Why Is My Dog Aggressive To Other Dogs On Leash Walks?

Dogs can behave aggressively toward other dogs on walks for many reasons: fear, anxiety, stress, and frustration, to name a few.

It’s important to figure out why your dog is behaving aggressively and understand how she is feeling, so you can work towards addressing the problem.

Reasons for aggressive behavior in dogs

#1. Fear

Dogs may bark or behave aggressively to other animals or people if they are afraid of them. This is often because the dog is scared, anxious, or stressed.

When animals are scared, they respond with what are commonly known as the 4 F’s – Fight, Freeze, Flight, or Fidget.

Fight

If a dog is trapped on a leash and can’t get away from the scary thing, she may feel she has no other option but to “fight.”

This involves offensive aggression and is often the last resort as it carries with it a risk of injury, or worse (Westlund, 2021).

Dog bites can be really nasty and dog-on-dog aggression or, even worse, an actual dog fight are both incredibly scary. Things should never be allowed to escalate to this point.

Freeze

Sometimes a dog may just stand stock still, maybe turning slightly away or averting the eyes.

“Freezing is a type of evasion, animals will often go undetected if they’re still,” explains Dr. Westlund. 

I’m going to throw in an example here because this is a situation we encountered with our fearful rescue Saluki cross, Louis.

We thought we were doing him a big favor by taking him to the Dubai dog show.

Not to show him or have him participate in anything, but just to go and walk around the huge grassy show area and see other people and dogs.

We should have known better of course!

While he tolerated it the first year (and let me be clear, your dog should never have to tolerate something just because you think he should), the second year, as soon as we got out of the car and he realized what was happening, he refused to move.

He just didn’t want to go!

Poor Louis, we had unwittingly subjected him to something we thought he would enjoy but in fact, he had found being in the presence of other dogs to be incredibly stressful.

And so we let him jump back in the car and wait for us, where we went and did a quick walk around with our remaining three dogs.

Flight

A scared dog may run away if they have that option and are not restricted by a leash, a fence, or some other kind of restraint.

Fidget

Fidgeting is often a delaying or appeasement behavior. It may include the “offering and gathering of information in order to stop the situation from escalating,” says Dr. Westlund.

Examples in dogs include yawning when not tired, licking the lips without the presence of food, scratching when not itchy, sudden biting at the paws or other body part, sudden sniffing at the ground or other object, or an all-over body shake when not wet or dirty.

#2. Anxiety

A dog may be generally anxious about being out in the big wide world due to an overall lack of experience when she was younger, negative early learning experiences, poor socialization, bad experiences in general, or genetic disposition (some dogs are naturally predisposed to be more fearful, notably if the parents were also fearful or the mother had a high level of stress hormones during pregnancy).

#3. Frustration

Sometimes a dog may behave aggressively because they are frustrated and can’t get to the object of their desire.

This may be because they are constrained by a leash when they want to get to another dog, or are behind the garden fence when another dog goes past (known as barrier frustration).

I’ve got an example of this too.

Our dogs Daisy and Maggie did not get along – despite our best efforts (or so we thought at the time) at introducing them.

Many times, if Daisy saw Maggie outside in the yard and Daisy was in the house looking out, she’d nip at the closest person or dog near to her in frustration at not being able to get closer to Maggie.

And if no one was close, she nipped at the air.

Is my dog really aggressive?

This is very important. An adult dog behaving aggressively in a specific context or in the presence of a specific animal, person, or object does not necessarily mean you have an aggressive dog.

Describing a dog as “an aggressive dog” is often a misnomer.

It’s really more of a label, and it does the dog no favors whatsoever in trying to understand the root cause of the behavior or how she feels when engaging in the behavior.

In many cases, a dog displays aggression because she is anxious or frustrated about something in the environment. This may be another dog, an unfamiliar person, a loud noise – or just about anything else. Aggression is a behavior and not a personality trait.

Reactivity vs. aggression

“Reactivity is commonly confused with aggression,” explains Dr. Erin Rakosky.

“Reactive dogs overreact to certain stimuli or situations. Genetics, lack of socialization, insufficient training to learn self-control, a frightening experience, or a combination of these can cause reactivity, and fear is typically the driving force.”

If a dog barks or acts aggressively in any way when she sees other animals or people, it is most likely because the dog is afraid, stressed, or excited.

