In this study, 24 male New Zealand White rabbits aged 8 months-3 years, weighing 2.5-5.5 kg, were used to examine the effectiveness of different analgesics before orchiectomy surgery. The rabbits were divided into four groups: while the control group was not given an analgesic substance, the other groups were administered meloxicam, ketoprofen and buprenorphine analgesics intramuscularly, respectively. Ten minutes after analgesic administration, all rabbits were anesthetized with medetomidine-ketamine combination. In the study, parameters such as heart rate, respiratory frequency, body temperature, SpO2 and pain scoring was performed. Additionally, serum cortisol levels were evaluated with blood samples taken preoperatively, after anesthesia, at the end of orchiectomy, and at the 2nd, 4th and 6th hours postoperatively. The results showed that analgesic administration had significant effects on cortisol levels. Respiratory frequency did not show any significant change between the groups at each time point, however, in rabbits administered meloxicam, the preoperative measurements were significantly lower (p=0.008) compared to the intraoperative period. In rabbits administered buprenorphine, intraoperative and postoperative measurements were found to differ significantly from the preoperative measurements at (p=0.020) and (p=0.015) levels, respectively. An average decrease of 0.5°C in body temperature was observed in the meloxicam and buprenorphine groups, and anesthesia-related changes in heart and respiratory frequencies were observed. According to the level of serum cortisol, which is an acute biomarker of pain and pain response, it was concluded that the analgesic agent with the strongest analgesic effect was buprenorphine and the analgesic agent with the weakest analgesic effect was ketoprofen in the doses and administration routes specified in the study during orchiectomy operations in rabbits.