The first step to understanding why Chihuahuas are aggressive is to know the main causes of aggression in dogs. In this sense, and as we mentioned in the introduction, we are talking about a complex behavioral problem that is related to multiple causes, and whose treatment must be oriented to the specific needs of each dog.

Next, we will review the five main reasons why a dog, in this case a Chihuahua breed, becomes aggressive. 

Genetic heritage

It is impossible to deny that there is a genetic component that can favor the manifestation of aggressive behaviors in our dogs. To put it very simply, there are certain dogs that are naturally more likely to resort to aggression as a resource to deal with certain situations. And the chihuahua is one of them! In fact, the results of the aforementioned Dognition study, which has suffered criticism for being based almost exclusively on the considerations of the guardians of the evaluated breeds themselves, reinforce the previous conclusions published by the American Society for Temperament Testing. This organization had already observed, through a series of behavioral tests, that the American pit bull terrier was positioned among the most tolerant breeds, having reached the astonishing figure of 87.6% in the positive temperament test, and the American Staffordshire terrier did so. followed very closely with 85.7%. Meanwhile, Chihuahua dogs recorded a score of only 68.8% tolerance< to i=11>, according to the same parameters.

However, there are a series of good practices that, as guardians, we must use in the education of our dogs to allow them to assimilate other resources to deal with complex situations, leaving aggression only for extreme circumstances. So, when a Chihuahua dog has access to a good education, and mainly adequate socialization, that genetic predisposition becomes less determining for his behavior.

Fear

This point is directly related to the previous one, since, as we saw, aggression is a resource that a dog resorts to when it needs to feel safe in difficult contexts. So, when a dog is afraid, and mainly if he perceives that something or someone puts his physical or emotional integrity at risk, the chances of him reacting in an aggressive manner are much higher. But the relationship between fear and genetic inheritance goes further because it has been observed that some breeds of dogs are also naturally more fearful than others. However, this predisposition towards fear usually varies due to the different factors of non-social fear in dogs, such as heights, loud noises and fear of strangers or the unknown. In this sense, size and body composition seem to play a key role in the dog’s response to fear, since small dogs tend to show a greater predisposition towards fear than large dogs.

It is no coincidence that Chihuahuas are both among the most fearful dogs and among the dog breeds with the greatest predisposition to aggressive or exaggerated reactions when faced with unknown or intense stimuli. Thus, they reveal a high predisposition to fear heights and surfaces, something that is probably related to their small size and low muscle density. But, on the contrary, they are brave when it comes to defending what they consider valuable resources for them, as we will see below.

Resource protection

All dogs have the natural need to protect the resources they consider key to their survival and well-being. But when a dog feels the need to resort to aggression to protect its resources, we are facing a case of “resource protection”, which many guardians associate to possessive behavior.

Let us clarify that when we talk about “resources” we are not only referring to material goods, such as food, toys and the territory itself, but also to immaterial resources, such as the attention and care of their guardians. For example, a dog that does not allow anyone to approach its guardian is a clear example of the manifestation of resource protection, where the dog manifests a series of aggressive behaviors with the intention of preventing another animal or staff from competing with it. him for his attention.

Likewise, the protection of resources can also manifest itself towards the tutors themselves. For example, if your Chihuahua won’t let you near him while he’s eating or if he growls at you when you try to take a toy out of his mouth.

Problems in socialization

This is probably the main cause that explains why Chihuahuas are aggressive and is closely related to the previous ones. It is during the socialization process that a dog can assimilate that variety of resources that allows it to deal in a more balanced way with all types of difficult situations, understanding that aggressiveness is an extreme resource that should only be resorted to when its integrity is really in question. danger.

Therefore, a dog that has not been properly socialized becomes more prone to fear, has more difficulty communicating with other dogs and interact peacefully with other individuals. All these reasons reaffirm the importance of socializing your Chihuahua from an early age, and preferably between its third week and third month of life, as this is when the critical period of dog socialization occurs, where recognition of the species should occur. friends.

Another key factor for the stability of a dog’s behavior is the coexistence with its mother and siblings during the first weeks of its life. During this period, the puppies’ first and most fundamental learning occurs, and the mother is in charge of teaching her pups the fundamental codes of her communication and social behavior. For this reason, puppies that are separated prematurely from their mothers and siblings tend to have more learning and interaction difficulties in adulthood, as well as a greater predisposition to complex behavioral problems, such as aggression.

Stress and redirected aggression

In this case, generally, we are talking about a dog that lives with such a high level of stress that accumulates a lot of tension to the point of resorting to aggression to alleviate it. This aggressive response can manifest itself towards any person or other animal, even if they are not the source of the stress, and that is why we speak of redirected aggression. Know the «Stress symptoms in dogs» in this other post.

