Dog agility is a sport in which a handler directs a dog through an obstacle course composed of jumps, tunnels, and contact obstacles in a race for both time and accuracy. Dogs must run off-leash with no food or toys as incentives. The handler can touch neither dog nor obstacles.
Dog agility is the fastest growing canine sport. There are 5 major dog agility organizations in the United States responsible for sponsoring agility competitions and generally "policing" the sport: AKC, USDAA, CPE, UKC, and NADAC. Training and competition for young people is also available through the 4-H dog project.
Each of these organizations offer their own titles that cannot be mixed and matched. For example, if you earn an advanced title in AKC, you must still start in the lowest level of USDAA. Each of the organizations uses basically the same obstacles, but there are slight differences in the specifications and even a few obstacles that are unique to one or more organization. The rules also differ from organization to organization.
These pictures show Reba (biblack) or Brady (biblue) and Doug on a typical course composed of tunnels, weave poles, teeter, A frame, dog walk, and jumps.