It seems like every decade or so, there’s a new breed of dog at the top of the media’s “dangerous” list, followed by a heated discussion over whether breed or environment makes a dog more likely to bite. However, a few characteristics seem to be shared among dogs that are known to bite.
This deep dive into dog biting risk factors will help you understand dog biting behavior and the genetic and environmental conditions that contribute to it. The better you know the causes for dog bites, the better able you are to prevent them.
Which Dogs Bite the Most?
Contrary to popular opinion, study after study proves that context is vastly more important than breed when it comes to how likely a dog is to bite, although biology and genetics can’t be ignored completely.
However, every dog is unique, so even if a dog falls into any of the categories on the below list, it doesn’t mean that it will definitely bite. It just means that the chances are a little higher, so a little extra caution is needed.
Dogs that fall into the following categories have been shown to bite the most:
1. Small Female Dogs
A 2013 study done by the University of Sydney found a significant correlation between aggression and size, with smaller dogs being more reactive overall than larger ones. According to ScienceDirect, small females are more likely to bite than small males.
As of yet, there are no studies that tell us why this is the case, but most experts agree that it is likely due to several factors:
- Small dogs are more fearful, so they feel the need to defend themselves more aggressively.
- Children and other family members more often pick on small dogs.
- Because small dogs are less dangerous, owners are more likely to tolerate aggressive behavior.
- Many owners treat small dogs like babies rather than dogs, failing to properly train and set boundaries.
If you have a small dog at home or are considering getting one, you can drastically reduce the likelihood of bites by:
- Training and setting boundaries
- Making sure the dog feels secure and providing it places to be alone
- Teaching small children in the home not to tease the dog or bother it while it’s sleeping or eating
Although small female dogs are more statistically likely to bite than other dogs, that doesn’t mean that every little female dog is vicious. As you can see in the factors listed above, it’s usually much more a matter of reactivity due to stress rather than due to actual aggression.
2. Unneutered Male Dogs
According to the American Veterinary Medical Association, unneutered male dogs account for up to 76% of reported dog bites. They also make up 90% of dogs who are brought to behaviorists for dominance aggression.
Neutering a dog can lower his aggression towards other dogs and strangers and reduce other hormone-driven behavior such as roaming.
This is one of many reasons why it’s a good idea to neuter your dog, in addition to:
- Preventing unwanted offspring (this is especially important if the dog has inherent aggressive tendencies that shouldn’t be passed down to future generations)
- Eliminating mounting and marking behaviors
It’s important to realize, though, that neutering a dog isn’t going to change his personality completely, and individual temperament and training need to be considered as well.
Neutering is a good first step, but it will only take care of behaviors driven by hormones.
3. Provoked or Startled Dogs
Although most studies focus on severe dog bites, many dog bites are so minor that they don’t even break the skin. Most of the time, these bites are meant to be warnings rather than real aggression and happen when:
- The dog is being teased or petted too hard
- The dog is unable to escape a stressor (such as a loud child)
- The dog is woken suddenly
- The dog is startled by a loud noise or sudden movement
- Someone takes the dog’s food
In the case of startle responses rather than warnings, the bites are usually more a matter of fight-or-flight reactions and are followed immediately by submissive behavior.
Minor bites such as these are the most common dog bites. Although the behavior is generally circumstance-specific and non-threatening, it should be kept a close eye on if it happens regularly, so it doesn’t escalate into dominance aggression.
If a dog initially bites as a reactionary action, there’s always the chance of it becoming a pattern and eventually escalating to unprovoked biting.
4. Overly Territorial Dogs
Territorial dogs want to make sure that uninvited guests stay off what they see as their property. While most dogs have this instinct to a degree, some dogs have stronger territorial tendencies than others.
To drive away perceived invaders, territorial dogs will regularly exhibit behavior such as:
- Barking and growling
- Snapping and biting
- Jumping up at windows and fences
While not all territorial dogs bite, excessive territorial behavior that’s left unchecked will often escalate to aggression, which can lead to the dog biting:
- A guest in the home
- Someone outside the home if the dog escapes
- The dog owner if they try to redirect the dog
Early training and socialization are vital in preventing unwanted territorial behavior. If your dog is excessively territorial and not responding to training, consider getting a dog behaviorist involved.
