Instructions
Teach a bark command by enticing your dog to bark during play. Say "speak" or a similar command and then run around with your dog's favorite toy. Tease him until he barks. Say "speak" again as he barks and reward with a game of tug or food reward. Repeat until your dog barks on command as soon as you pick up the reward toy or treat, which should be the same every time.
Extend the amount of time barking by only rewarding your dog when he stops on command. To teach this, say "OK" or "done" when you would like your dog to stop. Initially, say it before your dog would naturally stop. If she doesn't stop, turn your back and ignore her until she does. Then, give the reward. Build up until your dog can bark for 30 seconds to 1 minute.
Decide what you want your final cue to be: a knock on the door, door bell, jiggle of the gate or other cue. Make that noise, give the command and pull out the toy. Reward your dog for barking until you give the end command. Practice until you don't have to give the command.
Invite friends or family members to give the cue when your dog isn't expecting it. If your dog barks without receiving the command, give a big reward, using your dog's favorite treat or toy.
To teach your dog to bark on leash, add a hand signal to the command when on leash. Give the signal, such as tightening of the leash or moving your hand a certain way, and then give the verbal signal. Reward your dog with a treat or game when he barks until you give the end command. Practice until he can do it with the hand signal only.
How to Make a Dog Bark at Strangers
Persistent dog barking usually isn't desirable, but many owners acquire dogs to protect them from strangers. Most protective dogs, such as German shepherds, rottweilers and dobermans, have an instinct to bark, especially when their owner is nervous, so this is often a behavior that doesn't need to be trained. However, dogs can be taught to bark on command, in case you want to be assured that your dog will bark when necessary.