Effects of intraperitoneal tramadol and flunixin on pain and stress indices following ovariohysterectomy in rabbits

Background: Effective postoperative pain management is essential for improving recovery and promoting animal welfare in veterinary surgery. Rabbits are highly sensitive to surgical stress, and limited information is available regarding the comparative efficacy of intraperitoneally administered analgesics following ovariohysterectomy. Methods: Fifteen healthy adult female New Zealand White rabbits weighing ۱۹۰۰-۲۵۰۰ g were randomly allocated into three groups (n = ۵/group): control, tramadol (۵ mg/kg, intraperitoneal), and flunixin meglumine (۱ mg/kg, intraperitoneal). Animals were housed individually under controlled environmental conditions after a one-week acclimatization period. Following ovariohysterectomy, heart rate, respiratory rate, and rectal temperature were recorded at ۰, ۲, and ۶ h postoperatively. Postoperative pain was assessed using the Rabbit Grimace Scale at ۰, ۱, ۳, ۶, ۱۲, and ۲۴ h. Serum cortisol and melatonin concentrations were measured using rabbit-specific ELISA kits, and serum glucose was analyzed using an automated biochemical analyzer. Data were analyzed using SPSS version ۲۶. The level of statistical significance was set at ۰.۰۵. Results: Postoperative stress was most pronounced during the second hour after surgery and was characterized by increased heart rate, respiratory rate, cortisol, and glucose concentrations, along with decreased melatonin levels. Both tramadol and flunixin significantly reduced physiological pain indices, such as heart and respiratory rates, compared with the control group (P-Value<۰.۰۰۱), while behavioral pain indices also decreased following treatment. Tramadol was more effective in attenuating early physiological stress responses, whereas flunixin provided more sustained control of behavioral pain during later postoperative time points. However, differences in some biochemical variables among treatment groups were not statistically significant. Conclusion: Intraperitoneal administration of tramadol and flunixin reduced postoperative pain- and stress-related responses following ovariohysterectomy in rabbits. Tramadol showed greater efficacy during the early postoperative phase, whereas flunixin provided longer-lasting behavioral analgesia. These findings suggest that both agents may be useful for postoperative pain management in rabbits, although further studies with larger sample sizes are required.

کلیدواژه ها:

Rabbits ، Tramadol ، Flunixin Meglumine ، Postoperative Pain ، Analgesia ، Ovariohysterectomy