Reactive dogs: why it happens and how to help
Is your dog reactive? We can help you to understand what it means, why is happens, and how you can help your dog.

Dogs are often described as reactive if they bark, lunge and pull towards other dogs, people or things outside. Many people think reactive dogs are aggressive dogs, but that’s not always true.
Reactivity can develop when dogs feel:
- worried
- frustrated
- excited
- overwhelmed.
Their behaviour is a noisy and visual expression of how they feel. Over time, their reactions can become learnt habits. The good news is that habits and emotions can be changed. With the right training and support, walkies with your dog can feel better for everyone.
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Quick wins: how to manage reactivity right now
Living with a dog that’s reactive on walks can be emotional and stressful for everyone. You’re not alone. Here are some immediate steps that might help in the moment.
Safety first
- Encourage your dog away from the situation before things escalate.
- If you see a trigger ahead, calmly turn around, change direction or move behind a visual barrier, like a car or fence.
- Keep the lead secure but relaxed. Tension on the lead can make a dog feel trapped and make reactions worse.
Stay calm
- Calmly and quietly keep moving if this helps your dog – stopping can sometimes make things worse.
- Create enough distance for your dog to begin to relax.
- As soon as they relax, give them something they really enjoy like praise, food, or a favourite toy. This gives your dog something to focus on and rewards them for moving away.
- Avoid telling your dog off, as this can increase stress and make the situation worse.
These steps are about managing the moment. Long-term change comes with training and support.
What is reactivity in dogs?
Reactivity in dogs describes a heightened emotional response to something in the environment. This might be another dog, person, object or noise. This isn’t your dog being “naughty” - it’s a sign they’re struggling to cope emotionally. They might be frightened, frustrated, overwhelmed, in pain or unwell.
Reactivity can look different depending on how the individual dog feels and how they’ve learned to cope. For some dogs, this may show as barking, lunging, growling, or snapping. That’s why reactive behaviours are often perceived as aggressive behaviour.
What does reactivity look like?
Behaviour is specific to the individual dog. There are lots of things that influence behaviour and no two dogs will react in the same way. Even the same dog may behave differently on different days.
Reactivity signs
Your dog could be considered reactive on walks if they:
- lunge, bark, growl or snarl at another dog or person
- bounce around frantically, maybe trying to get out of their collar or harness
- grab their lead between their teeth and rag it back and forth
- grab your clothing or body and shake it
- nip another dog they’re being walked with
- try to hide behind you, or between your legs
- try to jump up into your arms
- pull away.
Early warning signs
Reactive and aggressive behaviours rarely happen without warning. Understanding your dog’s body language will help you to recognise how they feel and how they’re likely to behave. Once you know this, you can step in and guide them back to calmness.
If your dog sees something when on a walk that worries, frustrates or overwhelms them, you’re likely to see changes in their body language and facial expressions.
For example:
- first, you might see subtle signs of fear and anxiety like lip-licking, yawning, pulling ears back and turning their head away
- attempts to hide, move away, create space or avoid the situation
- showing they’re no threat by cowering, tucking their tail or rolling onto their back with a tense body
- stiffening, freezing or staring
- no longer taking treats or responding to you
- panting.
After-effects of reactivity
When dogs show reactive behaviours, it’s often a result of an intense emotional reaction. Both you and your dog may experience heightened stress as a result. The effects may be short term or longer term depending on the individual dog and how severe the issue is.
For your dog:
- It can take 48 – 72 hours for the levels of stress hormone to drop in their body. During this time, your dog might be agitated and more sensitive to triggers. Their tolerance for frustration may be lower and there’s a higher likelihood of trigger stacking.
- Increased stress levels, fear and anxiety can make it harder for dogs to relax and settle. They may appear alert or restless.
- Your dog’s confidence may be reduced, needing support to build it back up.
- Even without physical conflict, reactive behaviours like lunging, jumping and spinning, can cause physical injury to both owner and dog. If you’re concerned about injury, please speak to your vet.
- Your dog’s feelings and reactions could get stronger over time. For example, if they acted out of fear, the situation could reinforce that there’s something to be afraid of.
- The more your dog practises reactive behaviour, the more likely they are to use this response again – especially if their behaviour was successful.
Call us for expert advice on 0303 003 6666 for your dog’s behaviour and ongoing support to help you resolve concerns.
For you:
- In the short term, you might feel stress, embarrassment and worry for all concerned.
- Over time, constant stress, anxiety and the fear of judgement from others can take a heavy toll. Managing reactivity is draining and, when incidents happen, feelings of shame and failure are common-even when you’re doing your best.
- Lifestyle changes like walking at anti-social hours and in remote places can lead to feeling isolated.
