Postoperative pain in dogs undergoing either laparoscopic or open ovariectomy

A prospective, quasi-experimental, clinical trial was performed to assess acute postoperative pain in healthy female dogs following elective ovariectomy by either laparoscopy (n=13) or laparotomy (n=14). Pain was assessed by both a veterinarian at the hospital, and by the owner once the patient was discharged. The Spanish version of the short form of the Glasgow Composite Measuring Pain Scale (CMPS-SF) was used. Pain scores were assessed by the veterinarian preoperatively and at 1, 2, 4, and 6 h after extubation, whilst owner-assessed scores were performed preoperatively and at postoperative days 0, 1, 2, 3, 5 and 7. Data were compared with Mann-Whitney-U test. Veterinarian-assessed CMPS-SF scores were different between both groups at all postoperative times but not at baseline, being below 6/24 in all dogs in the laparoscopy group, but equal to or greater than 6/24 in the laparotomy group at 1 h (n=12), and 4 h (n=4) (P<0.001 and P=0.029, respectively). There were also differences in pain scores between both groups at 2 h (P=0.012) and 6 h (P=0.007), being below 6/24 in all of them. However, there were no differences in owner assessments between groups. In conclusion, ovariectomy performed by laparoscopy induced lower pain scores that were below the pain threshold set by the CMPS-SF during the first 6 h postoperatively. After discharge, and up to one week later, ongoing owner-assessed scores suggest no pain was induced with neither of the techniques. Owners were proactive allowing real-time pain assessment to be reported. The development and validation of instruments for acute pain assessment by owners is warranted, as these tools are currently lacking.