Webster's dictionary defines a sport as recreation that includes physical activity. Most people would think of a sport as an athletic competition that demonstrates skills such as physical strength, stamina, agility, and speed. Humans recognized centuries ago that many animals possess such skills naturally and could be used in sporting events.
In the United States today, the major sports in which animals are involved are horse racing, greyhound racing, sled dog racing, rodeos, and organized animal fighting. With the exception of animal fighting, all of these are considered legitimate sports.
The legitimate sports probably began as friendly competitions between people wanting to show off their animals but the most popular evolved into businesses in which large amounts of money are involved. Horse racing and greyhound racing are intertwined with the legalized gambling industry. Rodeos and sled dog races largely depend on sponsors. Sponsors are companies that provide financial backing in exchange for being allowed to advertise during an event—for example, by placing advertisements around an arena, in programs, or on uniforms or vehicles. Even animal fighting has become a business of sorts, with profits driven almost entirely by illegal gambling.
In all of these sports, skilled animals can be quite profitable for the people who own, train, and manage them. Some animals involved in the sports industry are well cared for during their athletic "careers"; others are horribly abused. Sports animals that are less-skilled, injured, past their prime, or unwilling or unable to compete anymore have different prospects. Some retire and live comfortably, while others are sold to the slaughterhouse or are killed.
The fate and well-being of animals in sports lie in the hands of humans. To some animal rights activists, this is the root of the problem. They believe that animals should not be used by people for any purpose at all, including sports. Animal welfarists focus their attention on uncovering, publicizing, and outlawing practices in animal sports that they consider harmful to the animals. Animal participation is defended by insiders and fans who feel that their right to enjoy a recreational activity is being threatened by overzealous activists who do not understand the nature of these sports.