Simple SummaryIn livestock animals, such as goats, many routine management procedures in production systems, e.g., castration and dehorning, are painful, and most are performed without proper anesthetic or analgesic protocols for pain management. Validated pain assessment scales are important to detect pain and indicate painkillers to improve the welfare of these animals. Goats are one of the few production animal species that does not have a pain assessment scale available in the literature. We aimed to develop and validate the Unesp-Botucatu goat acute pain scale (UGAPS). After video observations of goats before and after castration, the scale was developed based on a list of behaviors and experts’ opinions. The videos were watched by four observers unaware of the time point when the videos were recorded. After the scale was statistically refined, UGAPS showed very good (≥86%) agreement between the same evaluator assessment of pain scores observed at the same videos assessed in different time points and very good agreement (≥85%) between evaluators’ assessments, adequate interaction between its items, 99% precision to detect an absence of pain before surgery, 90% precision to detect pain after surgery, and an indicative score ≥3 of a total of 10 points suggestive of analgesia in goats submitted to castration.AbstractWe aimed to develop and validate the Unesp-Botucatu goat acute pain scale (UGAPS). Thirty goats (5 negative controls and 25 submitted to orchiectomy) were filmed for 7 min at the time points 24 h before and 2 h, 3 h (1 h after analgesia), and 24 h after orchiectomy. After content validation, according to an ethogram and literature, four blind observers analyzed the videos randomly to score the UGAPS, repeating the same assessment in 30 days. According to the confirmatory factor analysis, the UGAPS is unidimensional. Intra- and interobserver reliability was very good for all raters (Intraclass correlation coefficient ≥85%). Spearman’s correlation between UGAPS versus VAS was 0.85 confirming the criterion validity. Internal consistency was 0.60 for Cronbach’s α Cronbach and 0.67 for McDonald’s ω. The item-total correlation was acceptable for 80% of the items (0.3–0.7). Specificity and sensitivity based on the cut-off point were 99% and 90%, respectively. The scale was responsive and demonstrated construct validity shown by the increase and decrease of scores after surgery pain and analgesia, respectively. The cut-off point for rescue analgesia is ≥3 of 10, with an area under the curve of 95.27%. The UGAPS presents content, criterion, and construct validities, responsiveness, and reliability to assess postoperative pain in castrated goats.