What should I do if my dog is aggressive?

It’s always a worry if your dog or someone else’s appears to be aggressive. It’s important to find out what’s causing this reaction in your dog and help them as soon as possible. Our vets have put together their free guide on dealing with dog aggression.

Dog aggression can be a distressing and frightening problem for dogs and their owners. Some dogs will only be aggressive in specific situations, for example with other dogs or certain people, while for other dogs it may feel like they’re aggressive all the time with no obvious cause or pattern to their behaviour. Whatever the situation, seeing your dog act in an aggressive way can be scary and upsetting, especially as we love our pets and don’t want to see them in a position where they might hurt themselves or others.

It’s easy for owners of dogs who show aggressive behaviours to feel helpless or guilty, but it’s really important to remember that it doesn’t make them a ‘bad dog’ or you a ‘bad owner’. However, it is essential to get help for your dog as soon as you can. Aggression tends to get worse over time and it’s much easier to take steps to help before aggressive behaviour becomes a pattern.


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What causes dog aggression? Why is my dog aggressive?

There are a number of different causes of aggression in dogs but they often start with your dog being afraid. Aggressive behaviours are a natural way for dogs to communicate with each other and they allow your dog to let others know that they’re feeling threatened. Usually dogs will start with subtle signs that they’re scared or try to remove themselves from the situation to avoid a fight. But if this doesn’t work, or they’re unable to get away, they may feel they need to use aggressive behaviour to try to make the scary thing go away.

Over time, your dog may have learnt that being aggressive is more effective for them when they’re frightened than using subtle signs or running away. This can be a big reason why people don’t think their dog is scared. If they’re running towards something and barking or growling, they don’t look scared to us. But your dog may be feeling that their only option is to use aggression.

Most dogs will only become aggressive when they feel they don’t have any other choice. This is why it’s important to try to avoid situations where your dog might behave aggressively and to quickly remove them as soon as they start to feel uncomfortable. Putting your dog in a position where they might become aggressive will likely be distressing for them as well as others and in the worst case, could lead to fights, bites and serious injuries.

Another cause of aggressive behaviours is a dog’s instinct to hunt. Most dogs have some level of ‘prey drive’ (the impulse to run and catch what they see as food). In the domesticated world, these actions can look aggressive to us.

Whatever the cause, it can be really upsetting if your dog shows aggression and can lead to owners becoming concerned about the quality of life for their dog and the safety of themselves and others. The good news is that there are steps you can take to help your dog so the problem doesn’t escalate and lead to further distress or injuries.

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Signs of fear and aggression

Knowing about dog body language is the first step to helping your dog. Dogs rarely bite without warning, but some of the warning signs are very subtle so can be easily missed.

Sadly, some dogs will learn to stop showing these signs if they aren’t being listened to and can move straight to showing more threatening behaviour, so learning early warning signs is one of the best way to avoid aggression.

Subtle warning signs that your dog is feel anxious or uncomfortable include:

  • Yawning
  • Turning their head away
  • Licking their lips
  • Looking away from you and seeing the whites of their eyes
  • Having a tense body
  • Lowering their body
  • Tail tucked under
  • Lifting their front paw
  • Trembling.

Signs of aggression may include:

  • Lifting their lip
  • Staring intently
  • Growling
  • Snarling
  • Snapping
  • Baring teeth
  • Lunging.

If your dog is showing any of these signs, try to remove them from the situation. Never punish your dog for showing these signs or force a dog into situation that’s making them afraid. Telling them off or forcing them into a situation they aren't happy with may cause your dog to act more aggressively and could lead to injuries.

Find out more about your dog's body language in our free guide: 

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What do I do if my dog is aggressive?

If your dog is showing any changes in their behaviour, especially if they have started showing aggression suddenly, you should contact your vet as soon as possible. Aggression tends to get worse over time and can lead to serious injuries to you, your dog or other people and pets so getting help is essential.

Your vet will be able to rule out any medical causes for the change in your dog's behaviour. Some dogs can become aggressive if they are in pain, for example if they are arthritic and have sore joints or a sore back. Your vet will also be able to recommend an accredited behaviourist who can help your dog to cope in the situations that trigger their behaviour and help them learn a better way to react.

Most dogs only act aggressively in certain situations so identifying the cause of their behaviour can really help. If you can avoid their triggers, you will often stop your dog’s aggression getting worse. Discussing these triggers with your vet and behaviourist is a really important part of their treatment.

My dog is aggressive towards other dogs

If your dog is aggressive towards other dogs, the best thing to do is avoid them as much as possible. We know this can be difficult, but try to walk your dog at times or in places when you know there won’t be other dogs around.

If you do meet another dog, it’s best to walk away calmly but quickly. Distract your dog with something they really like, such as a treat or toy, and get far enough away from the other dog that they are calm again. It can help to try to get a physical barrier between the two dogs, for example a gate, fence or car.

Don’t let your dog off the lead in areas where there might be other dogs. Read our advice on dog fights so you’re prepared just in case things escalate.

My dog is aggressive towards people

If your dog is aggressive towards people, it can be more complicated to find the trigger for their aggression. Look for patterns in how your dog reacts:

  • Are they only ever aggressive in a certain room?
  • How do they react around their favourite toys or food?
  • Do they become aggressive when you try to brush them or trim their nails?
  • Do they only act that way towards a specific person or group of people (such as children)?

Once you’ve started to find out why your dog is acting aggressively, avoid the situations that are causing conflict until you can get help from a professional.

