Of course, there is a good reason for this. Younger dogs are still growing. If you try to force them to learn advanced or difficult tricks or routines, it is possible that you will stunt their growth or cause some long term damage. The second thing is that it is important to keep the dog's physical makeup in mind. It should be obvious that small breed dogs with shorter legs cannot always perform jumps. Larger dogs, on the other hand, may have difficulty with tunnels. When you find a good school that provides dog agility training, they will take all of this into account. A good school will provide a curriculum that is appropriate for your dog's breed and size. It is important for the owner's attempting to train their own dogs to take these same factors into consideration. It is a common mistake to assume that dog agility training includes punishment for your dog when they do not perform as expected. Many experts say otherwise. It is much more effective to reward your dog when it performs well. Different trainers use various methods when training dogs. You can use clickers, treats, or positive reinforcement for training your dog. Do your research and discover which method appeals to you. Remember that dog agility training should be fun for both you and for your dog. Dog training should not be a chore or a trauma for either one of you. It is also important to remember that not all dogs will respond in the same way to dog agility training. The plain truth of it is that some breeds are simply too skittish or hype to respond to commands. It is important that you do not allow your expectations to spoil your friendship with your dog.