The use of water to heal and rehabilitate animals dates back to ancient times. The ancient Greeks and Romans used seawater to treat injuries in horses and military animals. Animal hydrotherapy has become an important area of veterinary rehabilitation and physical therapy in recent decades. But modern hydrotherapy for dogs was introduced in the 1980s in the UK and the US, and has since spread around the world. There are different types of equipment, such as underwater treadmills, whirlpools and pools, to maximize the benefits of the treatment.