Reactive Dogs: Why Your Dog Overreacts & How to Help

If your dog barks, growls, or lunges at other dogs, people, or even passing cars, you’re not alone. Many pet parents live with reactive dogs—and while it can be stressful, reactivity is manageable with the right knowledge and support.

In this guide, we’ll break down what causes reactivity in dogs, how it differs from true aggression, and what steps you can take to help your dog feel more secure.

WHAT IS REACTIVITY IN DOGS?

Reactivity in dogs refers to an overreaction to specific stimuli—often other dogs, people, or sudden movements or sounds. A reactive dog might bark, growl, pull on the leash, or lunge, especially when they feel anxious or threatened.

This behavior can look like aggression, but reactivity in dogs is usually rooted in fear, frustration, or a lack of socialization—not a desire to harm.

WHAT CAUSES DOG REACTIVITY?

There are several factors that can lead to leash reactivity or general reactivity in dogs:

• Fear or anxiety (especially in fear-aggressive dogs)

• Past trauma or negative experiences

• Frustration from being on a leash

• Lack of early socialization

• Breed tendencies or high arousal levels

Understanding the “why” behind your dog’s behavior is the first step toward building a training plan that works.

REACTIVITY VS. AGGRESSION

Reactivity and aggression are often confused. The key difference is intent.

• Reactive dogs are typically overwhelmed and responding out of fear or overstimulation. They’re saying “I’m uncomfortable” or “I need space.”

• Aggressive dogs intend to cause harm and often show more persistent, escalated behavior.

If you’re unsure where your dog falls on the spectrum, a consultation with a dog behaviorist for aggression or a reactive dog trainer can help guide your approach.

HOW TO TRAIN A REACTIVE DOG

Training a reactive dog requires time, consistency, and empathy. Here are a few expert tips:

1. Work With a Professional

Look for dog training for reactive dogs, ideally with a certified trainer or behaviorist who specializes in reactivity or fear aggression dog training.

2. Use Positive Reinforcement

Punishment can increase anxiety and make reactivity worse. Instead, focus on rewarding calm behavior and creating positive associations with triggers using desensitization and counterconditioning.

3. Avoid Triggers When Possible

While working on training your dog, avoid situations that trigger reactivity. That might mean walking at quieter times or keeping more distance from other dogs.

4. Train for Better Leash Skills

Many reactive dogs are specifically leash reactive. Use tools like a harness, or special leash for reactive dogs to maintain control and reduce frustration. 

5. Give Them Space to Relax

Reactivity is emotionally draining. Make sure your dog has a safe space at home to decompress, and use calming aids or enrichment to support their overall well-being. For noise reactive dogs, a white noise machine can help to dampen outside noises.

ASK THE VET: DOG REACTIVITY FAQs

What is leash reactivity?

Leash reactivity happens when a dog becomes agitated or overexcited while on leash, often barking, lunging, or growling at other dogs, people, or objects. It’s usually caused by frustration or fear.

How is dog reactivity different from aggression?

Reactivity is typically rooted in emotion, like fear or excitement. Aggression includes intent to harm. A dog can be reactive without being aggressive.

Can reactivity be cured?

Reactivity can often be significantly improved with the right training, patience, and management. While some dogs may always be sensitive, many can learn calmer responses over time.

What’s the best leash for reactive dogs?

Use a sturdy short (4-6 foot) leash paired with a front-clip harness or head halter for better control. Avoid retractable leashes, which can make reactivity worse.

How can I stop my dog’s aggression toward other dogs or humans?

Work with a professional who understands how to stop dog aggression towards other dogs or how to stop dog aggression towards humans. It’s critical to create a training plan tailored to your dog’s triggers and learning style.

Can fear-based aggression be treated?

Yes. Fear reactive dog training focuses on building trust, changing emotional responses, and reducing exposure to triggers. Progress can take time, but it’s possible with consistency and support.

Is my puppy just reactive, or something more serious?

Some reactive puppies grow out of it with socialization and training, while others need structured support early on. If your puppy shows signs of fear or aggression, talk to your vet or a trainer.

Have more questions about reactivity in dogs? Book an appointment with your vet to get personalized advice for your pet.