Desexed dogs – 2.6 times less likely to bite!

Australian Veterinary Association makes this claim, in its PDF “Dangerous Dogs – a sensible solution“:

Entire (undesexed) dogs are 2.6 times more likely to bite than those that are spayed or neutered (desexed)

Are undesexed dogs really that risky?

I decided to read the three studies referenced individually.





Messam, LL, Kass, PH, Chomel, BB, Hart, LA 2008, ‘The human-canine environment: a risk factor for non-play bites?’, Veterinary Journal, 177(2); 205-15.

This study used data from 2003 (11 years ago) collected in Kingston, Jamaica and San Fransico, USA. Participants were recruited from vet clinic waiting rooms where they were presented with a questionnaire, set to determine the nature of their dog’s biting behaviour (and differentiating it from play biting).

When it came to comparing entire and gonadectomised dogs, this research suggests:

  • Intact dogs are more likely to bite than desexed dogs
  • Intact males are 1.68 times more likely to bite than desexed males
  • Intact males were 0.8 times more likely to bite than intact females
  • Spayed females were the ‘least bitey’


Guy, NC, Luescher, UA, Dohoo, Se, Spangler, E, Miller, JB, Dohoo, IR and Bate, LA 2001, ‘Demographic and aggressive characteristics of dogs in general veterinary caseload’, Applied Animal Behaviour Science, vol 74, iss 1. 

This research is based on data collected in Cannada in 1996 (18 years ago), targeting owners with a questionnaire waiting for vet appointments in three Canadian provinces. Their results indicate:

  • The lowest level of aggression (biting and growling) was reported in intact female dogs
  • Intact male dogs were twice as likely to have bitten as intact female dogs
  • Intact male dogs and neutered females incidents of biting was reported at a similar level

And to quote:

“Relative to intact female dogs, neutered male dogs of at least 1 year of age were at the highest risk for having previously shown biting behaviour, followed by neutered female dogs, and intact males… [O]ur results indicate that the behavioural outcomes of [neutering] are worthy of further investigation.”


Gershman, KA, Sacks, JJ & Wright, JC 1994, ‘Which dogs bite? A case-control study of risk factors’, Pediatrics, 93 (6 pt 1), 913-7. 

This study used data from 1991 (23 years ago) using 178 dog bites requiring medical treatment of a non-household-member in Denver, USA. Data was only used for dogs that had not bitten before. The study itself recognises this is a small sample size.

Their data concludes:

  • not-neutered dogs were 2.6 times more likely to bite
  • chained dogs were 2.8 times more likely to bite
  • dogs living with a baby were 3.5 times more likely to bite
  • male dogs were 6.2 times more likely to bite


So, are entire dogs 2.6 times more likely to bite?

If you are looking at the study in Denver, USA, in 1991 (23 years ago!) then, yes, their conclusions indicate that intact dogs are 2.6 times more likely to bite than desexed dogs.

But the other evidence referenced by the AVA does not make the exact same conclusions. The study conducted in 2003, using data from Jamaica and the USA, found that intact males were 1.68 times more likely to bite than castrated males, and 0.8 times as likely to bite as intact females. (This study is also old, with the data being collected 11 years ago.)

And that other article, with data from Canada in 1996 (18 years ago) makes pretty much the opposite conclusion. They found that neutered male dogs were the riskiest in terms of bites.


Questions to ask…

Why are we relying on data over a decade (or two decades) old? If aggression in entire dogs was a common phenomenon, surely we would have countless studies showing this problem.

Where is the Australian data-set?

Where is the study that controls for factors such as selectionsocialisation, and socio-economic factors?


What the AVA should really be saying is:

According to one study conducted in Denver, USA, 23 years ago, entire dogs were found to be 2.6 times more likely to deliver a bite (that required medical treatment) to a stranger than desexed dogs.


Pit Bull Forum on Studio 10

On the 27th of March, Studio 10 had a news article on a boy who was mauled by a ‘pit bull’, but the pit bull was not euthanised, but instead desexed and defanged.

