Use of Homeopathic Arnica montana 30cH for Postoperative Analgesia in Female Dogs Undergoing Elective Ovariohysterectomy

Background Ovariohysterectomy (OH) is one of the most frequent elective surgical procedures in routine veterinary practice. Arnica montana is a well-known medicine in phytotherapy, with proven analgesic, anti-inflammatory, antiseptic, healing, antioxidant and immunomodulatory activity. However, there is still a shortage of studies on the action and effects of the homeopathic formulation of the medicine on animals. The aim of this study was to evaluate analgesia with Arnica montana 30cH during the postoperative period after elective OH. Methods Thirty healthy female dogs, aged 1 to 3 years, weighing 7 to 14kg, were selected at the Veterinary Hospital in Campo MourAo, Parana, Brazil. The dogs underwent the surgical procedure with an anaesthetic protocol and analgesia that had the aim of maintaining the patient's wellbeing. After the procedure, they were randomly divided into three groups of 10. One group received Arnica montana 30cH; another received 5% hydroalcoholic solution; and the third group, 0.9% NaCl saline solution. All animals received four drops of the respective solution sublingually and under blinded conditions, every 10minutes for 1hour, after the inhalational anaesthetic had been withdrawn. The Glasgow Composite Measure Pain Scale was used to analyse the effect of therapy. Analysis of variance (ANOVA) followed by the Tukey test was used to evaluate the test data. Statistical differences were deemed significant when p <= 0.05. Results The Arnica montana 30cH group maintained analgesia on average for 17.83.6hours, whilst the hydroalcoholic solution group did so for 5.1 +/- 1.2hours and the saline solution group for 4.1 +/- 0.9hours ( p <= 0.05). Conclusion These data demonstrate that Arnica montana 30cH presented a more significant analgesic effect than the control groups, thus indicating its potential for postoperative analgesia in dogs undergoing OH.