- You might feel sad and grieve the ‘normal life’ you’d hoped you’d have with your dog. This can lead to feelings of resentment towards your dog and feelings of guilt.
If you, your dog, or someone you know has been affected by aggressive or reactive dog behaviour, please don’t struggle alone. It’s important to reach out for help for your wellbeing, as well as your dog’s. Talk with family, friends and professionals like your GP or charities like Mind and the Samaritans.
- Call Mind on: 0300 102 1234
- Call Samaritans for free on: 116 123.
Positive outcomes:
It may seem odd that there can be positive outcomes from unwanted behaviours. But, thankfully, there are.
- Increased knowledge. Caring for a reactive dog is an opportunity to learn new things and grow alongside them. While the learning curves are steep, they are rich in knowledge that can help both you and your dog in future.
- The wins are huge. There are many challenges living with a reactive dog. Training plans can take time and setbacks can be upsetting. When you make progress though, few things are more rewarding.
- Stronger bonds. With the right support, reactivity can be significantly improved. Each step forward on your reactive dog training journey will feel amazing. But the bonds strengthened by taking this journey together last a lifetime.
Why dogs become reactive
How to help a reactive or aggressive dog
Dog reactivity can be challenging to live with. It can cause deep upset to us, and a lot of stress for our dogs. We always recommend seeking support from your vet and a clinical behaviourist for help with resolving aggression or reactivity. There are three key steps when managing reactive behaviour in dogs:
- 1
Understand your dog
Dog body language quizLearn to recognise how your dog’s feeling by reading their body language and facial expressions.
- 2
Identify triggers
Work out what your dog reacts to and in what situations. Keeping a diary of interactions and incidents can help you spot patterns.
- 3
Avoid triggers
Where possible, avoid situations that make your dog react or use aggressive behaviours. This helps keep everyone safe and prevents them from practising these behaviours. It’s unrealistic to avoid triggers completely. But thoughtful management can reduce stress and support your...Show detailsWhere possible, avoid situations that make your dog react or use aggressive behaviours. This helps keep everyone safe and prevents them from practising these behaviours. It’s unrealistic to avoid triggers completely. But thoughtful management can reduce stress and support your dog while you work on longer-term training.
Longer term
To help change the way your dog feels, you need to pair the triggers (e.g. dogs or people) with positive feelings. This can be achieved by rewarding them for seeing people or dogs and remaining calm.
This needs to be carefully managed at a distance your dog can cope with, so is best done under the guidance of a qualified professional. Our expert teams can support you with this, so get in touch today.
It’s important to recognise that under the Dangerous Dogs Act 1991, it’s against the law to let a dog be dangerously out of control. This applies in public and in private. For example, a park, your home, or a neighbour’s house. This section of the law is not breed specific and applies to all dogs.
Managing triggers out and about
Here are some ideas to manage your environment and avoid triggers out and about:
- Keep your dog on a lead or a longline to prevent them from running off and getting into trouble.
- Walk in quieter places and at quieter times. For example, an industrial estate after hours. Places where dogs are not allowed to be off lead will limit the risk of dogs suddenly appearing. Avoid taking narrow paths. For example, canal towpaths.
- Try to walk in places where you have good visibility for a long way so you can see if anything’s coming. Bonus points for lots of exits.
- Bring small, tasty treats with you on walks. Reward your dog for any positive behaviours they show. For example, paying you attention and walking nicely on lead or seeing a person or dog in the distance and remaining calm.
- Use trees, parked cars and other stationary items to block your dog’s view of a trigger.
- Help your dog by giving others a wide berth if you spot someone approaching. For example, by crossing over the road, if safe, or changing direction. Try to do this before your dog starts to react.
- Encourage your dog to move away with treats, praise, toys and positive encouragement.
- Advocate for your dog. Don’t agree to them being stroked if you know they don’t like it. Ask owners to call their dog back if it’s off lead and worrying yours. It doesn’t always feel natural to do, but it can avoid a negative interaction.
- Consider hiring a secure ‘dog field’ so your dog can burn energy and exercise off-lead, without the risk of coming across other dogs or people.
- Consider muzzle training your dog as an additional safety measure.
- If you have more than one dog, it can be easier and safer to walk them separately.
Daily habits that make a difference
- Consistently use reward-based training methods. Avoid any training methods that use fear, intimidation or pain which could decrease your dog’s confidence.
- Reward calm behaviour when you see it. Especially if your dog is calm and quiet when you’d expect them to be reactive.
- Allow choice. Ensure your dog can move away from things they’re worried about. Making them “face their fear” could make matters worse.
- Take your dog to the vet to rule out underlying medical conditions.
