reactive dog on leash barking at nervous dog

Dog Reactivity: Causes and Solutions

Understanding Dog Reactivity Dogs can display a behavior known as reactivity, which is when they have a strong and negative response to certain stimuli or “triggers” in their environment. Reactive behaviors can include barking, whining, spinning, growling, lunging, snapping, or aggressive behavior when exposed to specific situations, people, animals, or objects. Typically, reactive behavior is linked to fear, anxiety, or overstimulation.

Common triggers for dog reactivity include other dogs, unfamiliar people, loud noises, bicycles, vehicles, or any situation that the dog finds threatening or overwhelming. Reactivity can manifest on or off-leash and may vary in intensity from mild to severe. It’s essential to address dog reactivity through training and behavior modification techniques to help the dog become more comfortable and less reactive in these triggering situations. Positive reinforcement methods, desensitization, and counterconditioning are often used to manage and reduce reactivity while promoting calm and appropriate responses.

The Two Most Common Reasons for Reactivity

Dogs can react differently to stimuli, and it’s important to understand the underlying factors that contribute to their reactions. Here are two scenarios that can affect a dog’s response to stimuli:

  • Over-arousal, excitement, and eagerness to approach the “trigger” combined with restraint by a leash or barrier like a fence or window which causes frustration. The reactive dog in this scenario wants to decrease the distance to the stimulus.
  • A fearful or anxious response due to a lack of history of positive associations with a particular stimulus or a previous negative experience with one. The motivation for this reactive dog is to increase distance from the stimulus, i.e. (dog or person).

How This Happens

For instance, some owners limit their puppy’s exposure to novel stimuli such as cars, other dogs, sounds, new people, gardeners, bikes, and skateboards before 16 weeks. This is often the advice of veterinarians who typically do not appreciate the importance of proper socialization. Their concern is mostly concerning infectious diseases like parvo or distemper. (You can safely socialize before all your shots) This can present a challenge for the puppy, who is more receptive to novel stimuli between 8-14 weeks of age. Keeping your puppy safely in your home/yard until 16 weeks is similar to keeping your children out of preschool and kindergarten and expecting them to adapt to 1st grade without being overexcited or nervous for some time. (See also, Behavior Problems with Covid Puppies.)

A fearful or anxious response due to a lack of history of positive associations with a particular stimulus or a previous negative experience with one. The motivation for this dog is to increase distance from the stimulus, i.e. (dog or person).

On the other hand, some owners expose their puppies to too much stimuli, taking them everywhere and allowing anyone to touch them. This can cause sensitization to these stimuli, which is a common reason a puppy might start reacting negatively towards things or places they were comfortable with before.

What is Socialization.

Simply put, it the process of exposing a puppy to novel stimuli in order to establish a neutral association with it. This is most effective long before your vet will suggest you take your dog for a walk. The crucial period of socialization is from 4-14 weeks. This is when you will have the most impact with respect to teaching your dog how to feel around a variety of situations and events in the future. Owners who try this after 16 weeks, will likely have a much harder time with behavior changes in adolescence, (6 months – 2 years) This is when the majority of reactive behavior starts.

Under and Oversocialization problems

I can not stress the importance of proper and adequate socialization for puppies. One of the most likely culprits for encouraging reactivity in dogs is a lack of careful exposure to novel stimuli during the socialization window prior to 14 weeks.

Please also see the AVSAB (American Veterinary Society of Animal Behavior) position statement on puppy socialization.

Contributing Factors for reactivity: Genetics, and Epigenetics, and Pain

There is an overwhelming amount of evidence supporting genetics and epigenetics as two huge factors in the temperament, resilience and behaviors of your puppy or dog. The DNA passed down to your dog from its parents and their grandparents,who have there own behavior issues and personal experiences matter a lot when it comes to how your dog behaves. The genes your dog has are complex and are the recipe for behavior ongoing. The environment while your puppy or dog was in utero and after birth up to the time you get them, epigenetically determines how those genes perform and respond to conditions in the future.

This means that the conditions surrounding the birth of your dog matter a lot. Was your puppy imported or found on the side of a road? Did the mom have shelter and proper nutrition during her pregnancy? Were the puppies born inside or outside? What type of stimulation was available from birth to 8 weeks? These are all factors that matter for brain development and setting your dog up for success. While nothing is guaranteed, it should be expected that dogs who had a more challenging time during these stages of life will have some challenges in the future. For instance confidence issues (pessimism vs. optimism), arousal regulation and impulse control, as well being more fearful and apprehensive all contribute to dog reactivity in the future.


