Are Chihuahuas Aggressive?
[All you need to know]

Aaron Rice Expert Dog Trainer
Written: January 17, 2022

Chihuahuas are small, cute, and cuddly. They look like they should be the perfect pet for any family. But if you’ve ever had a Chihuahua, then you know that this is not always the case. In fact, many people find that their Chihuahua can be one of the most aggressive breeds of dogs out there!

From experience, one of my neighbors has a Chihuahua, and she thinks it is not a good idea to pet him. She complains that her Chihuahua is always growling, no matter how much food you give him or what toys he has!

But think for a moment. Despite its small size, the Chihuahua is known for being aggressive. Hence, I think it is important to understand the reasons behind this aggression before figuring out what you can do about it.

Read on to learn more about why chihuahuas get upset and how to deal with them!

11 Reasons Why Chihuahuas Show Aggressive Behavior

If you see your Chihuahua showing dominant behavior, excessive barking, or any level of aggression, this section is for you. 

There are many reasons why a Chihuahua gets aggressive with people. And as with any problem, it is best to dig into the reasons to understand why they occur.

So, here are 11 reasons why your Chihuahua might act aggressively:

Lack Of Trust

When the dog has not been adequately introduced to people or other animals and has never bitten but is feeling threatened, there is often a lack of understanding that they are safe in their own home, which can lead to aggression. 

When a chihuahua does not trust someone, they are likely to act aggressively during the first meeting. The dog will typically bark at the person and may even growl at them. They will often be on edge and try to stay away from that person as much as possible. In this case, it is imperative to find out what made them feel unsafe and then try to change their behavior. 

Irritation From Ongoing Skin Infections

Like other breeds, Chihuahuas can get skin irritations or allergies. If their fur is irritated for long periods, they may show aggression on an owner’s hands as soon as they touch their coat. 

It is essential to know that when a Chihuahua has an ongoing skin infection, they may also develop aggressive tendencies. It can be difficult for you as a dog owner to tell if your Chihuahua reacts because of skin irritations or another medical problem. However, it is still beneficial to rule out any other potential problems. Hence, a visit to the vet can help. 

When the fur around their neck or face becomes irritated from allergies, the dog will typically growl when you come near them or pet them. They may also become aggressive if you try to clean the area of fur for them. If this is the case, it’s essential to take your Chihuahua to a veterinarian so they can properly diagnose and treat the problem.

Territorial Behavior

Chihuahuas are fiercely territorial and will not like visitors to your home. This is even more true if the dog feels threatened or they sense that you’re too preoccupied to give them proper attention. When a dog is guarding its territory, they are naturally going to be more aggressive when challenged.

It is essential to know that when your Chihuahua feels threatened or senses that you’re distracted, they may behave aggressively towards visitors. Dogs typically engage in this behavior when someone comes without an invitation or if they feel their attention is being turned away. 

It can be difficult for a Chihuahua owner to deal with this type of aggression in their own home because it seems unreasonable that a small dog can be so aggressive. However, Chihuahuas are territorial breeds, and that means they will do whatever it takes to protect what is theirs.

This type of aggression may also happen if you’re not home with your dog all day while they are alone. When a dog is guarding its territory, they are naturally going to be more aggressive when challenged. This can happen in both human and animal environments. The response will depend on the type of threat and how it makes them feel. 

If a Chihuahua is not getting enough attention from their owner, they may act like this as well. Suppose you see this behavior in your Chihuahua. In that case, it’s essential to give them plenty of attention and praise for good behaviors so that they don’t feel threatened by something in their environment.

A common cause of territorial aggression is the introduction of a new pet into the home. The more dominant pet, typically the dog, will feel threatened by this new animal and act aggressively towards it as a result.

Bite Inhibition That Has Not Been Established

When first taking in a puppy, teaching bite inhibition and proper introduction with new people is very critical for training. In addition, young Chihuahuas might need close supervision with children. 

It is not recommended that adults carry them loosely by the neck while biting since collars restrict air and breathing while biting to some degree, preventing them from choking if repeated often enough in a short period of time. Dogs’ necks are sensitive areas, and they have been linked with aggression in the past.

There are many ways that you can establish bite inhibition in your Chihuahua. One way is by playing tug-of-war with them in a safe environment. Another way is to allow them to chew on toys explicitly made for chewing. A final option is to teach them how to use their mouth gently, which will be easier if they have already been taught how to chew gently while playing with toys.


