Chris Park K9 · Behavior Specialists

Aggressive & Reactive Dog Training in MA & NH

If your dog lunges, barks, growls, or has become unpredictable around dogs or people, you’re in the right place. Led by a retired police K-9 officer with 25+ years of experience turning difficult dogs into calm, reliable companions.

  • Retired Police K-9 Officer
  • 25+ Years of Experience
  • Expert Off-Leash Trainer
  • Thousands of Dogs Trained

Sound familiar?

What Counts as Aggression or Reactivity

Most owners aren’t sure what to call their dog’s behavior — and the label matters less than the plan. We work with all of it.

Leash reactivity

Lunging, barking, or spinning at dogs or people on walks.

Dog-to-dog aggression

At parks, fences, or between dogs inside your own home.

Resource guarding

Protecting food, toys, furniture — or a favorite family member.

Fear-based aggression

Growling or snapping when startled, cornered, or handled.

Overarousal

Excitement that tips into nipping, mouthing, or uncontrollable behavior.

The difference matters

Reactive or Aggressive?

The reactive dog

Overwhelmed — not dangerous

Barking and lunging are usually distance-seeking: “get away from me” or “I can’t handle this excitement.” Explosive, but the intent is space.

The aggressive dog

Intends to make contact

The behavior looks similar on a leash, but the goal is different — and so is the training plan.

The first job of our evaluation is telling them apart. Many dogs labeled “aggressive” are actually anxious, under-structured dogs who have learned that explosive behavior works.
The Chris Park K9 training team with four dogs at the Salem, NH facility
Chris and the training team at the Salem, NH facility
Why owners trust us with hard cases

Trained by a Retired Police K-9 Officer

Chris Parkiotis spent his career as a police K-9 handler working dogs in high-pressure, real-world environments — not sterile training rooms. That background shapes how we handle serious behavior cases.

  • Calm, confident handling — no fear, no frustration, no shortcuts
  • Balanced training built on structure and clarity
  • Real-world proofing around dogs, people, traffic, doorways
  • Owner coaching, so progress survives the trip home
How it works

From Evaluation to a Changed Dog

Free In-Person Evaluation

We meet your dog at our Salem, NH facility, see the behavior firsthand, and give you an honest read on what’s driving it.

Most aggression cases

Board & Train, 2–4 Weeks

Your dog lives with us. Daily structured training with controlled, safe exposure to triggers — the fastest way to reset rehearsed patterns. For milder reactivity, private lessons can be the right start instead.

Owner Handoff & Follow-Up

Hands-on lessons so the new behavior transfers to your household, plus follow-up support as routines return to normal.

Straight answers

Aggressive Dog Training FAQs

Can an aggressive dog really change?

In our experience over 25+ years, the overwhelming majority of aggressive and reactive dogs improve dramatically with structured training. The evaluation gives you an honest, case-specific answer before you commit to anything.

Is Board & Train safe for a reactive dog?

Yes. Reactive and aggressive dogs are our specialty, and exposure to other dogs is controlled, gradual, and supervised at every step. Dogs are never simply thrown together.

Do you work with dogs that have bitten someone?

We evaluate every dog individually, including dogs with a bite history. The free in-person evaluation lets us assess your dog safely and tell you honestly what training can accomplish.

How long does aggressive dog training take?

Most aggression and reactivity cases go through our 2–4 week Board & Train program, followed by owner lessons and follow-up support. Milder leash reactivity sometimes resolves through private lessons over several weeks.

What training methods do you use?

Balanced training — clear structure and boundaries paired with positive reinforcement, tailored to your dog at the evaluation. We show you exactly how everything works before we use it.

Start this week

The longer a dog rehearses aggression, the more automatic it becomes.

Get an honest assessment from a trainer who has spent 25 years handling hard dogs. Free, in person, no pressure. Explore our training programs or reach out today.