5. Chained or Tethered Dogs
Dogs who are chained or tethered much of the time are far more likely to bite than are dogs kept in the home. In fact, according to the New Mexico Department of Public Safety, 50% of dog bite fatalities since 1965 were caused by dogs that are kept chained or tethered. Reasons for this are:
- Chained dogs tend to be more isolated and not socialized as well.
- They can’t escape perceived threats, resulting in defensive aggression.
- Chained dogs tend to be more territorial.
- Lack of affection and stimulation leads to frustration and behavioral problems, including aggression.
- Chained dogs are generally unsupervised, so there’s no one to prevent potential bites.
Children who wander within range of a tethered dog are the most common bite victims, although tethered dogs that break free can become aggressive with whoever they encounter.
This is just one of the numerous reasons why keeping a dog tethered for long periods is generally a bad idea. Fortunately, more and more places across the country are banning the tethering of dogs, which should cut down on bites caused by this.
6. Poorly Trained Dogs
It’s not uncommon for dog owners to punish aggressive behavior such as growling. Unfortunately, dogs who are trained not to growl or otherwise warn people away will often bite “without warning.”
Dogs growl to communicate in situations where:
- They’re guarding resources, like food and water
- They want to be left alone, or someone’s getting too close
- They feel threatened or defensive
If the owner punishes the dog for growling, the dog is left without a clear way of warning someone to back off and may resort to snapping or biting to accomplish this.
A better alternative is training using positive reinforcement to desensitize the dog to whatever stimulus is causing him to growl in the first place.
7. Dogs Left Unsupervised
Statistically, children are significantly more likely to be bitten by a dog than adults are, due to many factors like:
- Smaller size
- Likelihood of teasing the dog
- Loud and fast movements that can startle a dog
- Not knowing how to read dog behavior
- Not knowing how to prevent a provoked dog from attacking
Children who are bitten by dogs know the dog 90% of the time, and bites occur more frequently when the child and dog are left unsupervised. The bites may happen more often when there’s not an adult around because:
- The child is more likely to provoke the dog (intentionally or unintentionally).
- The dog feels less secure when the adult isn’t around for protection.
- A dominant dog may feel bolder when unsupervised.
It’s important to teach children from a young age how to safely interact with dogs, teach your dog how to interact with children appropriately, and always supervise them, just in case.
8. Abused or Neglected Dogs
Dogs who suffer abuse and neglect are far more likely than other dogs to develop behavioral issues that lead to biting. The two most dangerous behavioral states that lead to biting are fear and aggression.
Being abused or neglected significantly heightens these two mental states. Fortunately, this doesn’t mean that a dog is beyond training once mistreated, though. Working with a skilled dog behaviorist can help your dog adjust and recover from much of its previous conditioning.
What Makes Dogs More Likely to Bite?
Predicting and explaining dog behavior is no different than doing so with human behavior. We can get a pretty good idea of what an individual will do based on their personality, but that doesn’t mean that they’ll never surprise us by doing something out of character.
Below are some of the most common things that influence whether a dog will bite or not:
Personality and Temperament
As we’ve touched on above, every dog is different and has its own personality.
Genetic components mix with environmental factors early on to decide a dog’s temperament, which will be a good indicator of its future bite risk. If a dog is good-natured and well-trained, there’s a good chance that it won’t bite or that it will bite only when provoked and has no alternative.
A dog brought up in a loving, stable home is far less likely to become aggressive than a dog owned for fighting or protection rather than companionship.
These dogs are rarely socialized properly, causing them to fear people and behave aggressively towards strangers and other dogs. Further, their aggressive behavior is often encouraged by owners who want to make sure the dog will fight when they want them to.
Dogs who suffer from neglect or who must fight with multiple other dogs over food are more likely to exhibit resource guarding behavior. This can lead to biting if someone gets too close while the dog is eating or if you try to take away a bone or toy.
Children in the Home
Over half of all people bitten by dogs are children, with most of them being ages 5-9. As mentioned previously, dogs can be more likely to bite children because:
- They get scared or annoyed by children’s’ loud, erratic behavior.