The panel questioned why anyone would have a pit bull when they’re ‘not pets’, and ‘they’re fighting dogs’, with a history of ‘bad accidents’. They criticised public response to this incident saying, “I don’t understand how they’re blaming the babysitter instead of the owner of the dog”.

Paula Abdul is the only one who says anything mildly positive, with “not every part of that breed is bad”.

Understandably, dog lovers were pretty unimpressed with this coverage and criticised Studio 10 through social media.

And Studio 10 then had a ‘right of reply’ panel. And here is how it went down.

While the guise of this discussion was providing balance, Studio 10 clearly pulled the shots, asked the questions, and didn’t provide adequate right-of-reply in many instances. Here’s a blow by blow of what was said… And what I would’ve said.

The little starting introductory video/graphic describes some dog breeds being ‘banned in Australia’, and then describes that in 2011 half of dog attacks were by five breeds (Bull Terriers, Australian Cattle Dogs, American Staffordshire Terriers, German Shepherd Dogs, and Rottweilers). It then goes on to make the claim that bites by restricted breeds are decreasing.

There’s a lot of stuff in this that the expert panel did not get a chance to address!

  • Firstly, no breed is banned in Australia. The five breeds listed are ‘restricted breeds’, meaning that the way they are owned is regulated by most states, but no state outwardly bans them.
  • While we can dispute the validity of the statistics on breed attacks, it should be pointed out that the pit bull terrier does not appear in the list of breeds involved in half of all dog attacks.
  • While bites by restricted breeds may be decreasing (and I’m not even sure if that is true), that doesn’t mean bites overall are decreasing.


Studio 10 asks, “Why do you think pit bulls have such a bad public perception?”

Dr Andrew O’Shea, from the Australasian Veterinary Association, answers this: Because the media chooses to report on pit bull attacks almost exclusively. The media sensationalistness has a lot to answer for. As Dr O’Shea points out, many reports are ‘it’s a pit bull terrier’, when it’s not really. Dr O’Shea points out that the media makes them out to be ‘more dangerous’, but in reality they’re probably just as dangerous as any dog of a similar size. Any dog with teeth can bite.


“But Dr O’Shea, I’m confused though, because the media is reporting we’re told, say by the police and other people at the scene, and I think, there is, like you say, there’s a bit of confusion about talking about pit bulls, er, are the crossed with staffordshire terriers, I mean, I must say, sitting here in the studio, I’m very nervous, I’m, I mean, because of the dogs. I feel frightened.”

Not really a question, nor articulately asked, but then you didn’t give the panel a chance to reply either.

What is significant is not just that the media is reporting on ‘pit bull’ attacks, but the fact that attacks by breeds that are not pit bulls are not reported on. For example, in Port Lincoln an 8 year old boys had his nose bitten off by an Australian bulldog. This barely made the news, and when it did, the report focussed on the death of Ayen Chol by a pit bull. While the news heavily reported on Isabelle Dinoire who received the first face transplant, but neglected to report that her facial injuries were as a result of a labrador mauling.

The fact that you feel frightened is probably a consequence of the media hysteria surrounding pit bulls. I am sorry that you’re fearful, but your fear is illegitimate, and proves that we need to reassess the way dog attacks are perpetuated in the media. When two dogs lay in a relaxed and quiet way in a studio (a totally foreign environment to them), and they are regarded as scary, then the community clearly needs a much more comprehensive understanding of dogs and dog behaviour.


“Centuries ago, they were bred as fighting dogs. Am I right in saying that?”

Dr O’Shea responds to this by basically agreeing, but argues that defining ‘pit bulls’ is complex, and many dogs that look like a pit bull are classified as one despite not being one. And despite being crossbreed. He says that because they’re a bigger breed and tend to be reactive, they seem to get a bad name.

