Is your dog struggling with barking, lunging, or otherwise mouthy behaviors? These behaviors may look aggressive from the outside, and it’s tough to know when you should be concerned and who you should turn to for help.

The line between reactivity and aggression can be blurry, and the solution for your dog will depend on their unique personality, experiences, and triggers.

The difference between reactivity and aggression in dogs

Reactivity and aggression are both situational behaviors that depend largely on the dog, and telling the difference between the two isn’t always straightforward. Let’s dive into the differences between reactivity and aggression.

What does reactivity look like in dogs?

Your dog experiences reactivity whenever they respond to a situation (or a trigger) in a more intense way than you would expect, like overreacting to a sound or the presence of another person or animal.

Your dog may have these big feelings when they:

• See other dogs
• Hear fireworks, thunder, or other loud noises
• See large moving vehicles
• Are around certain people like men or children
• Are on a leash

Reactivity doesn’t look the same for every dog. The situations that a dog will react to differ, and so do the ways in which they react to those situations.

For some dogs, their reactivity can look like aggressive behaviors, like growling or lunging. In other cases, the reactive behavior can look like fearfulness, barking, or even being overly friendly toward strangers or other animals.  

What does aggression look like in dogs?

Many reactive behaviors are mistaken for aggression. Aggression is the threat of harm to another individual, and these behaviors can include:

• Snarling
• Growling
• Snapping
• Biting
• Barking
• Lunging

Animals will generally try to prevent conflict, not create it. If an animal has resorted to aggressive behaviors like biting or lunging, it's likely because their more subtle, lower-level stress signals have been missed or ignored. 

These are usually missed because most people haven't been taught what to look for when it comes to dog body language. 

There are different types of aggression seen in dogs, and many of them are situation-dependent.

Resource guarding, for example, is a common dog behavior because it’s a natural instinct. From the dog’s perspective, it’s perfectly reasonable to protect their property from being taken away.

Other dogs may show aggression when they’re frustrated, such as when they’re forced into a kennel.

Because there is such a range of aggressive behaviors seen in dogs, it’s important to partner with a trained professional to better understand your dog, their behavior, and their triggers.  

What is your dog's threshold? 

When exposed to a trigger, every dog has a specific threshold they can handle before their behavior becomes erratic. For reactive dogs, this threshold is lower than for non-reactive dogs. 

Their threshold depends on the intensity of the trigger and the intensity of the environment.

For example, someone who has a fear of spiders may remain in a calm state when seeing a small spider 10 feet away in a glass cage, but would likely be above threshold if a large spider were crawling on their arm. 

Some dogs have multiple triggers. For example, a dog may be reactive towards both dogs and new people.

In this case, if multiple triggers are present in a situation, the triggers stack on top of one another, and your dog may reach their threshold quicker than if only one of the triggers is present. 

In addition to triggers, your dog's environment, health, recent stressful events, and other factors can also affect their ability to cope and move them toward their threshold. 

When dogs are above threshold, they're no longer in a thinking/learning state of mind, which is why people find that nothing works to calm their canine in those situations. 

Before your dog reaches their threshold, distance is your best friend. Creating separation between your dog and their trigger helps move them into a calmer state. 

If your dog stays in this heightened state for too long, continues to be exposed to this situation, or receives punishment for their reactive behavior, their behavior can escalate even farther.

Your dog may also learn to skip displaying lower level signs altogether because they've learned these cues don't work. 

This is where you risk your dog tipping into aggressive behaviors. 

When should you seek professional help for your dog's behavior?  

The sooner you can reach out to a behavior professional, the better. If you’re questioning your dog’s behavior, it’s best to reach out to a behavior consultant who studies and understands canine communication.

A professional behavior consultant will take into account:

• What does the dog look like? (body language)
• What is the dog responding to?
• What are the situations in which this behavior presents itself?
• How often is the behavior presenting?
• How can you create ways to manage the environment to prevent the continued practice/display of the "undesired" behaviors then create a plan to help your companion learn a more preferred response when seeing said trigger

It's also important to discuss your dog's behavior with your vet. Sometimes aggression or sudden changes in behavior can be the result of an underlying medical issue, and no amount of behavior modification or management can resolve a medical issue. 

If your dog has already been diagnosed with anxiety and they’re displaying aggressive behavior, a veterinary behaviorist will be the best fit for you. They are dually trained in animal medicine and animal behavior to holistically address your dog’s situation.