- Seek support. In cases of aggressive behaviour, it’s important to get expert help. Get free, qualified advice from our friendly Behaviour Support Line team. For more in-depth support, our Behaviour Coaches and Clinical Behaviourists are ready to help.
- Ensure your dog’s needs are met. If a dog’s needs for mental and physical stimulation are not met, there is a risk of them becoming frustrated. This increases the likelihood of reactivity.
- Stick to routine. Dogs do best when they know what to expect and when. Consistent and predictable schedules help them to feel safer.
- Advocate. Be your dog’s advocate and speak up when they’re worried. For example, saying no to people who want to stroke them if they’re not relaxed.
- Reduce stress. Allow your dog time to de-stress as needed. This might mean having a day or two with more enrichment, play and napping. Especially if they’ve had a challenging day.
- Plan your route ahead of time to ensure that paths are wide, exits plentiful and that you have good visibility to see triggers coming. Visiting areas without your dog before you take them there can help, especially if you go at different times of the day. This can help to know when bin day is, for example, or at what time the post tends to come.
- Stay calm. If conflict occurs, avoid telling your dog off as this could make things worse. Aim to be reassuring, steady and gentle instead of tense, sudden and loud.
- Practise focus training with your dog to encourage them to pay attention to you on walks.
- Practise engagement games like “find it” to build confidence and provide distractions during walks.
How to teach 'find it'
- 1
Introduce the cue
Scatter a handful of treats in the home, saying “find it” as you do. The aim is that your dog will put their nose to the ground and sniff them out.
- 2
Repeat
After repeating this game a few times, your dog will soon start putting their nose to the ground as soon as they hear you say “find it”.
- 3
Practise outside
You can then practise in your garden and in quieter areas outside the house. Eventually, you can try when there’s a dog or person in the distance.
- 4
Try it on a walk
The idea is that you can then use this to distract your dog as another dog or person approaches. Them sniffing about gives a clear sign to other dogs that they’re busy and don’t want to interact. And you’ll have time to decide which way to turn to best avoid the interaction....Show detailsThe idea is that you can then use this to distract your dog as another dog or person approaches. Them sniffing about gives a clear sign to other dogs that they’re busy and don’t want to interact. And you’ll have time to decide which way to turn to best avoid the interaction. Your dog will also have an activity to enjoy.
- 5
Keep practising
Remember to keep practising this game at home and on quiet walks, even when there are no dogs or people around. Otherwise, your dog might learn that “find it” means a trigger is nearby and look up for the other dog rather than down for their treats. This would be...Show detailsRemember to keep practising this game at home and on quiet walks, even when there are no dogs or people around. Otherwise, your dog might learn that “find it” means a trigger is nearby and look up for the other dog rather than down for their treats. This would be counter-productive.
Building confidence over time
Some dogs are naturally more confident than others. Lots of things can influence how confident they feel. For example, what they have or haven’t experienced in life. Dogs that have lower confidence may find life more difficult, so it’s important to help them overcome their anxieties.
Tips to build confidence in your dog:
- Understand their body language and signs of anxiety. This will help you work out what scares them so you can respond appropriately.
- Keep your distance. The further away you are from the thing that worries your dog, the easier they’ll find it to cope.
- Keep walks short and fill the day with the things they love the most, like enrichment. In the short term, this is better than longer walks with more exposure to triggers.
- Make sure to add fun activities to the walks you do have. For example, gently playing tug when out or using enrichment like a snuffle mat when you arrive.
- Give your dog opportunities to de-stress with lots of time for rest at home. Especially if they had a challenging day the day before.
- Be your dog’s advocate. Encourage them to move away from what worries them and decline interactions if other humans or dogs bother them.
- Allow them the choice to end interactions, even with you.
- Most importantly, celebrate those wins. Even the small stuff. Praise and reward them when they’re brave or investigate things.
- Never force an interaction. This includes coaxing them with a treat into a scary situation. There’s a risk that your dog suddenly realises what’s happening and tries to defend themself.
- Go at your dog’s pace. They will grow in confidence more quickly this way.
- Using reward-based training isn’t just the most effective way to train according to science. It’s also a great way to build confidence. Being rewarded for making the right choices helps dogs to feel more confident in their abilities.
- Avoid punishment-based training methods or methods that use fear and intimidation. This is likely to make your dog feel worse. Equally, avoid making your dog ‘face their fear’. This can also make the situation worse.
Tools and equipment
Believe it or not, what your dog wears out and about can really make a difference to their behaviour.
Here are our top tips:
- Make sure all equipment is the right size, shape and fitted correctly. If it’s too tight, it could cause tension or pain, making things worse. Too loose and it could lead to an escape.