However, I would’ve taken a different response in responding here… I would’ve said:

Yes, but many dogs have roles now vastly different to their original purpose. Many Labradors are bred to assist blind people – while their original purpose was to carry dead birds around. Many German Shepherds are bred for multi-purpose police roles, including biting people, while their original purpose was herding sheep. Many people own terrier breeds who were bred to kill small vermin. Overtime, breed roles change. Additionally, within a breed, there are many variations in terms of personality and type. If you look at the greyhound industry, you’ll see a vast number of greys are killed for not meeting the task at hand, despite breeding specifically for running fast after quarry. You can imagine, in our current era, where dogs are primarily bred as pets, the history of a dog does not have a large implication on the temperament of the dogs we see today.


“A big reactive dog sounds quite scary to me, though. I mean, why, why, what I don’t understand is why people are so passionate about pit bulls in particular. Like, why, I mean, surely, if if, the restrictions at the moment seem to be working at the moment, and the number of attacks is going down, and surely if there is, er, some evidence … For example, you’d be familiar, Dr Hugh Worth, the head of the RSPCA, in 2009 said that there was absolutely no place for these dogs in Australia. He said they were time bombs. He said they should be banned. Now everyone here, I’m sure, who has any knowledge of animal welfare issues knows who Hugh Worth is. He is a very respected veterinarian. The RSPCA is an organisation that is there to prevent the cruelty to animals and protect them. If he is saying it, surely, surely not getting your personal favourite breed of dog is a small price to pay for knowing that kids could be safer. And adults,” say Joe Hildebrand.

“What do you think about that Melanie?” says the host.

Wow, give poor Melanie a chance. There’s about a million points there.

Melanie tries, she says that while ‘the laws appear to be working’ you will probably see that attacks haven’t gone down, but they have stayed the same or risen. She asks if we want to see dog bites to go down, or do we want to see pit bull bites to go down? Maybe pit bull bites are going down, but surely we want dog bites to be going down full stop.

Then Melanie got cut off before she got a chance to say all I would’ve:

  • This is not about people having a dummy spit for not being allowed to own pit bulls. The issue is that banning pit bulls does not make kids and adults safer.
  • There is not a reduction in dog attacks in all, just dog attacks by restricted breeds. So the community isn’t safer from a pit bull ban, they’re just less likely to be bitten by them. (Just like if you banned Ferraris, no more people would die from Ferrari related accidents. But people would still die in car accidents.)
  • Dr Hugh Worth is known as Dr Hugh Worthless by many animal-lovers in Australia. ‘Nough said.
  • The RSPCA is not very well respected and does a pretty poor job at protecting animals.


Joe Hildebrand talks about serious pit bull attacks, and includes footage of a guy severely mauled by three American Staffordshire Terriers. He argues that the severity and frequency of these attacks should see the breed banned.

Again, no real chance of reply is provided. So my reply would include:

  • Hi. The dogs in that video are American Staffordshire Terriers. Not pit bulls.
  • Also, people die from weimaraner and jack russell bites, too. The media often fails to report on these attacks, or when they do so, they report in a different way. (For example, Buster the golden retriever attacked 4 people and the media at the time mostly reported on ‘why would a golden retriever attack?’ instead of the ‘golden retrievers should be banned’ approach we see after bull breed attacks.)

“So you’re not hearing of labradors, or maltese terriers, or toy poodles causing this damage…” says Sarah Harris.

Ambulance guy (from the expert panel) says he’s been to attacks of lots of different breeds. He says that he “can’t tell the breeds apart to be honest” and “In my experience… all dogs can bite. It doesn’t matter what kind of breed it is” and ‘the bigger the dog, the bigger the bite’.

I would elaborate this response, if I had the opportunity, to when you say ‘you’re not hearing of’ attacks by different breeds, that’s because you’re not reporting them


It’s how you train the dog, surely?

Yay, a decent question! Ambulance guy says that he trains his dogs and doesn’t leave them alone with kids. Good advice!


