Animals in sport are a specific form of working animals. Many animals, at least in more commercial sports, are highly trained. Two of the most common animals in sport are horses and dogs.
There are many types of animal sporting events, with varying levels of participation from humans. Some are solely between the animals while others use the animals in a lesser role. Most sports involve training, while some can also involve selective breeding.
There are some large-scale events that include animals in a variety of sports. A rodeo can comprise many different sports, ranging from bull riding to pole bending.
Racing is the most popular form of animal-related sport, particularly horse racing. Some racing events directly involve humans as riders while others see the animals race alone. In some sports the rider is not directly riding the animal, instead being pulled along. Examples of this include harness racing, dogsled racing and popular ancient Greek and Roman sport of chariot racing.