Teaching your dog to cast is basically teaching him direction by signal. You can use voice commands, hand signals, whistles, or gestures to communicate to your dog which direction you would like him to cast. Sending your dog into one direction or another is imperative if you are teaching your dog to hunt or work. Search dogs are often cast for work. If your dog is a retriever, a search dog, a hunter, or a working dog he will need to understand casting. A hunting dog will need to know which direction his prey is in. It is also imperative for a hunting dog to know in which direction he needs to go to remain safe. You do not want to teach your dog to run somewhere and scare off potential prey or potentially be injured. Military dogs also learn to cast. Casting becomes necessary outside of day-to-day domestic life and more important in hunting and working dogs.
There are four basic casts when you are teaching your dog this skill. The left-hand cast, the right-hand cast, the back or over cast, and the recall cast are all commands you will need to teach your dog if you would like to train casting. Some trainers and owners also teach their dog to move left or right and some trainers may also teach a left back and a right back cast. No matter the position you teach your dog, be sure to be consistent and use the same signals time and time again. Casting basically takes your dog away from your control and into a direction where you would like him to go. Casting him back into your direction requires another recall command or signal to your dog.
To train your dog to cast, you should have plenty of treats and some toys to toss in a direction you would like your dog to go. If you plan to use a clicker or a whistle for signals, have this handy as well. To start off on the right foot, have your dog harnessed or collared and leashed. Casting takes time and patience, but more than anything training your dog to cast will be extremely repetitive training. Be prepared to train in several sessions over the course of several weeks.