Pain is a huge contributing factor affecting mood and behavior such as aggression. As many as half of aggression cases also have a diagnosis of pain or inflammatory issues. Common sources of pain and discomfort are: Skin allergies, osteoarthritis, nerve pain, digestive issues, ear infections, breathing issues affecting brachycephalic dogs, soft tissue injuries from playing, jumping, turning, and sliding on slippery floors.


As I mentioned earlier, the majority of reactivity cases I work with are with adolescent dogs. This is no coincidence. The adolescent brain is a mess and essentially under construction from 6 months -2 years and even longer for larger breed dogs like mastifs, danes, etc.

To start, your dog’s prefrontal cortex, the part of the brain responsible for executive functions, which include planning, decision making, impulse control, and concentration. This is part of the frontal lobe, which which is part of the cerebral cortex, and is associated with higher cognitive processes such as problem-solving, memory, and social interaction.

Complications that can arise from the canine prefrontal cortex during adolescence include:

Impulsivity: Adolescence is a time when dogs may exhibit more impulsive behavior, often acting without prior thought, which can be attributed to ongoing brain development.

Difficulty with Training: Adolescents may challenge training commands they previously mastered, not necessarily due to a lack of understanding, but as a part of testing boundaries and exerting independence.

Increased Reactivity: Dogs may become more reactive to stimuli in their environment, sometimes leading to behaviors such as barking, lunging, or showing fearfulness that weren’t previously evident.

Social Navigation: As they mature, adolescent dogs are also figuring out their social standing and how to interact appropriately with other dogs and humans. This can result in awkward or aggressive social interactions if not guided properly.

Attention Span: Adolescents might display a shorter attention span for tasks they find less rewarding or engaging, making consistent training more challenging.

Hormonal Changes: Just like humans, hormonal changes can affect a dog’s behavior, which may lead to increased aggression, fear, or marking behaviors.

This should make it clear your adolescent dog is mostly having a hard time and not being purely defiant, dominant, alpha or spiteful. Switching to dominance or correction based training here can really make your dog’s life harder. Know that it will get better with time. Having said this, there is still a need to help these dogs relax, learn new behaviors and feel more confident. They need the right approach which usually involves patience and understanding first, followed by consistency and accountability on the owners

Recommendations for Reducing Reactivity in Dogs

It’s first recommended to avoid the use of aversive training tools that may cause the animal more stress, discomfort or pain. Such tools include choke chains, pinch or prong collars, and electric collars. Instead, a comfortable front clip harness is suggested as a preferable alternative. Specifically, the Balance Harness is highly recommended as it provides an optimal fit, doesn’t obstruct the trachea/larynx, and features a front clip that is more effective than most other brands.

For dogs who are fearful we want to desensitize them and teach them that they can walk away or engage with the owner/environment to feel better about scary/unpredictable situations. (appearance or approach of a dog/person)

First things first! NO Tightening of the leash when you see a dog on a walk. Don’t signal them to be on-guard. Wait for them to see the dog and initiate one of the following games.

Establishing Predictable Games to reduce Dog Reactivity

Before attempting to train your dog in real-life situations, try establishing a few pattern games to help them learn the ropes. These games provide a predictable routine that can make your overwhelmed or scared dog feel more secure. They can be especially helpful for dogs that tend to bark, lunge, or growl when they don’t know what to do. Initiating one of these games can often get your dog unstuck with a trigger present.

  • Pattern Game 1 Up – Down Game.

The Up/Down Game is a simple way to train attention and build a predictive pattern that is easy to initiate in difficult or distracting environments.  Simply have your dog on leash in your home without distractions and say their name. When they look up to your eyes, say Yes! with a quick and upbeat tone. Feed them a yummy treat on the ground, let them eat it and when they look up again, say yes and continue the pattern of putting the treat on the ground to reset their gaze. Repeat this 20 + times a few times a day.

Next Name the behavior, Look!

