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Why Are Chihuahuas So Aggressive? Breed Temperament & Likely Reasons

Written by: Grant Piper

Last Updated on June 25, 2024 by Dogster Team

Aggressive chihuahua dog

Why Are Chihuahuas So Aggressive? Breed Temperament & Likely Reasons

Chihuahuas are little dogs that are full of personality. They are incredibly popular and can be found all over the world. However, some Chihuahuas seem to be extremely mean or aggressive. Why is that? What makes Chihuahuas so aggressive? Chihuahuas are aggressive for a number of reasons, and many of them are not unique to their breed. Here’s a bit about Chihuahuas as well as six reasons why Chihuahuas are aggressive.


Chihuahua History

Chihuahuas originated in Mexico, and they were a staple of the Aztec civilization. Legend has it that Chihuahuas were important to Aztec royalty. From their origins in Central America, Chihuahuas exploded in popularity. As the Spanish arrived and as Mexico moved into the modern era, more and more people fell in love with Chihuahuas due to their size and appearance. Some people believe that Chihuahuas were bred as pocket guard dogs, but there is no hard evidence to support this theory. Chihuahua aggression has little to do with their history as it does with their upbringing.

man holding back a snarling chihuahua dog

divider-dog paw

The 6 Reasons Why Chihuahuas Might Be Aggressive

1. Individual Personality

Some dogs are naturally more aggressive than other dogs. This is true of all dog breeds. Some Chihuahuas might be predisposed to aggressive behavior due to their genetics or individual personality. There are chill, calm, aggressive, mean, and sweet dogs of all kinds. The same is true of Chihuahuas. Some Chihuahuas are the sweetest and nicest dogs in the world, and some are aggressive and ornery. This could all be due to individual personality markers that you cannot see at first glance.

2. Lack of Training

Many people think that since Chihuahuas are tiny, they don’t need to be trained. Since Chihuahuas are loyal and friendly to their people and easy to grab, pick up, and manhandle, many people don’t spend the time and effort training their Chihuahuas. This can allow bad habits to creep in and cause Chihuahuas to act aggressively. Training can help keep Chihuahuas on the straight and narrow and prevent them from acting out in unfamiliar situations.

closeup of brown chihuahua
Image By: Daniel Martins, Unsplash

3. Lack of Socialization

Socialization is one of the best ways to curb dog aggression. The more you socialize your dog, the better the results. If you start young and introduce your dog to a variety of different situations, it can help reduce fear and anxiety, which can lead to aggression. The problem is that many people don’t socialize their Chihuahuas. People think that since their Chihuahuas are so small and harmless that they don’t need socialization. This is a mistake, and it is a big reason why so many Chihuahuas act aggressively in public. They are not socialized properly.

4. Chihuahuas Are Territorial

Chihuahuas are known for being extremely territorial. They will stake their claim to toys, beds, and people. If you accidentally mosey in on a Chihuahua’s territory, you could spark some aggressive behavior. Chihuahuas often have favorite toys, favorite places, favorite people, favorite foods, and favorite treats. Chihuahuas have been known to guard these things and use their most aggressive and scary demeanor to do it.

Chihuahua in the mountains
Image By: Julia, Pixabay

5. Chihuahuas Are Fearful

Chihuahua owners love to say that Chihuahuas are big dogs trapped in little dog bodies. But that is not the case. Chihuahuas are small dogs, and they know they are small. Fear is a powerful driver of aggression in animals, including dogs. That is why your sweet pup can turn aggressive at the veterinarian. Chihuahuas can feel fearful in many situations due to their size. This fear can quickly turn into aggression or faux aggression. Snarling, growling, baring their teeth, and barking are all ways that small Chihuahuas can try and ward off potential threats despite their diminutive stature.

6. Chihuahuas Can Have Painful Medical Issues

Chihuahuas are relatively healthy dogs, but they can develop some problems that cause them pain. Any dog that is in pain, especially strong or chronic pain, can be more prone to aggression. Chihuahuas are prone to teeth issues, luxating patella, and eye issues. Any one of these issues can cause pain, and pain can lead to aggression. These issues are also hard to diagnose, and they can linger, causing underlying pain in your dog for weeks or months without you realizing it, which can increase aggression. You should take your Chihuahua to the veterinarian for regular checkups in order to try and catch these problems before they get worse or linger.



Chihuahuas can be aggressive for any number of reasons. It can be a personality trait due to poor training, fear, territoriality, or pain. Chihuahuas seem to be more aggressive than other dogs because many owners do little to curb their Chihuahua’s problematic behavior due to their size. Many of these aggression triggers can be mitigated in Chihuahuas with proper training and socialization.

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Featured Image: Piotr Wawrzyniuk, Shutterstock

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