Aquatrainers for dogs are trained in animal physical therapy to safely and effectively train dogs in water. Hydrotherapy involves a combination of physical dog training and mental stimulation to improve a dog's physical and mental animal health. Aqua fitness trainers use a variety of equipment such as underwater dog treadmills, diving boards and toys to make the workout varied and engaging. Especially for dogs with joint problems and pain after injuries or for older dogs, the underwater treadmill is an excellent method for Hydro Rehab. It is also often used for prophylaxis.