Instructions
Feed your chihuahua after the family has finished eating as the dog knows that alpha dogs eat first and subordinates eat second. Make the chihuahua sit and wait quietly before you give it food.
Do not allow your chihuahua to sleep on your bed or to jump up on furniture as higher positions will only reinforce its dominance. Only pick your chihuahua up off the ground when it is in a calm state of mind. Do not pick it up if it is demanding attention from you. If the chihuahua growls at others while you are holding it say "no" in a firm voice and immediately put it down on the floor.
Take your chihuahua out for a walk every day to prevent it from acting aggressively as a result of frustration. The chihuahua's small size does not mean that it doesn't need exercise. Always walk slightly in front of your chihuahua to show it that you are its leader rather than its follower. Stop your dog from pulling, acting aggressively toward other dogs or trying to overtake you by catching the behavior immediately, before it escalates. Say "no" in a firm voice and tap the dog on the shoulder.
Enroll your chihuahua in obedience training classes to encourage it to look to you for direction and follow your commands.
How to Tame an Aggressive Chihuahua
A balanced Chihuahua has an affectionate and cheery temperament, making it an ideal companion dog. However due to its small size this breed is often babied by its owner and not given adequate leadership. This can result in the chihuahua developing "small dog syndrome," causing it to view itself as the alpha dog of its pack or family, according to the Dog Breed Info Center. Dominance can cause a number of behavior problems, including aggression. Stop your chihuahua from acting aggressively by showing it that you are the pack leader.