The beneficial effects of thermal water and mud treatment in the human medical field have been investigated and well known for many years. However, such treatment has never been studied and used in veterinary science. The aim of our study was to investigate how a mud treatment from Héviz Spa Lake affects the movement quality and flexibility of certain joints in horses. This medical mud, which is unique on the world, contain about 70-80 % thermal water from the Lake. Wet sludge was applied on the knee, hock, elbow, shoulder, back, stifle, front and hind cannons and fetlock joints for a period of eight weeks. Our results show, that the mud treatment from Héviz Spa Lake may have beneficial effects on the joints, playing important role in the locomotion of horses. The positive results of this experiment and the benefit of the water from the Lake in human field give us the idea to plan a balneotherapeutic equine medical centre next to the outlet canal of the Heviz Spa Lake. The main component of this centre is a covered balneotherapeutic equine walker. In this centre we could make complex hydro- and balneotherapeutic treatments for horses and we could use the medical mud as a supplemental treatment. This equine centre would be absolutely unique on the world.