This study investigated the effects of postoperative pain following soft and hard tissue operations in dogs on Adrenocorticotrophic Hormone (ACTH) levels, dopamine levels, haemocoel values and blood gases. It also evaluated the results of the applied treatments. The study was carried out in 4 groups each comprising 6 dogs. Dogs in the 1st and 3rd groups underwent laparotomy and those in the 2nd and 4th groups underwent osteotomy. Carprofen (4.4 mg kg-1) (Rimadyl, Pfizer) was administered subcutaneously as an analgesic to the dogs in the 1st and 2nd groups following the operation. Venous blood samples were collected from the animals before the operation and in the subsequent hours to determine the ACTH and dopamine levels. In the postoperative period, ACTH and dopamine levels were significantly higher in the groups that underwent osteotomy than in the groups that underwent laparotomy (p<0.05). Statistically significant decreases were observed in the groups that received analgesia after the 2nd h (p<0.05). In this study, effective postoperative analgesia is required after both soft and hard tissue operations. Furthermore, effective and rapid implementation of the process is important for postoperative animal welfare and rapid return to normal physiological functions.