Understanding The Aggressive Dog

The media is full of stories about the aggressive dog that has attacked a person, child, or another dog.

We are frequently exposed to the dog fight at the park, even scuffles at the local cafe when a dog sitting quietly is attacked by one walking past.

Dog fights are extremely sad and are becoming far too common.

Questions are often asked and the fault is often placed on a particular breed.

But is it really a breed-specific aggression problem or is the issue about how we are training our dogs?

This is such an emotive subject especially when people are killed or children are harmed.

Many studies have been undertaken to prove whether dog aggressiveness is related to breeding, or if it’s due to other reasons.

The results may just surprise you.

The issue with aggressive dogs is very much a public health and animal welfare issue.

With more than 39% of households owning a dog and there being over 4.2 million pet dogs in Australia, it is essential that we have programs in place that help us to be better dog owners.

We need these programs not only for our sake but for our dogs.

Most Aggressive Dog Breeds

It is very easy to be misled into believing that certain breeds are more aggressive than others.

We’ve all heard the tragic stories of people being horrendously injured or killed.

The majority of dogs that have been at the center of this are often big and powerful.

We need to remember that there are biases attributable to a disproportionate risk of injury associated with larger and/or more physically powerful breeds.

As a vet in practice, I can tell you that there are some very scary chihuahuas out there!

There are some breeds that have been designated as dangerous.

The importation of the following breeds of dog into Australia is prohibited:

  • Dogo Argentino,
  • Fila Brasileiro,
  • Japanese tosa,
  • American pit bull terrier,
  • Perro de Presa Canario or Presa Canario


Each state has it’s own definition of what a restricted breed of dog is defined as. You can find the laws here:







restricted dog breeds in nsw

NSW regulations clearly state breeds that are defined as ‘Restricted’ as well as how a dog may become identified as restricted. Other states have similar laws.

In the US, some states allow insurance companies to deny giving you insurance if you own one of the following blacklisted dog breeds or a cross with one of these breeds:

  • Pit Bull Terriers
  • Staffordshire Terriers
  • Rottweilers
  • German Shepherds
  • Presa Canarios
  • Chows Chows
  • Doberman Pinschers
  • Akitas
  • Wolf-hybrids
  • Mastiffs
  • Cane Corsos
  • Great Danes
  • Alaskan Malamutes
  • Siberian Huskies

Breed-specific bias is, therefore, alive and well, but is this really the problem?

While these might be the most aggressive dog breeds as per an insurance company, is it more appropriate to say that they are the ones that might just inflict the most damage?

Is Breed Restrictive Legislation Working?

The simple answer is no.
All dogs have the potential to bite regardless of its breed.

Risk factors for biting causing serious harm include:

  • the dog’s behaviour/training
  • the dog’s size
  • the number of dogs involved
  • the vulnerability of the person bitten or the other animal attacked
  • how the dog is treated by its owner
  • sex of the dog and neutering status
  • the target i.e. owner vs stranger
  • location of the dog i.e. urban vs rural

As Duffy et al (2008) wrote of their survey-based data: “The substantial within-breed variation…suggests that it is inappropriate to make predictions about a given dog’s propensity for aggressive behaviour based solely on its breed.”

How To Stop Dog Aggression

As we mentioned above, it isn’t the breed of dog that is the problem, it is the environment and how the dog is trained that results in dog aggressive behaviour.

It isn’t the breed of dog that is the problem, it is the environment and how the dog is trained that results in dog aggressive behaviour.

Unfortunately, there have been a few very prominent dog trainers over the years that promote a dominance-based assertive leadership type training that has only made dog behaviour worse.

It is important to try and understand why your dog or what your dog is being aggressive towards before we can begin to work on the behaviour.

canine ladder of aggression

Source: Shepherd K. Ladder of aggression. In: Horwitz D, Mills DS. BSAVA Manual of Canine and Feline Behavioural Medicine, 2nd ed. 2009

Common Types Of Dog Aggression

  • Territorial aggression
  • Competitive (new baby) aggression
  • Possessive (eg. food, toy) aggression
  • Fear-related aggression
  • Idiopathic vicious attacks

Once we understand what triggers the aggression then we can take steps to change the dog’s behaviour.

Treatment Of Dog Aggression

Personal safety and the safety of other people and children must come first.

Please seek professional help from our vets where we can advise what you need to do to keep safe and get a good outcome.

The key aspect of treating dog aggression is to reward good behaviour and ignore every other type of behaviour.

You need to make it very clear to the dog that you as the owner control all things of value: cuddles, food, furniture, toys.

For the dog to get what it wants, it must obey commands. You do not give it what it wants, i.e. a treat, unless it sits.

Start with the easy things first like sit.

Avoid situations that can trigger the issues until you have the basics mastered.

A qualified Delta trainer can assist you with this.

Prevention Of Aggression In Dogs

There are many ways that we as a community can prevent dog aggression.

Much of it comes down to learning how to train our own dogs from a young age, and how to act around other dogs.

We will be covering a lot more of this in the weeks to come.

In the interim, if you have a problem with an aggressive dog contact Your Vet Online for help.  Together we can work to make our community safer. 

Do you have aggressive dogs in your community? Tell us about what you see and what ideas you have to solve these problems. 

Any dog can bite, regardless of its breed, and more often people are bitten by dogs they know.

most aggressive dogs how to stop dog aggression