There is no doubt that every dog has an individual personality and also a built-in ancestry personality. 

A dog’s temperament changes significantly, such as if the dog is trained and how the dog has been raised, all play a big part in a dog’s temperament.

Aggressive To Other People: Why?

Your Chihuahua has an instinct to protect you and use aggression as their main deterrent towards other people or dogs. It would help if you took this responsibility away from your dog by showing good leadership qualities through training. This way, your Chihuahua won’t feel the need to protect you and, in turn, be less aggressive. Another possibility is being ill-treated and feeling pain.

Let’s delve into this a bit deeper, and after my article, you will have clear guidance on what you should do to resolve the aggression.

Despite their size, chihuahuas are considered one of the best guard dogs. 

These small dogs have feisty and big personalities. They are not afraid of intruders. If necessary, Chihuahuas do not think twice before biting a stranger who is threatening their owner.

In many ways, it is nice that your Chihuahua is protective of you, which means they love you. But it can be risky! You wouldn’t be reading this if it wasn’t a problem.

Your dog will assess every potential person and dog as you meet them. If your leadership is non-existent, then every dog and person you meet on walks or when you have guests over your Chihuahua will react.

I bet your Chihuahua will bark, growl and even bite.

Your dog is doing this unwanted behaviour to protect you and their space, and they do not trust that you can fulfil this role, so they are taking it into their own hands, or should I say paws! 

Ancestry Personalities Traits: Aggression Genetics

Below are some of the leading inbuilt personalities of a Chihuahua passed down to them through generations. These personalities prove they are prone to bark, growl, and bite.

You can understand from the below that Chihuahuas are likely to bark, growl and bite because of these built-in traits. 

The easier you come to terms with these, the better it will be for you to realise what you need to do. Your leadership role and duties, are important to a Chihuahua.


Chihuahuas have been considered one of the best guard dogs, thanks to their possessive and protective nature. These dogs are protective of their owners and space instinctively. That is why they instantly become defensive whenever they meet a stranger and get ready to attack the person if necessary. 

Suspicious and Possessive

Chihuahuas tend to love one person more than another in their life. They are highly suspicious of strangers and other dogs who try to come near them. Being highly possessive, these dogs do not like new faces and will react.


These small dogs are incredibly courageous and are not afraid to show their dominance to others. Considering their size, they are fearless dogs and will use their barking, growling and biting power to control a situation. In their minds, they are just as big and scary as a German Shepherd.

Mix The Traits

With these personalities, zero leadership and zero training, a Chihuahua will give off an aggressive nature to other dogs and people.

Your Chihuahua is doing their duties, or so they think.

It’s more than likely that your Chihuahua is not aggressive as such. For example, do they lick and cuddle you when you’re on your own? If so, then an aggressive dog wouldn’t do this. They look aggressive when they react because of their traits and lack of leadership. 

Many owners get aggression confused with normal dog reactions to protect and dominate whilst feeling anxious.


  • Your dog will protect you if they believe you are incapable. This results in barking, growling, and biting strangers and other dogs. 
  • Your dog will dominate you if you don’t show leadership qualities. This results in barking, growling, and biting strangers and other dogs. 
  • Your dog will have anxiety because they believe you can’t protect them and yourself. This is especially seen in submissive dogs. This results in barking, growling, and biting strangers and other dogs.

Solution To Resolve Chihuahua Dominance

To resolve the signs of aggression, barking, growling and biting at other dogs and strangers. You must complete the basic training with your dog. It’s your form of communication with your Chihuahua, and it’s a time to prove to your dog that you are the leader, not them. It’s also a time to reassure your dog and give them confidence! Along with socialisation to desensitise them to other dogs and people. Only then will you resolve the unwanted behaviour of aggression!

It’s a long process, but if you love your dog and want to be a responsible dog parent, I’m afraid it’s time to roll up those sleeves and get started. 

Training Your Chihuahua

Training your dog to listen to you and look for your direction is essential for a Chihuahua. Going through each basic training command will resolve any aggression in Chihuahuas. It will give your dog confidence in themselves and confidence in you. Just because your Chihuahua is a small dog doesn’t mean they don’t need training. 

There is no reason why you shouldn’t master these basic commands with your Chihuahua.

  • Sit
  • Stay or Place
  • Come or Here
  • Down
  • Heel
  • Leave it

Making Friends Isn’t For Every Dog

You Chihuahua may never become best friends with another dog, nor should you push them to be best friends. However, Your Chihuahua should be able to tolerate them at the very least and not react as much. Like humans, some dogs won’t get along with others; this is normal!

You can try to socialise your dog, which can help desensitise some dogs, but if they are not into meeting dogs. Don’t push them!

Aggression can also be caused by:


Chihuahua dogs can also suffer from post-traumatic stress disorder. If your adopted dog comes from an abusive family, he may showcase excessive aggressive behaviour. 

Suppose you are already aware of your dog having been mistreated in the past, and you have been unable to resolve it yourself through training. In that case, you will need to seek help from a person specialising in dog behaviour modification. 

Try to find out about your dog’s past. If in doubt, seek help from a person specialising in dog behaviour modification. They can find the aggression triggers and help you and your dog overcome the behaviour issue.


A Chihuahua can react aggressively to strangers, dogs and owners because they are in pain. So if your Chihuahua is coming across as aggressive towards you, especially when you pick them up or touch a part of them, and they react, this is a good indication that they are in pain. A trip to the vet will be your next step for a check over.

Want to learn about the Chihuahuas dog breed history? I have written a date timeline line of gathered information from the early years until modern-day Chihuahua history.


Understand that your dog is most likely not aggressive. Your dog is reacting to what they believe it should be doing. You must take ownership and lead your dog through training.

By training your Chihuahua, you take the responsibility away from your dog to react.

I hope this has encouraged you to take training time with your Chihuahua and build many happy memories together.

This is my boy in the picture below, and he is very submissive towards other dogs. He doesn’t have a problem with dogs. His aggression towards strangers who come into the house was the problem. Errol was anxious, and to help him, I to built his confidence in me through training. He only occasionally barks when someone comes to the door, but he’s no longer aggressive or barking excessively. Errol understands his role when someone knocks on the door now.

Chihuahua Dog on a rug playing with tennis ball
Errol the Chihuahua

Good Luck!

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