“Brad can talk through how the behaviour works. I mean, are pit bulls aggressive dogs?”

Brad was methodical in his response to this question.

It’s about preventing dog bites. You want the community to be safer, right?

Are you attached to the how (BSL)? Or are you attached to the outcome?

When we look around the world at measures used to reduce dog bite statistics to as low as possible, we see that success is based on behaviour-based strategies and not breed.

“You’ll never get rid of [dog bites] – get rid of 400 breeds – right? It doesn’t really matter.”

Go Brad.


“When we were talking about this last week, a 4 year old boy had been attacked and terribly mauled and there was a question mark over the fate of the dog who did that. And I must say, as a mother, I would want that dog destroyed. I wouldn’t want to be standing up let’s protect this dog because he’s just.. severely injured this child, potentially could’ve killed this child. To me, isn’t that more of the issue?”

Brad answers this one as well.

This is the result of a ‘tragic convergence of errors’.

The dog was chained – chained dogs are more likely to bite.

The babysitter was there – not the owner.

The dog was large – larger dog, larger damage.

The child wasn’t adequately supervised

Well done Brad, again.


Joe Hildebrand wants hands to be raised for anyone who thinks dogs that attack a child should be killed. (That is, he fails to acknowledge the factors affecting the likelihood of a dog bite, as described by Brad.)

There is no place in society for a dangerous dog. What makes a dog dangerous is based upon the behaviour of the individual.


The whole thing got a little bit messy, with Joe Hildebrand speaking over Brad and Brad refusing to be spoken over. In summary:

  • There is a perception in the community that dogs are dangerous and
  • NSW statistics show that the pit bull terrier is the most dangerous breed of dog.

Brad replied that:

  • Perception is only perception, and
  • Those statistics are invalid, and
  • It doesn’t matter: We know what causes dog bites, globally, and we know that BSL doesn’t work.


We were talking about whether a dog who attacked a toddler should be destroyed.

Dr O’Shea says it’s context based. A good call.



And this is where this exchange ends.

So do you think the expert panel was given a fair chance?


Further reading:

A Case Study in Media Bias

Breed Specific Legislation FAQ

Posts tagged BSL on Some Thoughts About Dogs


Are they good with kids?

The common question: Are they good with kids?

What it is really asking is: Does this particular breed bite?

And the answer is: Yes. This breed, and every other breed, bites.


Puppies in a pen with a child peering in.Dog bites are a lot more complex than simple ‘breed’.  Families with children and dogs need to recognise that any child-dog interaction can end up in a bite, regardless of breed.  However, there are a number of ways that dog bite risk can be minimised.

It is very possible for dogs and children to live safely together, but it involves setting the dog and the child up for success, and managing interactions to ensure they are positive.


The Dog

Dogs need to be selected with care as they form an important part of the picture.  For a dog to be ‘good with children’,  they need to be adequately socialised, trained, and have a stable genetic personality and temperament.  Your role, if you’re looking to add a dog to your family, is to select a breeder using stable dogs with good temperaments who socialise their dogs and puppies to all people, including young children.  Once you’ve added one of these well-bred, well-socialised puppies to your family, the next step is to continue to socialise the puppy well with all people, train the puppy appropriate behaviours (e.g. not to jump up), and police child interactions with the dog.

That is, a dog needs to be selected, socialised and trained to be the best dog they can be, and then well managed – for life.


The Child

Children need to be taught to interact appropriately with dogs.  Dogs with stable temperaments should not then be an invitation for children to climb on, poke, or otherwise tease or irritate the dog.  Even good dogs have limits.  Children should be taught to:

  • Always leave dogs alone that are sleeping.
  • Always leave dogs alone that are eating.
  • Always leave the dog alone when they go to their special place (which could be the dog’s crate, bed, or kennel).
  • Always leave dogs along that are acting fearful (and how to identify a dog that is scared).
  • Always leave dogs along that are acting aggressive (and how to identify a dog that is angry).
  • To pat dogs on the chin and chest, and avoid hugging or squeezing a dog.
  • Never do anything that could hurt the dog.
  • Never grab a dog by its collar.

