2 but remained lower in the LAP group at T24 and T7. d-ROM levels were higher in the OPEN group, with an increase through T7, whereas the LAP group showed only a transient peak at T24. BAP levels increased in the OPEN group, but not in the LAP group by T7. Conclusion: LAP ovariectomy induced a milder and more transient inflammatory and oxidative response compared to OPEN surgery in bitches, likely due to reduced surgical trauma. Clinical significance: This study included only animals in anestrus. This is the first application of both canine-specific biomarkers of inflammation and canine-validated biomarkers of oxidative stress to compare techniques of elective canine spaying. These findings suggest that minimally invasive ovariectomy attenuates inflammatory and oxidative stress responses compared to OPEN technique in dogs.