Chihuahua aggression is a big subject and is often very misunderstood. Chihuahuas are great dogs, full of character and charm, but they can be feisty, and they are very much a “bite now and ask questions later” kind of dog.

Chihuahua aggression (biting, growling) is usually driven by fear, over-arousal, or anxiety about what’s going to happen next. This can escalate to prediction, the dog exhibits an aggressive response when nothing much has happened, but the dog thinks it’s going to. For example, a dog that has had its nose tapped or water squirted at it will become watchful, and when their owner moves their hand innocently, the dog becomes worried and may bite.

Dogs are not born aggressive; this is a learned behaviour that develops from how they’ve been handled and the lessons they’ve learned so far. Often this starts in puppyhood, how the dog is handled or through training methods that impose unpleasant stimuli on the dog.

Understanding the ladder of communication can be very helpful. Dogs will communicate “I don’t want something” in various ways. Every behaviour on this ladder is a “no” from the dog.

But often small dogs get ignored as they are easy to manhandle, so the dog escalates up through the ladder to bite. This then becomes a rehearsed response to your movement.

An aggressive dog is a dog that feels the need to defend itself from you. This can start innocently enough, for example, trying to put on a harness or pull a jumper over the dog’s head. The dog doesn’t want this interaction, but the owner ignores or doesn’t see the dog’s efforts to communicate “no” and continues until the dog escalates up through the ladder of communication to bite.

Some people assume aggression in dogs is about domination or the dog trying to be “top dog,” and this takes them down a very unpleasant training path that will often result in the dog’s behaviour becoming worse. Aggression has nothing to do with trying to be alpha — it’s just plain old fear about what’s going to happen next and the dog feeling the need to defend itself.

Chihuahuas are prone to some of the worst training advice I’ve ever seen. It must be something to do with their size, as people wouldn’t spray a German Shepherd in the face with vinegar, not twice anyway. (Honestly, I took this post down from our group this afternoon.) When treated like this, dogs become pessimistic and worried. Some shut down, but a breed trait is “active coping” (lunging, barking and biting), so they tend to come out swinging.

Chihuahuas are one of the most surrendered dog breeds and the most euthanised, and this is often down to behaviour.

Chihuahuas get surrendered because they become labelled as “psychotic” or “untrainable,” when the issues lie with how they have been handled and the training methods used. I blame social media squarely for this. There are hundreds of huge, unmoderated chihuahua groups giving out terrible advice to owners, as well as dogs being paraded in outfits for TikTok and Instagram.

Then you have the posts that showcase chihuahua aggression as amusing. They torment their dogs for clicks, dressing them up, provoking reactions, and filming fearful behaviour for laughs. It might look funny online, but it’s really normalising stress and fear, not cuteness.

But the good news is, if your chi is aggressive, making changes to handling, using games to grow optimism, and working on a consent-based protocol can switch a dog’s mindset.

For more on Chihuahua aggression and behaviour tips, visit our YouTube channel for free videos and guidance on training.

If you’re trying to rehabilitate aggression, our Chihuahua School can help with a guided approach to building calm and confidence. With patience and the right support, even the feistiest Chihuahua can learn to feel safe again.