However, fear can also act as a driver for redirected aggression. Generally, we are talking about a dog that has been systematically exposed to situations that cause great fear, and any individual or stimulus that can cause a disturbance in its environment can end up activating an aggressive reaction to protect itself, even if this individual has nothing to do with it. the previous situations in which the dog has been involved.

It should be remembered that systematic exposure to fear has harmful repercussions on the behavior and mental health of dogs. One of them is to reduce its confidence until it makes the dog insecure, or in more extreme cases, causing it to develop a general panic towards people or any other individual. 

Health problems

Beyond stress, there are many diseases and metabolic disorders< a i=4> that can alter a dog’s behavior, increase its sensitivity and, consequently, the tendency to resort to aggression to protect itself in a context where it feels particularly vulnerable.

Something similar usually happens with older dogs, which become more prone to numerous health and behavioral problems, both because their senses are progressively impaired, as because their immune system is becoming weaker. 

Maternal aggression

If you share your home with a chihuahua that is pregnant or has just given birth, it is very possible that this aggressive behavior is associated with the need to protect herself and her puppies a>. Remember that dogs need a series of care to have a healthy pregnancy and a safe birth, but it is also essential to respect their space and be very careful when handling their puppies.

Aggression associated with sexual behaviors

If you have two or more dogs chihuahuas of the same sex, you will see that, upon reaching puberty and consequent sexual maturity, they will begin to show a series of behaviors associated with sexual desire and reproduction, which tend to intensify during the periods of heat in females, while in males they can be present all year round.

In addition to mounting, escapism and marking, it is also common to observe aggressive behaviors related to competition for resources present in the environment, which includes sexually receptive partners. Furthermore, intersexual aggression is strongly related to dominance towards members of the same sex, although it can also be directed towards the opposite sex less frequently.

However, it is important not to confuse dominance with aggression in dogs, because while the former manifests itself naturally in interactions between dogs and has to do with the hierarchical order of their species, the latter is a behavioral problem. 

Now that we know the main reasons why Chihuahuas are aggressive, let’s move on to the questions that really keep guardians up at night: what to do with an aggressive Chihuahua.

We are going to divide the answer into two different moments where the tutor’s action is decisive. The first, which we will deal with in this section, is what to do immediately when a Chihuahua becomes aggressive to calm it down and prevent it from causing harm to itself and other individuals. The second has to do with the treatment of aggressiveness, which must be guided by a professional, and which we will talk about in the next section.

What to do if my Chihuahua is aggressive towards other dogs and/or people?

If you perceive that your Chihuahua shows signs of discomfort, stress or directly aggression towards another dog or a person, the best thing you can do is stay away from the individual or stimulus that produces this negative reaction in him. Next, you can try to attract his attention to something he likes, whether it be a treat, a toy, or an activity (for example, a walk if you are indoors, a game like catch, etc.).

Furthermore, to prevent these situations from recurring, it is highly recommended that you always take your dog for a walk on a leash and muzzle, getting him used to it beforehand through positive reinforcement.

What do I do if my Chihuahua is aggressive towards me?

If your Chihuahua is aggressive towards you, it is best to walk away and leave him alone in a room where he feels safe until he has calmed down. It is normal for you to have a lot of questions at that moment, like “why does my chihuahua bite me?”, and you get sad or even feel a little annoying, but remember that the first and most important thing is to prevent the stress level from continuing to increase. And for that, it is best to respect your dog’s space and take the time to think about what happened and why your dog reacted that way. 

Once the critical moment has passed and having managed to calm an aggressive Chihuahua, it will be important to understand why these aggressive responses occur and what we should do to that they stop happening. Here we are not talking about a dog that has been aggressive at a specific moment, where extreme fear or a specific threat has caused it to resort to aggression to preserve his well-being or even to defend his guardian or his home. Any dog ​​can resort to aggression as a resource to deal with threatening circumstances, and this is part of the nature of dogs (and almost all animals, even humans). When we talk about the need to treat aggression in dogs, we are referring to a dog that shows a pattern of aggressive behavior, or that resorts to aggression to deal with a series of daily situations that make it feel uncomfortable. . To simplify, what requires treatment is not a specific reaction compatible with the context, but a behavioral problem that manifests itself through recurrent or permanent aggression.

So, if your Chihuahua dog has become aggressive, either with you, with other people or with other animals, the first thing you should do is seek the guidance of a veterinarian a>. This professional will help you rule out underlying diseases and interpret your dog’s symptoms and behaviors to understand the reason why he has become aggressive. Based on this information, the professional will be able to establish the most recommended treatment guidelines for aggression according to the needs and characteristics of your best friend.expert in canine ethology. Even better if you can consult with a veterinarian

We know that on the Internet you will find a lot of recommendations on how to control an aggressive Chihuahua, but the reality is that many of them lack foundations and can be dangerous if applied incorrectly or by someone without experience in managing aggression in dogs.