- Children don’t know how to respect the dog’s boundaries.
- The dog wants to dominate the child due to the child’s small size.
These statistics don’t mean that every dog will bite children, of course, but it’s always a possibility. Fortunately, there are many things you can do to lower the chances, like:
- Teach the child to leave the dog alone when the dog is in certain places, like its bed.
- Teach the child to be calm and quiet around the dog.
- Teach the child to leave the dog alone when the dog is sleeping or eating.
- Supervise all interactions between your child and dog.
As you’ll notice, preventing dog bites in children has much more to do with teaching the child how to avoid provoking the dog than anything else.
Inadequate training can lead to biting behaviors, either intentionally or otherwise.
Some people train their dogs to bite for protection and dogfighting reasons. But there are plenty of people who have no intention of raising their dog’s aggression level but do so out of ignorance.
Common training mistakes that can lead to biting behavior are:
- Not setting boundaries: This can cause the dog to see itself as the pack leader, which may lead to dominance aggression for status reasons.
- Punishing growling and teeth showing: This leaves the dog with no way to warn someone when they need to back off and can lead to biting “out of nowhere” if provoked.
Although punishing a dog for bad behavior is not an efficient way to train a dog, giving a dog free reign over the house can lead to just as many problems.
The key is to use consistent positive reinforcement and nipping the problem in the bud if you spot potential behavioral issues before they become real problems.
Dogs are just as susceptible to behavioral issues caused by disorders as humans are, though it’s only now becoming widely known. The ones that most often lead to biting are:
- Anxiety disorders (low bite inhibition due to constant state of stress)
- Resource guarding (leads to biting around food, bones, and toys)
- Fear-based aggression (often directed at a particular group, such as unknown men)
- Dominance aggression (the dog sees itself as the pack leader and bullies those it sees as in a lower status)
If your dog has a severe or persistent behavioral issue, it’s usually recommended that you consult a dog behaviorist to help retrain the behavior, rather than trying to work with it yourself.
The Truth About Breeds and Biting
Ask anyone what dogs are most likely to bite, and it’s almost guaranteed that they’ll list off the dogs they most often hear about in news reports. Unfortunately, many of the stories people hear are based on incomplete or inaccurate information, which leads to unfair biases against certain breeds.
Here, we’ll work to clear up common misconceptions about what breeds bite the most and where they came from.
The Statistics Are Incomplete
If you look at commonly cited dog bite statistics, the offenders that you’re most likely to see are larger breeds, like:
- German Shepherds
- Pit Bulls
- Bull Mastiffs
However, what people don’t consider is that these studies are reporting only on bites that require medical treatment.
So it makes sense that we only see larger breeds on these lists since small dogs cannot do as much damage. That doesn’t mean that large dogs are any more likely to bite than small dogs, just that their bites can cause injury. The vast majority of dog bites don’t even break the skin, with a full 81% leaving slight or no damage at all.
Since non-injurious dog bites are rarely reported, we have no way of knowing what breeds are doing 81% of the biting; although, according to extensive temperament tests done by the American Temperament Test Society, it’s more likely to be small dogs like chihuahuas.
Note: These tests show pit bulls passing with flying colors, indicating a very low incidence of aggressive tendencies; this is the opposite of what many “dangerous dogs” lists would have you believe.
Media Hype Affects Opinion
When the media regularly reports about how dangerous a specific dog breed is, people are more likely to believe that that’s the case and will more often perceive that breed as more aggressive.
Media bias against certain breeds is nothing new. Just look at the dogs most likely to bite according to previous decades:
- Present: Pit bull
- 1990s: Rottweilers
- 1980s: German shepherds
- 1970s: Doberman pinschers
Anyone who’s lived through more than one of these periods will be able to verify how most headlines featuring dog attacks were focused on that decade’s “dangerous dog.”
A particular breed or breeds making it into the headlines more often doesn’t necessarily mean that they’re any more likely to bite. It may just mean that these incidences are being overreported, and other breeds’ attacks are being ignored.
Misinformation and bias lead to ineffective breed-specific legislation, which does little to actually prevent dog bites.