When your dog is predictably looking up to you each time, say look! Just before they are about to raise their head. Say yes, and feed your dog to the floor/ground after the look. Keep saying look and rewarding to the floor until your dog loves the word look and can respond when you say the cue the next time.

To make it more fun after they look at you, toss the treat a few feet away and see if you get the same response. Practice this is several different environments to generalize the behavior. You don’t want this to only work in your living room.

  • Pattern Game 2 – Touch and Toss 

Sit in a chair with plenty of treat or food in a pouch or on a table next to you. See youtube video. Have your dog sit in front of you facing you. Show your dog your flat empty flat palm ( fingers facing down), about 2-3 inches from their nose, and if they come closer to it or especially touch it with their nose, say yes and give them a reward by tossing it on the ground about 3 feet away. Repeat this drill for about 10-15 repetitions with both hands. Make sure once your dog is on their way back you put your empty hand out for them to touch again with their nose. This is nose targeting. Your dog is learning a fun skill that has them focus on a part of you, similar to looking at your eyes but just your hand.

Increase Difficulty 

Once your dog is readily coming back to touch your hand, add movement. Stand up and walk away from your dog a few steps with your empty hand in front of you. If you dog follows you and touches the hand, say yes!, and toss a treat on the ground again about 3 feet away. Once your dog is reliably touching your hand in these contexts you can name it “touch”. Just say the word touch, then present the hand. This will teach them the new word has means touch come to your hand. This is a great game to practice on walks. Start this without dogs present and then try around distractions after some successful practice.

3. Scatter Feeding

Once your dog perks up when you say FIND IT! , you can try it around distractions. When a new person or dog appears, say Find-it! And toss 5-10 treats to the ground. Watch your dog ignore the person or dog. This should be executed once your dog sees the distraction so they think the stimulus (person or dog) had something to do with the fun game. Be careful not to say “FIND IT” to your reactive dog if they haven’t seen the trigger / distraction. This error can sometimes make the treats preceding the trigger become untrustworthy or predictive of something negative. Order matters here. Pro Tip: Keep extra distance from the triggers for a while. Distance makes it easier.

reactive dog in harness looking for treats in grass after scatter feeding

4. Get out of Dodge cue. (U-turn cue)

This is a fun game that teaches your dog to want to run away a short distance when there is a trigger approaching. While on walks, you simply say a word like “Here” or Follow”, and change directions moving the opposite way your dog is going. When they turn and see you start offering several food rewards and keep moving away. Some dogs love to chase, so for those dogs, initiate this game with quick first few steps. Start walking and sniffing again, and repeat. Pretty soon the word Here/Follow will predict a fun game of chasing you about 10 feet to get several treats. You can scatter feed when they get to you as well. This combines the find-it game for extra fun.

5. Utilize Sniffing More

Focusing on allowing your dog to sniff longer and process more environmental information will stimulate and satisfy your dog faster. By focusing on sniff instead of steps you stand less of a chance of walking by triggers that cause unwannted reactions. The more potential triggers your dog sees, the higher likelihood of a negative reaction while training. If you can get a good sniff in you can even cut the walk short and offer more frequent walks which your dog will likely prefer. Your dog will be just as tired as a longer walk most times. Consider play as a reward for 5 minutes after a sniffy walk. That way your dog gets the best of both worlds.

This is pretty simple. Start inside the home and condition the word find it by saying FIND IT! Then toss 5 -10 treats to the ground. Allow them to find and eat the food. Do this 5-10 times for practice. Then go outside and do the same. Choose a grassy area or any space of relative cleanliness.

6Don’t Walk Your Reactive Dog ( Just stop, sniff and reward anything else)

If you are noticing your dog reacts every time you walk, multiple times each walk or is getting worse with each walk, STOP GOING FOR WALKS! Change something because what you are doing isn’t working and if it is maintaining or getting worse, something on the walk is reinforcing the bad behavior. Consider just stepping outside and sniffing far away from dogs on a 10 foot line. You can usually manage a smaller area at a time vs. the entire walk where you may encounter many more triggers.

This is when you want to just reward any good behavior. Looking at you, seeing any person or dog, or squirrel with scatter feeding. Play touch and toss, throw a ball nearby but don’t go on a walk where you know the outcome is barking, lunging and a lack of cooperation. Your reactive dog can get more out of 5-10 min of sniffing, training and play than a walk where they practice getting better at barking and lunging. Remember to pick an area as far from other triggers as possible and avoid walking at peak dog hours in the AM and PM.

