Background and Aim: Ovariohysterectomy (OHE) is a common procedure for sterilization of female dogs. However, knowledge of changes in pain stress, oxidative stress, and total antioxidant power status before, during, and after OHE is limited. The objective of this experiment was to study the effect of duration on pain stress, oxidative stress, and total antioxidant power status in female dogs undergoing OHE.

Materials and Methods: Seven female dogs were sterilized using the OHE method. Pain scores, hematological changes, and biochemical markers were investigated during pre-operative, 3 h after starting OHE, and on days 3, 7, 10, and 14 of an experimental period. Data were analyzed using one-way analysis of variance.

Results: At 3 days after OHE, pain score was higher than on days 7-14 of the experimental period; percentage of neutrophil, 3 h after starting OHE, was higher than during pre-operative and on days 3-14 of the experimental period; percentage of lymphocyte on days 10-14 was lower than during pre-operative, 3 h after starting OHE, and on days 3-7 of the experimental period; neutrophil/lymphocyte ratio, 3 h after starting OHE, was higher than during pre-operative and on days 3-14 of the experimental period; plasma malondialdehyde on day 3 was higher than during pre-operative, 3 h after starting OHE, and on days 3-14 of the experimental period; and total antioxidant power on day 14 was higher than during pre-operative, 3 h after starting OHE, and on days 3-10 of the experimental period, respectively.

Conclusion: This experiment indicated that OHE caused pain stress, oxidative stress, and reduction of total antioxidant power in female dogs. Finally, female dogs needed antioxidant for 7 days after OHE.

Keywords: female dog, ovariohysterectomy, oxidative stress, pain stress, total antioxidant power.