How to deal with chihuahua aggression is something I get asked a lot. They have a reputation for being yappy and aggressive. If you are a chihuahua parent, then you may be familiar with the ‘curled lip of doom’ and the growl of disapproval towards strangers and the full on meltdown at other dogs. But you also know that, at home your chihuahua is adorable, cute, and hilarious. So, what on earth is going on?

Are chihuahuas more aggressive than other dog breeds?

I want to say no here, but the evidence does point towards yes. So why is that?

  • They are small, chihuahuas being the smallest dog breed. They naturally need to be wary of what’s around them and above them.
  • Another reason is that conventional training and socialization ideas do not generally work for chihuahuas and other toy breeds. Owners often start out with the idea of taking them to puppy class to then find out their dog is completely overwhelmed by the noise and larger breeds. They then either shut down and become a nervous wreck or they have a meltdown barking and lunging at the other dogs. This becomes a default behavior when they see another dog.
  • Owners then take to the internet and start copying adverse training methods like spraying water or rattling cans at their dogs.
  • Wholesale neutering of male dogs. Remove a male dog’s testosterone and you can turn your male dog into a fear barker. Research has shown that male dogs do better if left intact and females do better if spayed.
  • Willingness to let bad behavior go. Because chihuahuas are small some owners tolerate more. A snapping growling chihuahua can be laughed at, just search YouTube but a snapping growling German Shepherd is not so easily ignored.

Chihuahua aggression can manifest in different ways.

  • Growling at partners
  • Snapping at fingers when you take things away
  • Barking out the window
  • Snapping and growling when you move them
  • Chasing at the fence
  • Barking at other dogs on walks
  • Guarding their food

I’m sure there are other examples I haven’t thought of. So why do they do it, why are chihuahuas so keen to live up to their reputation of being yappy and aggressive? Why can’t they be more chilled out and friendly?

What chihuahua aggression isn’t

What I want to explain first is what chihuahua aggression isn’t. They aren’t protecting you; they don’t think they are a rottweiler and they don’t want to dominate every dog they see. I hear these things a lot from owners. They misunderstand their dog’s behavior and put a human narrative on what they see. The good news is it’s also unlikely to be anything you’ve done.

So, what is causing chihuahua aggression?

When a dog sees something, they will ask themselves ‘what does this object mean for me’ and is it good or is it bad? If they are barking at it then most certainly the answer is ‘it’s bad’. This will then instantly fill up their emotional bucket.

What is an emotional bucket?

If you follow my blog or ever listen to a Facebook live, you will hear me talk about a dog’s emotional bucket. Like humans they have one and like humans they fill and, once full, you get on overspill behavior. Think when you have ‘one nerve left’ and someone gets on it, and you explode.

Things that pay into a dog’s emotional bucket are interesting, fear, anxiety, feeling unwell or itchy. But also, happy events like fast play, a family member coming home or even a walk. Happy excitement and worry excitement fill up a dog’s bucket in the same way and have the same effect once your dog see’s something they are not sure about.

It’s also how quickly emotions drain. How fast your dog can calm themselves down and the size of the bucket. Dogs that are more chilled and relaxed are likely to have a larger emotional bucket that drains easily.


This will certainly be playing a big part in how your chihuahua behaves. Dogs tend towards pessimism and optimism in the same way humans do. A happy-go-lucky dog that runs up to everyone pleased to see them will lean towards optimism and the more cautious dog that hangs back, avoids things are more likely to be a little more pessimistic.

But before you worry your dog is a pessimist, this is a more natural state for an animal. In the wild, an animal that avoids ambiguity or things it’s not sure about is more likely to live longer and get to pass on its genes. An animal that sees no danger is more likely to get eaten. But this is not the case for our domestic dogs, so we want our dogs to change from a pessimist to an optimist.

Resource Guarding

Pessimism is most certainly playing a part in a dog that resource guards, a dog that worries food or possessions are going to be taken away and will snap or growl at people or other dogs that come near them in certain situations. This can get so bad that just walking past their bed while they are in it will get you growled or snapped at. This is not ideal.

Lack of confidence

Lack of confidence will certainly be paying into their emotional bucket and cause your chihuahua to bark at novelty or things they are not sure about. If you take your chihuahua out for a walk and someone appears in the field, or a crow fly’s down, or a carrier bag blows past they may start to bark at it. This is because they are unsure of the object and ‘what it means for them’ and this worries them. Building a tolerance of novelty or new things and growing your chihuahua’s confidence are key.


Being itchy, in pain or having a tummy upset will have a big impact on your chihuahuas demeanor.  Dealing with anything physical like this would be the first place to start when trying to unpick your chihuahuas aggressive behavior. Imagine constantly itching and not even being able to scratch it. This would make even the most even tempered of us a little tetchy. Diet will certainly be part of this picture and poor diets will often be the cause of gastric upset, itchy skin and sticky ears.


Whenever I start with a new client, one of the first things I will ask is what are you feeding your dog? If it’s a weak or dry diet, then this is where we will start to unpick their behavior struggles. A properly balanced diet is essential and dry food, no matter how science based the packet looks, is not a good diet. There is also a lot of research that shows a direct link between gut biome and brain function. So, step one is certainly make sure your dog is getting a good diet based on fat and protein.

Training methods

I am adding this in here because it’s so important to your relationship with your chihuahua. They bark a lot, and this can be annoying and get you into trouble with your neighbors or landlord. If they are barking, they are worried about something. Shouting, spraying them with water, using an air horn or another gadget to stop them are very common methods to interrupt this behavior. While it may do so it will be adding to the excitement of the situation and filling their bucket, so you will pay for it later and your dog will start to not trust you.


Being overwrought and overtired can also pay into behavior. Chihuahuas do like a snooze in the day, but they are also up and barking in a nanosecond. So, it’s not real deep rest. They need a good snooze out of the way of footfall, children, and general interference. If you have crate trained your chihuahua then use a crate or if not, then use a puppy pen and put them down for a good nap in the day.