7. Walk one dog at a time

If you have more than one dog and either of them or both are reactive, do not walk them together. I advise you only walk your reactive dog when you can devote your full attention. You want to get the right exposure to the the environment each walk so you need to keep your head on a swivel for opportunities when they arise. This also goes for avoiding tiggers your dog can’t handle while training. Even picking up the second dog’s poop can be enough time for a dog to sneak up on you. If you utilize my advice on encouraging sniffing and allowing a little longer leash where appropriate, you can walk two dogs in a similar amount of time at 1 dog who wasn’t allowed to sniff as much and focused on following their owner with a limited leash lenth.

8. Use a Longer Leash

It sounds counter intuitive but trust me it can work. I suggest a 10 foot leash (Biothane preferably), that much of the time is looped in your hand with only 6 feet available until you dog needs more sniffing room. This is ideal as most dogs tend to pull to just get a little ahead to beat you to more scents. If they can meander forward and backwards, side to side more, they will end up walking much better and sniffing more even with a shorter walk.

A second benefit to a 10’ Biothane leash is there ability to sick to the ground (concrete, flat surfaces) with your standing weight on them. The longer leash is easy to step on in an emergency if you need extra control during a reaction.

9. Don’t Walk Your Dog When They are Excited

This is most common right when they get up or when you get home an absence like work.  A highly aroused and excited state of mind isn’t what you want with you when you are working on making good decisions and taking direction from you. The more excited and aroused your pet is the less information they can process at once. This increases what we call “tunnel vision” where your dog will be less able to listen and respond to you in the presence of triggers.

10. Carry a Sqeaker or Squeaky Ball in your Training Pouch. 

Yes, you can purchase individual squeakers by them selves or a squeaky ball to distract your dog in the even you don’t have other options. I suggest making a game of chase after squeaking the toy or a toss if its a ball so they don’t feel tricked. At some point this effect may wear off so us it wisely. Also, get a real training pouch. You will need to have plenty of easy access to food rewards. You don’t have enough space in your pockets and fanny packs aren’t very functional in my opinion.

Bonus Game

Look – at – That Game

This is a game that I use for over half of my reactive dog cases. It is simple as long as you follow a few rules. It teaches your dog to look at a trigger to get rewards from you. While you teach your dog it is good to look at scary or exciting things, they learn to look back at you to either get closer or farther away ( plus each dog or person begins to predict yummy food)

Step 1

Start the up down game first to condition looking at you for food. Do 10-12 reps. Mark each time your dog looks at you with a click or yes! followed by high value treats/food. Go to an environment with enough distance between you and your dog that when they see the trigger they don’t immediately blow up with reactivity. encourage sniffing, toss a few treats if needed to get that going. When your dog sees anything in the distance and ‘they look at that” , say Yes! or click and feed several treats. You may have to put them right on their mouth initially.

Step 2

Keep marking and feeding for each time your dog looks away at anything including potential triggers. This set up will help you get more successful repetitions of looking at triggers and getting rewards. After several successful attempts, delay the yes or click, wait for them to look back and say “hey you forgot to say yes!” then mark and keep feeding. This teaches the to look at that and then look back to you for food and or distance too. Only move closer if you are successful with this first. If your dog is still reacting, you are too close or the environment is too challenging. Change that!

Summary for Managing your Reactive dog

Reactivity is often a part of growing up for many dogs. Just like humans, they have problems with their emotions and reactions. While it is challenging and overwhelming for many dog owners, there are practical solutions to help your reactive dog. Understanding they are likely overwhelmed and fearful or just frustrated they don’t know another way to meet a new dog should help you understand what approach to use to help them.

Be patient, kind and teach them what to do vs what not to do. “Look” or “Find-it” around triggers.

Increase sniffing, slow down, Play more games outside, keep your sessions brief and more frequent.

Reduce corrective measures and equipment,  bring more food on walks and take deep breaths. 

Don’t forget to assess for any pain that could be contributing to the reactivity on walks. Hire a qualified dog trainer or behavior consultant with credentials ( IAABC, CCPDT, KPA) and keep a log of behaviors good and bad. This will help you remember your successes and where you really need improvements.