Dog training dumbbell is intended for physical and mental development. First of all, let your dog to acquaint with the dumbbell. Its positive response to the dumbbell has to be encouraged with a treat giving or clicking.
The dog shouldn't chew and gnaw the dumbbell. Click and treat every time the dog holds the dumbbell in a right way.
Train the dog to walk with the dumbbell in its mouth.
Teach your dog a "Fetch" command. Click and treat when it grabs the dumbbell correctly.
Repeat these exercises until dog dumbbell taking becomes automatic.
The next step is to train your dog to bring the dumbbell back to you. Throw it and give a command to the dog to fetch the dumbbell. Click and treat when the dog gives it back.