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No one likes to think their dog could be capable of biting. One of the most common questions most of us get when someone wants to greet our dog is, “Does your dog bite?” If your dog enjoys meeting people you probably tell them that no, your dog doesn’t bite.

But the reality is that under the right circumstances, all dogs can bite.

What that person is really asking is if your dog will bite in reaction to them reaching down to say hello. If your dog likes people, the answer is probably no. That said, it’s important to normalize conversations about your dog’s boundaries and to advocate for your dog by being honest about their temperament. Each dog will have a different threshold for what pushes them to resort to biting, and some dogs will need more support to prevent bites from happening. Knowing the reasons behind why dogs bite will help prevent dog bites from happening.

Why Do Dogs Bite?

With very rare exceptions, dog bites do not come out of nowhere, even if it sometimes seems that way. From small nicks that don’t break the skin to serious bites that require medical care, there are multiple reasons a dog might feel that biting is their best response. Unfortunately, people often miss the warning signs that a bite could happen. Most dogs will try to communicate discomfort prior to biting by barking, growling, or snapping at the air. But what actually leads to dog bites? There are a variety of reasons that dogs might use their teeth to communicate:


Most aggressive behavior from dogs is on some level rooted in fear. A dog might be fearful of something or someone getting close to them, or into their space. When whatever a dog is afraid of gets too close, dogs can become overwhelmed or “over threshold” and may respond by biting. For the dog biting out of fear, it is generally about trying to create distance from whatever or whoever they are worried about.


Dogs can bite if they are startled, especially if they have been sleeping. A dog who is startled awake may be disoriented and confused about where they are and what is going on and might bite. These bites may take people and even the dog by surprise. This can be particularly common with older dogs who may have decreased sight and/or hearing so may be particularly confused if they are startled awake. Always be thoughtful about touching a sleeping dog, and teach children not to crawl into dog beds or wake up dogs who are asleep.

Yorkshire Terrier laying down in its dog bed.
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If your dog has something valuable like toys, food, or chews that they don’t want to share, they may bite out of fear that the valuable thing will be taken away. Biting to protect valuable items can happen as part of resource guarding behavior. Regardless of breed, some dogs may have strong guarding tendencies, and can resort to biting if they perceive their home is being intruded upon, or if they believe someone in their family is in danger (regardless of if that danger is real.)


Dogs can get overwhelmed, which is another situation that can lead to biting behavior. Dogs who feel that they are trapped in a situation that is uncomfortable or unpleasant may bite out of frustration. Dogs can also feel frustrated by being unable to reach something that they want because they are being held back by an owner or leash. Sometimes called redirecting or a redirected bite, dogs in some instances may turn and bite at what or whoever is holding them back.


Being sick or injured can be very stressful, scary, and overwhelming for dogs. Even the most tolerant dogs can bite when they are injured or in pain. If your dog becomes injured, be aware that they may bite when handled so be particularly cautious if you need to lift or move your injured dog. If your dog’s behavior suddenly changes, it’s a good idea to schedule an appointment with your vet as well as with a local positive reinforcement trainer.


One common form of biting that people don’t necessarily think about is mouthing — or biting — which happens in conjunction with play. Light biting or mouthing is a common way that dogs explore the world around them and is a behavior that dogs will engage in during play. While generally not very enjoyable for us, it is a natural part of how dogs play with each other, and of course how they engage with their toys. Watching dogs mouth each other while playing can be alarming. If you are concerned about how mouthy your dog is in play with you or other dogs, setting up a consultation with a trainer can be helpful to help gain understanding about if your dog’s play style is or isn’t appropriate.

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Setting Up For Success

A key way to help prevent dog bites is to remember that dogs are individuals. Not every dog is going to be comfortable in every situation. As a dog owner, it’s important to be aware of your dog’s comfort in different situations. Help your dog be successful by proactively removing your dog from the stressful or overstimulating situation before your dog might feel a need to escalate to biting.

For example, if your dog is nervous about meeting people or dogs, avoid putting your dog into situations where they will be forced or expected to interact with other dogs or people. Not every dog is going to be super social, but by working with a trainer you can learn more about what situations make your dog uncomfortable. Through training, you can gain skills to work within your dog’s comfort level. This will help your dog to work toward developing neutral responses to the presence of other dogs and/or people.

Avoid Flooding/Overwhelming

The goal is to avoid “flooding” your dog with stressful situations. Flooding refers to exposing your dog to prolonged or large amounts of things that scare or overwhelm them. It’s an approach that is generally anxiety-producing for dogs, and doesn’t do anything to shift your dog’s emotional response to the situation they find overwhelming. In these situations, it is more likely your dog will respond to being overwhelmed/overstimulated by biting.

Your dog’s comfort or tolerance for stimulating or stressful situations might shift depending on the degree of stress they are experiencing, how tired they are, as they age, or how unfamiliar a situation might be. For example, if you have a dog who hasn’t had anyone come into the home for the last year and suddenly you have a big birthday party, remember that people suddenly coming into the home could be overwhelming.

Bulldogs greeting on street
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Don’t Punish

If your dog growls, snaps, or even bites you, it can feel tempting to want to punish the behavior. Unfortunately, not only is this confusing to your dog, but it is likely to make the situation worse. A growl or air snap without making contact is a dog’s natural way of warning that they are extremely uncomfortable or overwhelmed by a situation.

If your dog is punished for growling expressing discomfort or displeasure, it’s very possible you will actually increase the likelihood of a dog bite occurring in the future. This is because your dog has learned that they shouldn’t warn (by growling or snapping) and may instead go directly to a bite response when uncomfortable.

Getting Support

Working with an experienced positive reinforcement trainer is always a good idea to get a better idea with understanding both what is normal mouthing behavior and what is cause for concern. Similarly, if your dog has begun lunging, growling, or seems uncomfortable or stressed in different situations, it’s a good time to make contact with a professional dog trainer.

A positive reinforcement trainer will be able to help you with understanding your dog’s behavior, and how to help you to set your dog up for success and avoid putting your dog into situations that are over threshold for them. This might mean giving your dog a safe spot away from the action or avoiding letting your dog off-leash. Your trainer can also help your dog build new associations to situations that are scary, stressful, or overwhelming so that they don’t feel a need to resort to biting.

Related article: 10 Tips for Dog Bite Prevention
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