SYRCLE has developed a Risk of Bias (RoB) tool for animal studies, based on the Cochrane RoB tool, adapted for animal intervention studies. The tool includes 10 items addressing selection bias, performance bias, detection bias, attrition bias, reporting bias, and other biases. Half of the items align with the Cochrane RoB tool, while the others have been revised or are new, reflecting differences between RCTs and animal studies. The tool includes signaling questions to facilitate judgment and enhance transparency. It aims to improve the critical appraisal of evidence from animal studies, thereby enhancing the translation of animal research into clinical practice. The tool is designed to assess methodological quality and address specific biases in animal experiments, such as inadequate randomization, lack of blinding, and housing conditions. The tool also includes considerations for random outcome assessment and reporting bias. Inter-observer agreement was evaluated using Kappa statistics, showing good consistency for most items. The tool is intended for widespread use to improve the quality of animal studies and promote evidence-based research.SYRCLE has developed a Risk of Bias (RoB) tool for animal studies, based on the Cochrane RoB tool, adapted for animal intervention studies. The tool includes 10 items addressing selection bias, performance bias, detection bias, attrition bias, reporting bias, and other biases. Half of the items align with the Cochrane RoB tool, while the others have been revised or are new, reflecting differences between RCTs and animal studies. The tool includes signaling questions to facilitate judgment and enhance transparency. It aims to improve the critical appraisal of evidence from animal studies, thereby enhancing the translation of animal research into clinical practice. The tool is designed to assess methodological quality and address specific biases in animal experiments, such as inadequate randomization, lack of blinding, and housing conditions. The tool also includes considerations for random outcome assessment and reporting bias. Inter-observer agreement was evaluated using Kappa statistics, showing good consistency for most items. The tool is intended for widespread use to improve the quality of animal studies and promote evidence-based research.