It's tough sometimes being the smallest dog on the block. If your Chihuahua growls at you or anyone he crosses paths with, it may be because he's unsure of his place within his world. Building up your Chihuahua’s confidence and making sure he understands his place is key in teaching him not to growl.
Chihuahuas have been bred to be companions for their owners. By nature, they are not automatically social dogs. They need to be trained to be social. Otherwise, they will come across as aggressive. Your Chihuahua may be growling at you or others because he needs training on how not to do this natural behavior. Teaching your Chihuahua to relax a bit around you and others will help to teach him growling is unacceptable.
Training your dog to relax isn’t as easy as simply telling him to relax. You are going to need to teach him that not growling is your expectation. Your Chihuahua will act aggressively and growl unless he knows other ways to act. The first thing you’ll need to do is socialize your Chihuahua. Once he knows his job is not to protect you and he is allowed to accept others in his world, people or pets, he’ll be better about reacting aggressively when around others. This is easier to train with a puppy, but you can redirect an adult Chihuahua as well. Training will just take more time and dedication with an adult. No matter the age, remember to reward good behavior and redirect poor behavior. Do not yell or hit your Chihuahua; these actions will only reinforce poor behaviors.
High-value treats are key in training your Chihuahua not to growl. Be sure to set aside some socializing time for your Chihuahua as well as short training sessions to build up respect and listening skills for your Chihuahua. Keep these training sessions short and only socialize at the beginning with people and dogs you know and are comfortable with. And always offer treats for your Chihuahua as well as the other animals you are socializing with.