Chihuahuas are not immune to pain or illness like other breeds. However, they will get aggressive when in any amount of discomfort. Sometimes this is a result of age. Older Chihuahuas may show aggression because their senses start to deteriorate with old age inhibiting the dog from knowing who you are.

It is not uncommon for chihuahuas to be aggressive when in pain. It’s essential to take your Chihuahua to a veterinarian if you noticed any changes in behavior, as this could be due to a severe illness or condition. 

In my experience as a professional dog trainer, one of the most common reasons why chihuahuas may act aggressively when they’re in pain is because of old age. Older dogs may start showing aggression due to an impairment of their senses and diagnosis due to old age.

So, it becomes vital for us to take them to the veterinarian because it might be a severe illness or condition.

Fearful Aggression

Chihuahuas are small dogs, and as such, can be easily scared by anything new or unfamiliar for them. Therefore, fear is one of the most common causes of aggression in Chihuahuas. 

They might get aggressive because they’re feeling threatened. This is especially common in situations where the dog cannot escape from you or another person – like when it’s on a leash or your lap!

You must understand and comply with your dog’s body language to make them comfortable around you and other people.

Chihuahuas are also prey animals and can show fearfulness in certain situations. They might get scared, lash out, but they will stop once you or someone else has calmed them down enough.

Impulsive Aggression

Sometimes Chihuahuas will just do something without thinking about it, like grabbing a toy from your hand. This can lead to the dog biting your hand and showing aggression. On the contrary, if you do some impulsive action and your chihuahua feels threatened, they might react aggressively.

Chihuahuas can be startled easily, which may lead to aggression if you or someone else is near them when they are scared. So, ensure that the dog has time to acclimate and get used to what’s going on before trying to pet them.


Chihuahuas often get aggressive with other dogs because they are jealous. You might find them aggressive if you’re trying to pet both of them at once because they might feel threatened by another dog. They might defend their territory to keep from being harmed by a rival, resulting in aggression.

Unfamiliar Surroundings And People

Chihuahuas might get aggressive in new settings if they are taken from their home and put into a new environment. This is often because of the change in routine or surroundings – like being outside your house where more people are going by than usual.

When there is a new person near your dog, even if it’s someone you know, like family members, the Chihuahua might get aggressive because of all the unfamiliarity.

In some cases, this aggression can also be due to jealousy, like I mentioned in the previous point. When there are two other dogs around – the Chihuahua will want to be the only one getting attention and may show aggression. Jealousy is easier to spot because most Chihuahuas won’t get aggressive with their owners unless they are jealous.

A good way to avoid this is by getting your dog used to new people and surroundings before taking them there. Introduce the Chihuahua to many different people, places, dogs, animals – whatever it might be if they’re going into a new environment. This will help make things easier for you and your pet when you go to a new place.

Uncomfortable Physical Space

Chihuahuas need enough room to run and move around without feeling crowded, but also not too much as this can lead to aggression. Sometimes it’s better to let them explore the new space in their own time rather than pushing them.

You must ensure that the space is safe and there are no threats for them to react on. Otherwise, even the presence of an unfamiliar person or another pet can trigger a fight or flight response, and the situation can get messy quickly.

Inability To Communicate

Sometimes it’s hard for a dog who doesn’t speak our language (or has limited ability to do so) to communicate when they are feeling threatened, and this can lead them into a fight or flight response.

Understanding your pet’s body language will help tremendously since it is the only common language between you both. You can know when your dog is having an anxiety issue and when they are indicating medical issues. Putting some time effort into understanding pet psychology and body language can save lives.

What To Do When Your Chihuahua Is Aggressive

It’s an unfortunate reality that many pet owners have to deal with their little fluffy friend showing signs of aggression. 

When this happens, the owner needs to take steps to ensure the safety of everyone in the household, including themselves and other pets. Thankfully, some easy fixes can help reduce aggressive behavior from your Chihuahua!

Here are 9 things you can do:

Spaying Or Neutering

The pet should be spayed or neutered as soon as possible. Aggression in a dog can result from the frustration of not being able to mate with another. This may be why many older male dogs might show this behavior because they’re frustrated with their lack of mating opportunities. Spraying can be a deterrent against urine marking and territorial aggression.

Feeding Your Dog A High Quality, Well-balanced Diet

Diet plays a crucial role in your Chihuahua’s behavior. A dog can become aggressive because it is not getting all the nutrients that it needs in its diet, and this leads to frustration, which could lead to aggression.

This can help with weight control which in turn can reduce stress for you and your pet! Be sure to check for a medical issue or medical condition, if any. The best way is to ask your vet and decide the diet plan for your dog.

