Tolfenamic acid and meloxicam both provide an adequate degree of postoperative analgesia in dogs undergoing ovariohysterectomy

Abstract

This study was aimed at comparing the postoperative analgesic effects of tolfenamic acid and meloxicam in dogs undergoing ovariohysterectomy. Ovariohysterectomy was performed in 24 female dogs. All dogs were administered pre-anaesthetic medication comprised of 0.02 mg/kg i.m. acepromazine, and general anaesthesia was induced with i.v. propofol (4-6 mg/kg) and maintained with 1.5-2.0% isoflurane. Dogs were divided into three groups (n = 8). Following induction of anaesthesia, group C received 0.05 ml/kg sterile saline i.m.; group T received 4 mg/kg tolfenamic acid i.m.; group M received 0.2 mg/kg meloxicam s.c. Heart rate, respiratory rate, rectal temperature, mean arterial pressure and arterial oxygen saturation of haemoglobin were monitored intraoperatively. Pain was assessed using the short form of the Glasgow composite pain scale (SF-GCPS) by two observers who were blinded to the treatment groups; pain was assessed at the time of pre-medication (baseline), and at 2, 4, 6, 8, 12 and 24 h after extubation. Rescue analgesia (0.2 mg/kg i.m. methadone) was administered to any dog with an SF-GCPS score of greater than or equal to six during postoperative monitoring. The pain score in group C was significantly higher compared with group T and group M at 4, 6 and 8 h, while there were no significant differences between the two treatment groups. The mean pain score in group C was also higher than that in group M at 2 h. Rescue analgesia was first administered at 4 h in group C. Rescue analgesia was required by significantly more dogs in group C (n = 8) compared with groups T (n = 0) and M (n = 1), but there was no significant difference between the two treatment groups. Thus, tolfenamic acid and meloxicam provide adequate postoperative analgesia to similar degrees over 24 h in healthy dogs undergoing ovariohysterectomy.