While it’s understandable that a dog owner thinks their dog is being aggressive, her behavior simply reflects her emotional state.

Reactive dogs are not necessarily aggressive, they’re just responding to the stimulus in their environment.

Unfortunately, reactive dogs often do get labeled as “aggressive” by well-meaning but misinformed dog owners.

This can lead to a lot of unnecessary stress and anxiety for both the dog and her owner.

The reactive dog

While a dog will be perfectly comfortable with and ignore many of the things in their immediate environment, there may be other things that cause them to react.

This could be because they feel:

a) Anxious and want the scary thing to go away.

In such cases, they may bark, lunge, growl, or pull on the leash, desperately trying to escape from the tall guy with a beard and baseball cap or the noisy group of kids on skateboards, or whatever other perceived threat they want to avoid.

b) Excited about the fun thing and want to get closer to it.

In such cases, they may also bark, lunge, growl, or pull on the leash, desperately trying to get closer to the other dog or group of teenagers grilling hotdogs on the beach, or whatever other exciting thing it is that they want to get closer to.

These scenarios are all very specific contexts where the dog behaves in a certain way because of how she’s feeling.

It doesn’t mean that the dog is aggressive all the time or that she has an “aggressive personality.”

Dogs do what they do to get what they want or need, whatever that may be at the time.

Defining aggression

Aggressive behavior “is a natural response to frustration or being cornered,” explains Dr. Karolina Westlund.

“Often, it doesn’t occur out of the blue. There’ll be signs of increased arousal.”

This is “potentially dangerous, may damage relationships, and the animal may learn to use aggressive behavior to get away from situations she doesn’t like.”

Learning to recognize the subtle signs that your dog feels uneasy and what her warning signs are (consider the Ladder of Aggression below) can go a long way to ensuring your dog remains under threshold emotionally and does not feel the need to react, much less escalate her behavior to full-blown aggression.

What are the signs of an aggressive dog?

In terms of dog behavior, a dog’s body language is always a good indicator of how the dog is feeling in any given moment.

There are many signs that a dog is emotionally aroused (again, this does not mean a dog is “an aggressive dog”), but here are some common ones:

• Growling or snarling
• Snapping or biting
• Lungeing or charging
• Raised hackles on the back of the neck
• Stiff body posture
• Staring
• Excessive barking
• Ears forward or flattened against the head
• Whale eye (whites of eyes showing)
• Body leaning forward
• Tail high, slowly wagging, or tail tucked under
• Growling

Canine Ladder of Aggression

In her Canine Ladder of Aggression, Dr. Kendal Shepherd (2004) shows the many ways in which dogs can react to stress or threats, as well as how their emotional state can escalate if initial warnings (ranked here from mild to severe) are ignored:

• Yawning, blinking, nose licking
• Turning head away
• Turning body away, sitting, pawing
• Walking away
• Creeping, ears back
• Standing crouched, tail tucked under
• Lying down, leg up
• Stiffening up, stare
• Growling
• Snapping
• Biting

A dog may not display every signal, and signals displayed by an individual dog at different times and in different contexts may vary.

Depending on the situation, dogs may progress up the ladder and engage in the various signs of aggression very quickly.

Says Shepherd: “It is most important to realize that these gestures are simply a context and response-dependent sequence which will culminate in threatened or overt aggression, only if all else fails.“

READ NEXT

Resources

• Behavioural medicine as an integral part of veterinary practice – Dr. Kendal Shepherd in BSAVA Manual of Canine and Feline Behaviour (2nd edition)
• ‘Look at That’ LAT Game -teaching dogs to focus and eye contact – Positive Dog Training 
• Puppy Behavior and Training – Socialization and Fear Prevention – Debra Horwitz, DVM, DACVB & Gary Landsberg, DVM, DACVB, DECAWBM
• RAGE – Animal Emotions/Module 8 [Educational Course] – Dr. Karolina Westlund/Illis Animal Behaviour Courses
• The Canine Ladder of Aggression – Dr. Kendal Shepherd
• The First Eight Weeks: Socializing Puppy Litters in a Shelter or Foster Home – Center for Shelter Dogs
• What Is Aggression? Dog Reactivity vs. Dog Aggression – Erin Rakosky, DVM