All these interactions are high risk for children, as dogs don’t like being interacted with in these ways, and it may lead to them biting.  Children need to have rules concerning their interactions with all dogs, for their own safety.



As the dog’s owner and child’s parent, you play an important role in managing the interactions that take place between the dog and the child, and ensuring they are appropriate and safe.  For example, it is your job to ensure that children know not to approach a dog that is eating, while also ensuring that the dog is always removed from the children while eating.  If you think your dog may be fearful during a child’s birthday party, perhaps putting the dog in boarding kennels for the weekend or otherwise confining the dog would be an option.  Management also includes alert, conscious supervision of all dog-child interactions: The mantra of “Supervise or Separate”.  If you can’t watch how dog and child are interacting, then separate the dog from the child.

If you know there are deficiencies in your dog’s temperament or your child’s behaviour, then your management attempts should be set up to prevent these deficiencies giving rise to a dog bite.

 A young border terrier sleeping with a child reading the puppy a story.


Any breed that is described as ‘good with kids’ is, at the very least, being deceptively advertised.  Dogs are living individuals, and there’s no guarantee how they will behave with children.

As you can see, the question “Are these dogs good with kids?” is a complex question.  Any dog can be good with kids, provided they are come with a genetic ‘good temperament’ and are well socialised, and well trained.  However, this dog can only be expected to be ‘good’ if the kids interact in respectful and safe ways with the dogs, and all interactions are constantly monitored to ensure all parties are safe.

Having a safe home environment for children is a lot more than just choosing the right breed – it’s an ongoing commitment to education and management of both dogs and children.

If you want your dog to be good with the kids, you really should be asking, “Am I good at management?”


Further reading: See Resources for New Puppy Owners, particularly the links under ‘Children and Dogs’.


The Importance of Bite Inhibition

This post is part of the series in response to Dunbar’s 2012 Australian seminars. See index.

Imagine you are at the dentist and he slips with his little scratchy-hook tool, and stabs your gum a little bit.  You respond by biting down on the dentist’s finger and punching him in the face.

Or you’re asleep in your bed and you partner wakes you as she hops in.  This terrifies you, so you grab your gun from under the mattress, and shoot her.


Red Dobermann puppy chewing person's foot.

Puppies need to be guided to learn to not use the full force of their bite as an adult dog. Photo © Ruthless Photos.

Ian Dunbar used similar human-aggressive examples in his seminar to make a point: Dog-human aggression is never okay.  Just like humans don’t (shouldn’t) hurt people that accidentally hurt them, and don’t hurt people that scare them, dogs shouldn’t hurt people in response to pain or fear.

There are simply no excuses for a dog to be human aggressive – it is never appropriate and never acceptable, regardless of the context.

First, appropriate socialisation should aim to build a confident puppy that is never fearful enough to bite as an adult dog.  Second, a puppy should be taught how to inhibit (i.e. make less forceful) their bite so that, if for some reason they are motivated to bite in their life, the bite is less severe.

Dunbar didn’t go into much detail about teaching bite inhibition at the seminar, but basically the process involves teaching the puppy to bite less forcefully and then teaching the puppy to bite less frequently (and eventually learn that they are not allowed to put their teeth on people).  Alongside this, you add a cue that means ‘let go’.  (It seems that the Dunbar seminar Crystal, at Reactive Champion, attended did talk about teaching bite inhibition in more detail.)

Furthermore, puppies that attend the Dunbar-style puppy classes, with offleash play, mean that they learn how to appropriately control their bite when interacting with other dogs.

The plan is that, after teaching bite inhibition to a puppy, the adult dog will be more likely to bite in an inhibited way.  That is, the depth and seriousness of the bite will be less severe.  A puppy that is well socialised, but does not have bite inhibition, makes for a dangerous dog.


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