Dog Aggression: When Your Dog Is Aggressive to Other Dogs

Dog aggression toward other dogs is one of the most serious behaviour problems. It's also widely misunderstood.

📖What We're Talking About

• ●Fighting or attempting to fight with other dogs
• ●Biting that causes injury
• ●Escalated conflict beyond normal dog squabbles

📖What We're NOT Talking About

• ●Normal squabbles that resolve quickly
• ●Growling or snapping that serves as communication
• ●Reactivity without actual aggression (see our leash reactivity guide)

📖Why It Happens

💙Fear/Anxiety

• ●Dog attacks out of perceived need to defend themselves
• ●"Get away from me" aggression
• ●Often has history of being attacked or under-socialised

🛡️Resource Guarding

• ●Protecting food, toys, resting places, or owner
• ●Other dog approaches → aggression

⚠️Social Aggression

• ●Competition over hierarchy
• ●Often same-sex (especially intact males)
• ●Can occur between housemates

📖Predatory

• ●Large dog toward small dog
• ●Triggered by movement
• ●Different brain system than other aggression

📖Frustration

• ●Dog wants to greet/interact but can't
• ●Frustration tips into aggression
• ●Common with barrier frustration

📖Pain/Medical

• ●Underlying pain makes dog defensive
• ●Sudden aggression can signal health issue
• ●Always rule out medical first

📖Learned

• ●Aggression works (other dog leaves, owner intervenes)
• ●Behaviour is reinforced
• ●Escalates over time

Before addressing aggression, you need to understand its patterns.

📖Questions to Answer

📖Context

• ●Where does aggression occur? (Home, walks, dog parks)
• ●Who is it directed at? (All dogs? Certain types? Familiar dogs?)
• ●What happens just before? (Approach? Resource present? Restraint?)

📖Triggers

• ●Specific types of dogs (same sex? Specific breeds? Size?)
• ●Specific situations (food nearby? On leash? In doorways?)
• ●Specific behaviours from other dogs (staring? Approaching? Playing?)

📖Warning Signs

• ●What does your dog do before attacking?
• ●Stiffening, staring, raised hackles?
• ●Or does it seem to come from nowhere?

📖History

• ●How long has this been happening?
• ●Getting worse or stable?
• ●Any specific incidents that started it?

📖What Happens After

• ●How does your dog recover?
• ●Quickly or prolonged arousal?
• ●Any injuries caused?

🐕Write This Down

Keep a log. Patterns emerge that help with management and treatment.

📖Professional Assessment

For serious aggression, a qualified behaviourist should assess in person. They can identify things you might miss and create a safe plan.

Before any training, you must prevent injuries. Management is essential.

📖On Walks

• ●Muzzle training (for everyone's safety, including your dog's)
• ●Strong lead and secure harness
• ●Avoid off-leash areas
• ●Cross the street to avoid other dogs
• ●Walk at quiet times/places

🏠At Home (Multi-Dog Household)

• ●Separate when unsupervised
• ●Barriers between dogs during high-risk times
• ●No shared resources (food, chews, toys)
• ●Management structures (baby gates, crates)

🐕With Visitors' Dogs

• ●Don't force interactions
• ●Separate rooms
• ●Managed introductions only (if at all)

🎯Muzzle Training

A properly fitted basket muzzle allows panting, drinking, and treat-taking. Muzzle training should be positive - the muzzle predicts good things. This is safety, not punishment.

📖Never

• ●Let them "work it out" (they won't safely)
• ●Use punishment (increases anxiety and aggression)
• ●Put other dogs at risk during training
• ●Ignore warning signs

📖The Purpose

Management prevents practice. Every fight reinforces the behaviour. Every prevented fight is a win.

Dog-to-dog aggression often requires professional intervention.

📖You Need a Professional If

• ●Any bite that breaks skin
• ●Multiple fights
• ●Aggression is escalating
• ●Aggression seems unpredictable
• ●You feel unsafe managing the situation
• ●Someone's been injured (person or dog)
• ●You're unsure of the cause

📖What Kind of Professional

🧠Veterinary Behaviourist

• ●Vet with behaviour specialisation
• ●Can prescribe medication
• ●Best for complex or severe cases

🧠Certified Applied Animal Behaviourist

• ●Advanced training in behaviour
• ●Can create treatment plans
• ●May work with your vet for medication

🧠Qualified Behaviourist

• ●APDT, CCAB, or equivalent credentials
• ●Force-free approach
• ●Experience specifically with aggression

🚫Avoid

• ●Anyone who talks about dominance
• ●Punishment-based approaches
• ●Flooding (forcing exposure)
• ●Guarantees of "fixing" the dog

📖What a Professional Does

• ●Thorough assessment
• ●Identifies triggers and patterns
• ●Creates management plan
• ●Designs behaviour modification protocol
• ●Ongoing support and adjustment

📖Medication

For many aggression cases, medication helps by reducing baseline anxiety. This makes behaviour modification more effective. Not every case needs medication, but many benefit.

