If you are thinking about taking agility up with your dog, first think about how fit your dog is. Discuss with your vet any injuries your dog may have had in the past, and how this will affect his ability to enjoy agility. If your dog needs to lose weight, then think about increasing your daily walks, walk further or faster, or increase the number of smaller walks in the day if possible, to help your dog to lose weight before starting any fast work. Walking on the lead is the best exercise for obese dogs. If you have a puppy, wait until the dog reaches maturity before undertaking any high impact work, such as repeated jumping at speed. An immature skeleton or being overweight can lead to an increased risk in concussion injuries or affect joint development in the young dog.
While your dog is still unfit you can start to introduce the obedience aspect required for agility, and the agility equipment to your dog, in a safe environment and preferably with an experienced trainer. They will introduce the equipment slowly and help to increase your dogs confidence. The dog walk, weave, tunnel, and contact points can all be taught at a walk, on a lead. For the health of your dog, leave any jumping until his weight is close to normal for his size, breed and age. Your vet can help advise you when your dog is at a suitable weight to start jumping.
As your dog builds muscle, having him checked over by a qualified therapist can help prevent problems futher donw the road, the therapist will release tight muscles, this will help prevent muscles tears, and tendon strains, they can advise if the training can be pushed on or whether your dog needs to have less exercise for a while, allowing the body to repair and adjust to the increasing demand.
Remember to always warm both you and your dog up properly before starting any training, I have laid out some simple advice about warming up your dog in another article.
Being sensible and following the advise of your vet, trainer and therapist will help you and your dog to enjoy agility and help reduce the risk of any injuries occurring.