Is there really a connection between keeping my horse in a stall and ulcers? Yes.Research has shown that 87 percent of domesticated horses have gastric ulcers and that stall confinement alone can lead to the development of ulcers. In a 2007 study, 15 normal, healthy horses with no gastric ulcer disease were put into individual stalls, and were given approximately 25 minutes of exercise per day. In this group of 15 horses, 11 developed gastric ulc [...]