Dog aggression is a serious behavioural issue that is one of the main reasons owners seek professional help from trainers, behaviourists and vets. It can range in severity from low-level growling to barking and biting and can have a large number of potential triggers. It is a common misconception that only certain breeds can be aggressive; this is simply not true. Any dog, large or small, is capable of being aggressive.

Where does it come from?

For most wild animals, aggression is a fundamental behaviour that exists to protect them in a multitude of circumstances. Dogs originally used aggressive behaviour to defend territory, obtain and protect food, protect their sexual partners and family as well as fighting for their hierarchical position in the pack. Therefore aggression is something that has been present in animals for a very long time. Whilst dogs are now domesticated, there are still instincts that exist which could perhaps trigger aggressive reactions. It is our job as owners, to curb this aggression as soon as possible and train our dogs to understand the correct way to act to avoid acting in this aggressive manner.

Why do some dogs develop aggression

There are many different opinions on why a dog may be aggressive. One commonly used explanation is genetics and breeding. Different breeds have been used throughout history for different jobs, such as hunting, protecting, herding, retrieving etc. This means that each breed has unique characteristics to suit their purpose. Hence some dogs can be more likely to develop aggressive tendencies. This does not mean that some breeds are going to be aggressive and others I’ll alk be docile. This is a very common misunderstanding that unfortunately gets widespread broadcast, meaning many breeds get unfairly labelled as aggressive without justification. Obviously certain breeds are more likely to react aggressively in certain circumstances, just as some breeds may be more likely to protect their family. However, all dogs, no matter their breed, can be aggressive.

One of the main reasons for dogs developing aggression is a lack of exposure and proper socialisation early in their lives. This is particularly important with breeds that are genetically more likely to have aggressive tendencies. Providing a dog with proper socialisation is minimalising the chance of this aggressive behaviour coming out. Without proper exposure and socialisation you are setting your dog up for failure. Young dogs are like sponges. They soak everything up. Dogs need to have the opportunity to experience everything life will throw them, all whilst knowing it’s safe and fine.

Types of aggression


This is the most common type of aggression and accounts for approximately 93% of all dogs that show aggression. It is one of the main reasons dogs are euthanised yearly. This aggression can be caused by fear of other dogs or people and is often due to lack of exposure in the first 16 weeks of a puppy’s life. Having said that fear can also be genetic and passed down from the mother or father so make sure you see the parents before buying a puppy.


This aggression can often be referred to as protective and stems from a dog’s natural instinct to protect their territory. It is often related to fear rather than dominance. If a dog displays aggressive behaviour towards strangers or dogs only on home turf – or near home – but does not display this on neutral territory, then this aggression is likely to be territorial. The two primary motivators for this aggressive behaviour are dominance or fear.


This behaviour is usually limited to male dogs that have not been castrated. This behaviour will often be displayed by the dog mounting both dogs and people. This can be related to control and dominant behaviour; often dogs will try to put their heads over the other dog’s neck and then attempt to mount them, showing rank over another dog. If this sexual behaviour because uncontrollable then some recommend castration, however, this can have a lot of adverse effects and can actually increase the aggression.


Redirected aggression is when a dog is acting aggressively and this aggressive gets redirected onto something else. For instance, if two dogs are fighting and an owner tries to separate them then the dogs can redirect and act aggressively towards the owner, even though this was not the trigger for the aggression initially,


This aggression can be towards both people and dogs but is more commonly aimed at dogs. It can stem from attempts to assert authority and obtain control. A common training approach which is effective with dominant aggressive dogs is the NILIF – Nothing in Life is Free. This approach means dogs work for everything they want and need in life. This gives a dog purpose as well as a job to do.


This can be directed at many different things including cats, birds, squirrels and many other things. In essence, it is anything that stimulates a natural chase response. Something that distinguishes this type of aggression is that movement is often the trigger. With some breeds this aggression can even be triggered by movements such as runners, bikers, rollerskaters etc. This aggression is often very difficult to train out of a dog as it is deeply engrained in their predatory instincts, however, consistent training from a professional can resolve the behaviour to a controllable level.


Possessive aggression can be directed towards people or other pets that approach the dog when they are in possession of something they view as highly desirable. This can be a favourite toy, chew or food.


This aggression is something that female dogs sometimes experience when they have puppies. It is an instinctive behaviour that comes from the desire to protect her babies and can be directed at any person or dog that she fears may jeopardise the safety of her litter.


Aggression as a result of fear something that even the most placid dogs can show at some point in their lives. When a dog is in pain it can react aggressively; this can be due to them trying to avoid the pain getting any worse or them reacting adversely because of the pain they are in. Often dogs in severe pain may need to be muzzled when going to a vet as their normal calm temperament may not be displayed when they are in such uncomfort.

Is your dog showing any sort of aggression than please get in touch with us!