- For maximum support and comfort, consider a Y shaped, fixed-size harness.
- A harness with two points of contact (with a D ring on the back and another on the front) can give the user extra control. You’ll need a double-ended clip lead.
- A long-line can be helpful for allowing your dog to have a bit more freedom without being off-lead and potentially unsafe. They must always be attached to a harness.
- Muzzles are useful for dogs that might lunge or use aggressive behaviours. A basket muzzle will allow your dog to pant, take treats, drink and exercise. A muzzle can give you peace of mind and act as a visual signal to others to give your dog space. However, a muzzle won't change the way your dog feels about a particular situation or trigger. Even with a muzzle on, it’s important to try to avoid situations that make your dog feel worried. A qualified behaviourist will be able to support you in changing the way your dog feels.
- Make sure your dog is always wearing a collar and ID tag in public and that microchip details are kept up to date. This is law in the UK.
Don’t forget that using new equipment means that you need to train your dog to help them feel relaxed and comfortable in it. If they’re worried about the equipment, they’re more likely to be reactive.

How to train your dog to wear a muzzle

How to train your dog to wear a harness
What not to do with a reactive dog
- Avoid telling your reactive dog off. They may become more afraid of the trigger, which could intensify their behaviour. It can damage your bond as they may become worried of you as well as the trigger. If you tell your dog off for growling, they may stop, but will still be scared. This effectively removes your warning system that something is wrong. They might feel they have no option but to lunge and bite next time.
- Avoid triggers where possible. The more a dog practises reactive behaviour, the more likely it is for the behaviour to become a default response.
- Don’t force interactions. This is likely to overwhelm your dog and others and increases the likelihood of an incident happening. Behaviour change needs to happen at the pace of the individual.
Common triggers for reactive behaviour
How to prevent your puppy from becoming reactive
If you have a new puppy, the best way to tackle reactivity is to prevent it from happening. You can do this by carefully and positively introducing your puppy to things they’ll experience throughout life. This could be:
- people
- dogs
- other animals
- veterinary practices
- groomers
- traffic
- noises
- different objects, surfaces and smells
- a variety of experiences.
This will give them the best chance of coping well and feeling confident in various situations as they get older. The best time to do this is during the first four months of your puppy’s life. This is called the socialisation window and is when dogs learn what’s normal and safe in their lives.
Our puppy socialisation advice has lots of tips and tricks to help you develop your puppy into a confident and resilient dog. Here’s a quick overview of things to consider:
- experiences should be introduced gradually and in a calm manner
- aim for positive or neutral experiences when your puppy is relaxed
- stop immediately if they become worried, scared or overwhelmed.
The Animal Behaviour and Training Council (ABTC) is a good place to look for puppy classes and dog trainers.
When to seek professional help
Vet check
It’s important to rule out any underlying health conditions at the onset of reactive or aggressive behaviour. This is because health and pain have such strong influences on dog behaviour. Pain and medical issues can leave dogs with a lower tolerance of others and a reduced ability to cope.
Even when there are no obvious signs of pain or illness. Some medical issues are subtle, develop gradually, or are masked by dogs coping well, so even very attentive owners may not notice anything wrong. You should seek veterinary advice if your dog has suddenly started reacting when they didn’t before, or you have noticed a change in their behaviour.
A visit to your vet is a supportive first step. It could rule out any medical causes or fix the behaviour. Knowing your dog is healthy will make any behaviour support and training clearer, fairer, and more effective for you and your dog.
To help your vet assess your dog's behaviour, it can be helpful to bring along any videos, diaries or notes you have to your appointment at the vets. Speak to your vet when booking if you think it'd be useful to have a detailed conversation before the physical exam.
Behaviourist support
We understand how stressful it can be when your dog is reactive. Even well-planned walks can have surprise encounters that feel like major setbacks. We’re here for you, and your dog.
Contact our Behaviour Support Line, request a call back from an expert, or book a support package now. We help thousands of dog owners, just like you, with judgement-free advice every year. Our team can offer a wide range of support depending on what you feel is best for you – even if it's just to check you're on the right track.
Real owner stories: you’re not alone
Tracey called our Behaviour Support Line when her Golden Retriever, Lilly, was struggling with reactivity.
"I was extremely impressed with the behaviour support line. They listened to my concerns with understanding and empathy, were really reassuring, and gave me practical advice straight away. They were very knowledgeable and talked me through some considerations and options."
I honestly don't know what I would have done without the support of the training team. Thank you so much!
Tracey, Lily owner
Contact our behaviour services
Whether you’re facing a tricky behaviour or feeling completely overwhelmed, we’re here to help. Our team of experts can offer advice, training and support.
Call us on 0303 003 6666
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