2 year‐old thoroughbred filly presented with right hind lameness. The attending veterinarian was called to the farm, upon tapping the coffin joint,fluid revealed a white count of 100,000+,the joint was then flushed and infused with amikacin. The veterinarian prescribed hyperbaric oxygen therapy at The Sanctuary along with continued antibiotics. After the third consecutive treatment the joint was tapped again and the white count in the joint fluid had dropped to 4,000+. The veterinarian felt that the hyperbaric oxygen therapy cured the joint infection.