If working with a professional, this is what the process typically involves.

🐕Desensitisation and Counterconditioning

Similar to reactivity training but with higher stakes.

📖The Concept

• ●Expose to other dogs at a distance that doesn't trigger aggression
• ●Pair with positive experiences (treats)
• ●Very gradually decrease distance over time
• ●Dog learns: other dogs predict good things

📖Critical Differences from Reactivity

• ●Higher risk (actual bite potential)
• ●Slower progression
• ●More management between sessions
• ●Often requires muzzle as safety backup

📖What This Looks Like

1. Other dog visible at distance (50+ meters initially) 2. Mark and treat your dog for calm behaviour 3. Other dog leaves, treats stop 4. Repeat many times 5. Very gradually decrease distance 6. If any aggression, increase distance

📖Time Frame

• ●Months, not weeks
• ●Lifetime management may be needed
• ●Some dogs improve significantly
• ●Some need permanent restrictions

📖Between Sessions

• ●Full management (no uncontrolled dog encounters)
• ●One bad incident sets you back significantly
• ●Prevention is part of treatment

🎯Realistic Goals

Aggression may be manageable but not curable. The goal is often "can safely avoid/redirect" not "loves all dogs."

Some dogs will always need management around other dogs. That's okay.

📖Adjusting Your Lifestyle

• ●Walks at quiet times/places
• ●No off-leash in public
• ●Dog parks are not for your dog (ever)
• ●Planned, controlled interactions only

📖Quality of Life

• ●Your dog can still have a great life
• ●Long walks, hiking, swimming, training, play with you
• ●Not every dog needs dog friends
• ●Many are happiest as the only dog

🐕If You Have Multiple Dogs

When aggression is between your own dogs: - Long-term separation strategies - May need to rehome if safety can't be maintained - Rotation schedules - Professional essential

💊Mental Health (Yours)

• ●Living with an aggressive dog is stressful
• ●It's okay to feel frustrated, sad, or overwhelmed
• ●You're not a bad owner
• ●Seek support from others in similar situations

📖When Rehoming Is Considered

Sometimes, despite best efforts, a home isn't right. If: - Safety cannot be maintained - Someone has been seriously injured - Quality of life (dog's or yours) is severely impacted - The dog would be safer in a different situation (single-dog home, experienced handler)

Rehoming with full disclosure to an appropriate home isn't failure. It can be the responsible choice.

If you're reading this with a puppy or non-aggressive dog, here's how to prevent problems.

🤝Puppy Socialisation

• ●Positive exposure to many dogs during socialisation window (8-16 weeks)
• ●Quality over quantity (one good interaction beats five scary ones)
• ●Puppy classes with appropriate play
• ●Advocate for your puppy (remove from overwhelming situations)

📖Choose Interactions Wisely

• ●Not every dog needs to greet every other dog
• ●On-leash greetings are often problematic
• ●Teach your dog that other dogs are no big deal (ignore them)

📖Watch for Warning Signs

• ●Stiffness around other dogs
• ●Hard stares
• ●Resource guarding emerging
• ●Overly rough play
• ●Bullying behaviour

📖Intervene Early

• ●If you see concerning behaviour, address it immediately
• ●Consult behaviourist before it escalates
• ●Prevention is easier than cure

📖Neuter/Spay Considerations

• ●Reduces some types of same-sex aggression
• ●Not a magic fix
• ●Timing matters (discuss with vet)
• ●Won't help learned aggression

🚫Avoid

• ●Dog parks with no supervision
• ●Letting dogs "work it out"
• ●Ignoring early warning signs
• ●Forced greetings

📖The Best Prevention

A well-socialised dog who sees other dogs as neutral or positive, taught to check in with you rather than react to other dogs, and never put in situations where aggression is practiced.

If you're past this point, don't despair. Many aggressive dogs can improve with proper management and behaviour modification. But prevention is always easier.