Researchers at the College of Veterinary Medicine at Iowa State University examined the benefits of walking and swimming in dogs that had undergone surgery to repair a rupture of the anterior cruciate ligament (ACL). The dogs were filmed while swimming and walking on a treadmill and the angles of extension and flexion of the knee, hip, and tarsal joint (hock) were calculated. The results were also compared to those from healthy dogs who did not have any disease of the knee.

Swimming was found to result in greater range of motion of the knee and hock than walking. The researchers suggest that for dogs recovering from ACL surgery, for whom range of motion following recovery is a concern, including swimming in the rehabilitation would likely result in a better outcome than walking alone.