Paul Reddam’s I’ll Have Another, a hopeful for this year’s Kentucky Derby, has been automatically placed on the veterinarian’s list in California after undergoing shock wave therapy on his back, which reportedly has a tendency to "tighten up a little."

"It’s just a pulse that brings blood to an area," Reddam said. "The horse had absolutely nothing wrong with him. (Trainer Doug O’Neill) just did it because he could do it, and his owner will pay for it. He’s just leaving no stone unturned. In California, you can’t use it within 10 days of an upcoming race, so you have to report it and go on the vet’s list."

Extracorporeal shock wave therapy (ESWT) is a noninvasive modality used to stimulate healing, particularly in ligament, tendon, or boney structures. A shock wave is a high energy sound wave that rapidly increases pressure as it travels through tissue–rapid and intense pressure changes result in cavitation, the formation and instantaneous collapse of tiny bubbles. Because these energy waves are generated from outside the body, this therapy is referred to as extracorporeal.

"Everything is going along like clockwork and he’s going to work again on Friday and then ship to Kentucky on Saturday," Reddam said