My Dog Is Becoming Aggressive — What Do I Do?

One of the biggest warning signs for owners lights up when they notice their dog's behaviour has changed and they start showing signs of defensive or offensive aggression towards people, other dogs or animals of different species. If you're going through this, you're most likely asking yourself questions like "why is my dog becoming aggressive?" and "what can I do to stop my dog being aggressive?"

Before we start, we'd like to congratulate you for having decided not to ignore this behaviour in your dog and for seeking out the knowledge needed to help them. And now, we invite you to keep reading this article, since here you'll find the explanations you're looking for and some advice for dealing with this situation. Shall we start?

Why Is My Dog Becoming Aggressive?

The first thing you need to be clear on is that aggression in dogs is a serious behavioural problem needing proper treatment. This means there are no circumstances or contexts where we can consider it something "normal" or "acceptable", since it always points to the dog experiencing negative emotions or situations leading them to adopt a defensive or offensive stance, and this stance poses a risk for the dog themselves and everyone living alongside them or around them.

It also matters to understand an aggressive dog has nothing to do with a dominant dog. Dominance is part of different animals' behaviour codes, but it only shows up between individuals of the same species. That is, dogs will never be dominant towards their owners (humans), since they only express dominance when interacting with other dogs.

With these initial points clarified, the next thing you need to know is there's no single explanation for why your dog is becoming aggressive. Aggression in dogs has many possible causes, which can be linked both to internal aspects or their own body, as well as environmental factors and the training they receive from their owners. Below, we cover this topic in more detail.

Main Causes of Aggression in Dogs

Before moving on, we want to point out that genetics don't condemn any dog to aggression, and we say this because myths keep being spread about dangerous or naturally aggressive dog breeds. Although genetic inheritance does influence a dog's behaviour patterns, it's absurd to claim an animal, regardless of their species, is destined to become aggressive because of the information carried in their genes.

With that made clear, let's look at the main causes behind a dog becoming aggressive:

• Health problems: there are several illnesses that can cause pain, discomfort or even loss of sensory abilities in dogs, making them more vulnerable and leading them to feel the need to defend themselves in contexts where they sense their wellbeing is at risk. Blows and injuries can also cause pain and lead to behavioural changes.
• Inappropriate training: if the dog takes aggression on board as a means of communication, they'll use it to express themselves with other individuals and react to different stimuli that may come up in their day-to-day life. This commonly happens when punishment or violent methods are used in their training, making the dog understand they can resort to aggression to make themselves understood. Basically, a dog who's "trained" aggressively, whether by their owners or by whoever's responsible for their training, will tend to repeat this behaviour pattern with other individuals in their surroundings.
• No socialisation, or poor socialisation: a dog who hasn't been properly socialised hasn't had the chance to learn to interact positively with other dogs, people and animals, and also hasn't managed to learn to ignore certain stimuli to prevent reacting in an exaggerated way (for example, when exposed to loud noises or unfamiliar people). Because of this, a lack of socialisation — or poor socialisation — can make a dog become aggressive, mainly when they need to face a difficult or stressful context.
• Possessiveness and resource guarding: this happens when a dog resorts to aggression to protect resources they consider essential for their physical and mental wellbeing. For example, when a dog bites their owner when they try to take something out of their mouth, or possessive dogs who show themselves ready to attack anyone who tries to approach their territory or their loved ones.

What to Do if Your Dog Has Become Aggressive?

You've already taken the first step by deciding to recognise the problem and seek out the information needed to fix it. Now we offer you a brief step-by-step so you know how to carry on acting to help your furry friend.

Make Sure Your Dog Is Healthy

As we saw, there are plenty of health problems that can make your dog become aggressive from feeling more vulnerable and trying to protect themselves from possible threats. Because of this, the first thing you should do is take them to the vet to carry out the proper tests to check their current health, and confirm their vaccination and deworming schedule is up to date.

If you can see a vet specialising in ethology, that would be great, since this professional can help you investigate the cause behind your furry friend's behavioural change, even once any pathological cause has been ruled out.

Start Socialising and Training Them as Soon as Possible

Ideally, a dog's socialisation and training would start during their first months of life, while they're still taking on board their behaviour codes and their character is more flexible. This is the optimal time to teach them the basic rules for living together and the positive behaviours we want our furry friend to keep up throughout their whole life. The more you invest in a puppy's early training and socialisation, the less likely you'll need to correct behavioural problems in an adult dog.

Likewise, you should know it's also possible to socialise adult dogs, although this is a longer, more delicate process, which usually needs supervision from a dog trainer or a professional specialising in behaviour modification.

Teach Your Dog to Drop Objects and Control Their Bite

These two "commands" are usually included among the basic guidelines for canine training and education, but we felt it was worth highlighting them, since they're highly useful for preventing resource guarding and any accident during a play routine, especially when the dog is playing with children, older adults or unfamiliar people.

The "leave it" or "drop it" command will be worked on during training sessions, and will also be key for working on bite inhibition through tug-of-war games, for example.

Give Them Enough Physical Activity

When it comes to physical activity, dogs can have different needs in terms of intensity and frequency, but all of them benefit from regularly exercising. Besides daily walks, we suggest enriching your furry friend's surroundings with toys, games and a range of stimuli that let them stay active and entertained while alone at home.

And if your dog is especially energetic, you can also consider starting them in a canine sport, such as agility, canicross or mushing, for example.

Stimulate Your Furry Friend's Mind

Balanced behaviour in dogs largely depends on proper mental stimulation. A dog who doesn't exercise their sensory and cognitive abilities is far more likely to develop stress symptoms and behavioural problems, including aggression.

In this sense, the best exercise you can offer your furry friend is good training, which, besides teaching them basic canine obedience commands, will also optimise the communication system with you and with every other individual in their surroundings.

An enriched environment will also matter for ensuring good daily mental stimulation, but we suggest setting aside special time every week to offer your furry friend intelligence games.

These have been some basic guidelines for preventing aggression in dogs and other behavioural problems. Lastly, remember that if you don't have the time, patience or knowledge needed to provide your furry friend with proper training, you can always turn to professionals specialising in canine training and education.