In most animals, pain can compromise physiological functions and delay healing so, rapid detection of pain through behavior and inflammatory reaction with biomarkers are necessary. This study aimed to evaluate pain, physiological variations and Acute Phase Proteins (APP) in donkeys undergoing orchiectomy technique by inguinal access. For this research, 15 male northeastern donkeys kept in extensive management were selected, with a mean age of 4.5±3.1 years. All animals had the same anesthetic protocol, using dissociative anesthesia and local block with lidocaine, followed by orchiectomy by inguinal access. Due to their predisposition to complications, the inguinal technique is the most indicated to minimize complications and excessive inflammation in donkeys' orchiectomy, the donkeys were evaluated regarding behavioral assessment of pain, hematological parameters, APP and the surgical wound, during 0h, 24h, 48h and 72h. As for the physiological parameters and APP, no significant differences were observed between times, due to the use of non-steroidal anti-inflammatory drugs. In the macroscopic evaluation of the surgical wound, it was observed that there were no significant differences between the times, with animals presenting mean scores of 1.8±0.414, in 48 hours 1.6±0.507, and in 72 hours 1.6±0.507. Most animals had mild to moderate edema in the scrotum and foreskin regions. As for pain assessment, the average scores were between 2-3, representing mild and moderate pain, not requiring intervention. However, further research is needed to elucidate the behavior of PFAs in the face of variables and the creation of new pain scales for animals raised in an extensive system.