Hyperbaric oxygen treatment (HBOT) is a therapeutic approach that involves administering 100% oxygen to patients at a pressure higher than atmospheric pressure. Originally developed for human medicine, this modality is beginning to gain popularity in veterinary medicine as well, especially in the care of various wounds. Hyperbaric oxygen chambers provide a controlled environment where animals can receive increased levels of oxygen, leading to numerous physiological benefits. This chapter will explore the principles, applications, and benefits of HBOT in veterinary patients. Contraindications as well as side effects are also discussed. HBOT effects on chronic wounds are specifically delineated and recent research involving hyperbaric oxygen therapy is reviewed.