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What to avoid when your dog is acting aggressively

Never escalate the situation if your dog is acting aggressively, for example by forcing them to go towards the thing they’re reacting to or by punishing or shouting at them. This can make everything a lot worse for both you and your dog.

If your dog starts to show any of the warning signs above, avoid or stop whatever is triggering their behaviour as soon as possible. If the situation continues or keeps happening, it’s likely your dog will react more and more strongly each time and even the friendliest of dogs can bite if they’re pushed to their limit.

It’s also important to never leave children alone with your dog, especially if they have a history of aggressive or anxious behaviour. Children may not understand the signals your dog is giving and they can act in ways your dog finds unpredictable and scary.

For more information, take a look at our free guide on keeping children safe around dogs:

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Should my dog wear a muzzle?

Dog wearing Baskerville muzzle

No matter how your dog behaves around other dogs and people, it is a good idea to muzzle train them. That way, it will be much less stressful for them if they ever do need to wear one.

There are lots of reasons why your dog might need to wear a muzzle, such as when they need tests or a painful examination at the vets. They can also be useful if your dog has a habit of eating things they shouldn’t when they’re out and about!

Remember, wearing a muzzle doesn’t have to be a bad thing for your dog and it’s better to be prepared in case your dog ever needs to wear one to keep everyone safe.

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What to do if you're bitten by a dog

Knowing and calmly responding to the warning signs above can reduce the risk of a dog biting you. If you’re worried by how a dog is behaving, it’s best to stay calm and slowly walk away. If there's no space to move away then stand still and try not to stare directly at the dog. It’s also a good idea to keep your arms still and out of the way, for example having them crossed in front of your chest. If you or someone you know does get bitten, it’s important to get medical attention as soon as possible.

  • Move away from the dog that has bitten you calmly and quietly. Try not to shout or react aggressively towards them, this might trigger them to bite again.
  • Always contact your doctor or the NHS for advice straight away and tell them that you have been bitten by an animal. If possible, try to clean the wound quickly.
  • Report the bite to the police and local authority’s dog warden so they can take steps to investigate and stop similar incidents happening in future. Taking photos of the wound can be helpful.
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How to prevent dog aggression

There are a few things you can do to help avoid your dog becoming aggressive in different situations:

  • Socialisation. Socialising your dog when they are young is one of the best ways to prevent dog aggression later on. A well-socialised dog is less likely to feel scared and so is less likely to be aggressive towards other dogs.
  • Training. Train your dog with positive, reward-based training. Rewarding them when they stay calm can help them learn that this is a good way to react in the future.
  • Recall. If your dog has good recall, then you can help them avoid potentially dangerous situations by ensuring your dog comes back to you quickly when needed. Remember, you need to keep rewarding your dog throughout their life to make sure they continue to behave in the way you’ve trained them.
  • Staying on the lead. It's always best to keep your dog on a lead in unfamiliar places. This way you always know where they are and can help them avoid anything that might trigger an aggressive reaction, especially if their recall isn't the best. This said, it’s important to remember that a dog on a lead has less of a chance to ‘walk away’ from a situation if they start to find it stressful, so they may be more likely to show signs of discomfort or even aggression if approached by an unfamiliar person or dog.
  • Be aware of other dogs. Never let your dog go bounding up to an unfamiliar dog. As friendly as your dog ay be, you just don't know how they will react. When you see unfamiliar dogs, it's best to keep your dog close to you or on a lead and check with their owner before allowing your dog to approach. This is especially important if the other dog is on a lead, or is wearing a muzzle or has a warning label. These might be signs the other dog is nervous or reactive and you’ll need to keep your dog close to you to avoid any stress.
  • Learn their body language. Know the warning signs of aggression and watch out for them. Never let your dog approach another dog if either of them are displaying any of the warning behaviours or signs of aggression above. If you start to see your dog or another dog behaving aggressively (even if it's not towards your dog) get away from the situation as fast as possible. It’s much better to avoid fights than to stop them once they’ve started. If your dog is playing with another dog, keep an eye on both dogs’ body language at all times and gently lead your dog away if one of them is starting to show any signs of discomfort or unease. Even if your dog has never shown aggression in the past, if either or both dogs start feeling threatened, they may end up fighting.

Learn more about socialisation and training in our free guides: 

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What do I do if my dog is aggressive towards me?

Many people who have experienced dog aggression find that they become afraid of dogs. It can be difficult to know what to do in this situation, especially if it’s your own dog you are afraid of.

At these times, it’s important to know you’re not on your own and there are lots of ways to get help. We would always recommend contacting a professional, like your vet or a behaviourist. They will often be able to provide support and help for you and your dog and discuss the options with you.

It’s also important that you’re supported as dealing with an aggressive dog alone can be stressful, and sometimes even dangerous for you and your family. You could try contacting Blue Cross on their pet behaviour helpline: 0300 777 1975, or Wood Green pet support line: 0300 303 9333. If coping with an aggressive dog is affecting your mental health, you may want to consider contacting the NHS or your GP for advice. Remember that you’re not alone and that there are often way to improve things for you and your dog.

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More about dog behaviour

Their language

Learn all about what your dog is trying to tell you in our free dog body language guide. You'll be able to learn when your dog is feeling happy, stressed or even angry.

Dog body language

Learning the basics

Training is a really important step in helping your dog learn what is expected of them. Take a look at some of our tips on teaching your dog the very basics.

Teaching basic commands

Dogs and children

Sadly, a lot of dog bites involve children. It's really important to teach children how to behave around dogs to make sure everyone stays safe.

Keeping children safe around dogs