Problem Breeds Are Unverified
When a dog attack is reported, the officials generally use the victim’s account to determine what kind of dog did the biting. Very rarely do they do the required DNA tests to verify the dog’s breed, and visual identification is often inaccurate, even when done by professionals.
Add bias into the mix, and there’s a high probability of a dog being inaccurately described as a breed that’s commonly thought to be aggressive. For example, ScienceDirect reports that one in three dogs identified as pit bull-type dogs based on visual identification was found to have no pit bull DNA.
This is another reason to take dog bite statistics with a grain of salt since there’s little done to ensure breed identification accuracy in these reports.
Popularity Plays a Part
The American Veterinary Medical Association points out that the number of dog bite incidents per breed can very well have a lot to do with how popular it is in the victim’s community. If a particular species is more prevalent in an area, statistically, it makes sense that there will be more bites from that breed.
The AVMA uses huskies and sled dogs as an example since they’re responsible for a high number of bites in certain parts of Canada. This isn’t because they’re more likely to bite; it’s just because they’re more common to the area.
Although general popularity may increase a breed’s numbers, raising the chances of biting incidents, there’s also a correlation between specific species’ popularity with certain types of people.
For example, a lower-income neighborhood with a high prevalence of criminal activity is more likely to be populated by breeds sought for protection, such as:
- Pit bulls
- German shepherds
If these dogs are treated as working dogs rather than pets, and therefore less likely to be properly socialized, they’re more likely to develop aggressive tendencies. Again, this isn’t because of anything inherent to the breeds, but the environment they’re kept in.
Does Breed Ever Play a Part in Biting?
Although people love to blame certain breeds for biting, the National Animal Control Association says, “Dangerous and/or vicious animals should be labeled as such as a result of their actions or behavior and not because of their breed.”
Dogs’ personalities vary as much as people do, and they should be treated accordingly. Just because a dog breed was bred for a specific reason doesn’t mean it will behave in a certain way.
Just like in humans, the environment plays a massive role in what genetic characteristics are brought out in an individual. For the purpose of this article, let’s take a look at what familiar breeds were originally bred for and the traits that are common to them.
Tiny toy dogs have bred to be companion animals from the start, and they vary widely in disposition, depending on which larger breed they descended from. Examples include:
- Toy poodles
- Yorkshire terriers
Dogs of this size are prone to fear-based aggression and often suffer from separation anxiety.
Although usually harmless, small dogs can be just as vicious as larger breeds, as was proved in 2018 when a pack of dachshunds led to a woman’s fatality. This type of occurrence is rare, of course, but it just goes to prove that larger dogs aren’t necessarily more likely to attack.
Terriers have been bred for centuries for:
- Rat catching
These dogs tend to be super intelligent and energetic but can be snappy with children. This is a broad generalization, though, since there are so many varieties of terrier out there.
Herding breeds were initially bred, and are still used, to herd livestock such as cows and sheep.
Common examples of herding breeds are:
- Shepherds (all varieties)
- Collies (all varieties)
Because these dogs were bred for their prey drive, they can still have predatory tendencies when chasing small animals. They’re susceptible to anxiety, though, which can lead to fear-based aggression.
Examples of guard breeds that have been bred for protection are:
- German shepherds
- Doberman pinschers
These dogs tend to be extremely loyal and respond well to obedience training. They can run on the dominant and possessive side, though, which can lead to unwanted behavior like biting if not trained well.
When most people think of fighting dogs, they think of pit bulls:
- American Pitbull
- American bully
- American Staffordshire terrier
- Staffordshire bull terrier
Pit bulls were originally bred by interbreeding English Bulldogs with various terriers, giving them the strength of bulldogs and the speed and agility common to terrier breeds. Although the dogs were also bred for fighting, pit bulls have always been loyal companion breeds.
Other common fighting dogs are:
- Bull terrier
While dogs with aggressive parents and irresponsible owners may be aggressive towards other dogs, most fighting dogs have excellent scores on temperament tests, revealing them to be much more mellow than many popular “gentle” breeds.
As you can see, numerous factors can increase a dog’s chances of biting, but genetic disposition isn’t a significant one. If you want to know if a dog is likely to bite, you need to look at the dog’s personality as well as its upbringing and environment.