According to the USDAA, there are over 150 breeds of dogs, including mixed-breed dogs, involved in agility. Some breeds, like the Australian Shepherd and the Dutch Shepherd, are known for excelling at the sport. However, you should not let the fact that you have a Golden Retriever or a mixed-breed dog stop you from trying it. If your dog is playful and energetic, it will probably enjoy agility training.
RutRoh is an English Sheep Dog, born Deaf.  He is a wonderful dog and family companion, however, being deaf and living in Dallas, his safety was one of the reason he was brought to us for training.   His owners didn't want to have restrict him to be on a leash all the time.  They wanted him to be able to run and play and have a way to communicate with him when he was not in view of them.
You can start training your dog before they're of age to compete. Begin by working on basic obedience and teach your puppy to sit, lie down, come, heel, and stay. Your puppy will also benefit from attending training classes where they will learn basic obedience and get used to working around lots of other dogs and people. Having your pet take and pass the AKC Good Citizen Test is a helpful step.
If your dog exhibits a behavior you don’t like, there is a strong likelihood that it’s something that has been reinforced before. A great example is when your dog brings you a toy and barks to entice you to throw it. You throw the toy. Your dog has just learned that barking gets you to do what he wants. You say “no,” and he barks even more. Heaven forbid you give in and throw the toy now! Why? Because you will have taught him persistence pays off. Before you know it you’ll have a dog that barks and barks every time he wants something. The solution? Ignore his barking or ask him to do something for you (like “sit”) before you throw his toy.

Basic or beginner's obedience is typically a short course ranging from six to ten weeks, where it is demonstrated to the handler how to communicate with and train the dog in a few simple commands. With most methods the dog is trained one command at a time. Though there may or may not be a specific word attached to it, walking properly on a leash, or leash control, is often the first training required prior to learning other commands.
Unless you plan to keep your dog outdoors--and few of us do because it's not recommended--you'll need to teach your dog where to eliminate. Therefore, house training (also called housebreaking or potty training) is one of the first things you need to work on with your dog. Crate training can be a very helpful part of the training process. This includes house training as well as many other areas of training:
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