It is a non-stressful form of exercise and can be as basic as soaking sore feet, or tired muscles, in a warm bath, submerge the body or part of the body in a spa bath or swimming in a pool, an underwater treadmill or other water activities and massage provides a range of motion or exercise to limbs, bones, joints, muscles or nerves.

The primary advantage to Hydrotherapy over traditional methods is that it is a weightless environment that promotes the use of the limbs, and provides a range of motion and movement generally not attainable with normal exercise or rehabilitation programs.

During the exercise the animal can move a limb with minimal stress or strain, thus allowing the muscle to move and strengthen and allow the tendons and ligaments to tighten up. Dogs that refuse to put weight on, or even use a leg following surgery will typically use the leg without any discomfort in the swimming stroke.

In order to appreciate the benefits of Hydrotherapy, one must understand the basic principles and properties of water including buoyancy, viscosity, resistance, hydrostatic pressure, surface tension and the impact of the water temperature.