Daily Exercise

Dogs love activities of any kind, and for Chihuahuas, this includes running around a lot. Therefore, it’s essential to give them enough exercise so that they can release their pent-up energy and reduce the chances of it manifesting in aggression.

As you work on these things with your pet, be sure not to punish or show disappointment when they act aggressively, as this can lead to more aggression. Your purpose isn’t to punish them; your purpose is to help them!

If you adopted them, you could also ask the previous owner about previous exercises schedules. Alternatively, you can hire a trainer to deal with this aspect if you lack the time. 

Obedience Training

Training your dog in obedience and teaching them how to respond when feeling scared or threatened. This way, they know what is expected of them so that you can prevent aggression from happening. You can start by teaching your dogs basic commands and move up from there.

If you employ positive reinforcement training, your dog will be trained to associate good things with being disciplined and bad things with not obeying. Eventually, they will learn that they are rewarded for good behavior and not punished for bad.

Keep Your Chihuahua Busy

Provide them with things to do like chew toys or time outside in the yard so they don’t feel threatened and can release pent-up energy before it becomes aggressive behavior. 

Again, if you’re following an exercise regime with your dog, it would take care of most of the problem. However, if your dog has very high energy levels, you’ll have to find an outlet for them to release the energy. You can do this by taking them for a walk, playing with them in your backyard, or even going to the dog park.

Spend More Quality Time With Your Dog

This will allow you two to bond on a deep level and will give you a better understanding of why they might be aggressive in certain situations. The more your chihuahua trusts you, the less likely it is they will act aggressively.

Introduce Your Dog To New People Slowly

Even if it is someone you know, like family members or friends, the Chihuahua may get defensive and lash out because of all the unfamiliarity around them. This is especially true when there are other people around your dog. 

So, ensure that you introduce them to new people slowly and give them time to get used to that person. We’ve already discussed how unfamiliarity can trigger defensive actions and aggression.

Be Patient

It might be frustrating when your pup becomes aggressive, but it’s important not to lash out at them because it will only make things worse.

Use Natural Calming Techniques

There are some herbal remedies you can give your dog to help them relax, like Chamomile or Valerian Root Tea. Even giving a bath with lavender essential oil can be helpful in relieving anxiety and aggression because it’s so relaxing for the animal.

But if you don’t want to do that, you can also try to calm your Chihuahua by stroking their head or giving them a treat.

If your pup is still aggressive after trying these techniques, then it might be time to consider other medical options like medication from the vet for anxiety and aggression. 

How to Prevent Aggression in the Future

Aggressive chihuahuas can be a significant problem for pet owners. It is natural to feel tired of your Chihuahua’s aggressive behavior. I understand your frustration. If you’ve ever owned one or come across one often, you’ve probably experienced this firsthand.

Angry chihuahuas can easily frighten people and other pets, and they pose a safety risk to children. But it’s possible to train an aggressive chihuahua to stop being so aggressive with some simple steps!

Take a moment to reflect on what might have triggered the aggression. It will help you prevent it from happening again. What was happening just before the aggression? Did you walk into the house and see someone who startled you, for example? Was there too much noise at once? Did your dog feel threatened by another animal?

These are all things that you can consider. Furthermore, you’ll want to consider the dog’s diet as well. Often, dogs will act aggressively when they need more protein in their diets or if they have an allergy.

This is just one step in preventing aggression with your pup! The next thing might be to take them to the vet for an exam and see if they need any medication.

There are many options to prevent your Chihuahua from being aggressive, but prevention is always the most effective! So if you can try some of these things outlined here before aggression becomes a problem, I promise that you’ll feel much better about living with your pet.


Most Chihuahuas are mild-mannered and friendly little dogs that shy away from physical contact with humans – but some do not. Instead, they attack people, other animals, or the objects inside their homes with no warning whatsoever.

A lot of the problem can be traced back to improper training or an irresponsible owner who doesn’t know how to control their Chihuahua’s aggressive tendencies. But there are also a variety of other reasons why Chihuahuas might be aggressive.

The best way to prevent aggression in the future is by prevention – which means taking care of your dog and limiting their exposure to stressful situations or people they don’t know well. Follow the tips I’ve shared above to curb the tendencies. If you can understand and work with your dog patiently, you’ll have achieved something truly amazing. You’ll not get a pet that loves you but a best friend for life! 

And if you’re not sure about proceeding on your own, then see what medical options exist for treating aggression.

I hope this article has been insightful into the reasons why Chihuahuas become aggressive and how you can take steps to prevent them from becoming something more than a character trait for your family member.