---
title: Aggressive Dog Training in Boulder, CO | Koru K9
description: Specialized aggressive dog training in Boulder, CO. Koru K9 offers expert behavior rehabilitation for human aggression, dog aggression, resource guarding.
---
★★★★★ 4.9 from 1,200+ client reviews
Balanced dog training since 2013 · Serving 7 states across the US
Call us: [415-583-5412](tel:4155835412)
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[Home](https://www.koruk9.com/?hsLang=en)› [Locations](https://www.koruk9.com/dog-trainer-locations?hsLang=en)› [Colorado](https://www.koruk9.com/dog-trainer-locations/colorado?hsLang=en)› [Boulder](https://www.koruk9.com/dog-trainer-locations/colorado/boulder/dog-board-train?hsLang=en)› Aggressive Dog Training
Boulder · Aggressive Dog Training
# Boulder *Aggressive Dog Training*
Our services include private, in-home dog training, and our popular board and train programs. We also offer dog training services in Denver.
[Book a Free Consultation →](https://www.koruk9.com/contact-us/?hsLang=en) [Call 415-583-5412](tel:4155835412)
**3–8 week** programs **Max 5 dogs** per trainer **2×** weekly photo & video updates
★★★★★
“Whether we’re your first call or your last hope.”
**Programs from $3,600 · GPS collars · Max 5 dogs**
How does aggressive dog training work in Boulder?
Our team has extensive experience with aggressive dogs as well as problem behaviors that many families have difficulty dealing with. We recognize every dog and owner has individual needs, so we craft a plan that is tailored to help them fulfill their goals. Not only do our methods benefit your pet, but they also teach owners to comprehend their dog’s behavior.
Problem behaviors we help with
## Behavior we work with in Boulder
If the reactivity, anxiety, fear, or aggression feels unfixable, we want you to know it’s not.
[Tell Us About Your Dog →](https://www.koruk9.com/contact-us/?hsLang=en)
### Aggression
Dog-to-dog aggression, Human aggression, Resource or food guarding, Dogs fighting
### Fear & Anxiety
Fear based behaviors, Separation anxiety, Generalized anxiety, Destructive behaviors
### Obedience Issues
Pulling on leash, Not coming when called, Jumping, Excessive barking
Our philosophy
## Let the *heeling* begin.
Ever wonder why some Boulder dog Board & Train programs promise quick fixes or take a one-size-fits-all approach, only to leave you with unreliable results and behaviors that come back? That doesn’t mean your dog is broken — it means they need a different approach.
At Koru K9 Dog Training in Boulder, our Board & Train programs are built for real-life success — not shortcuts. We focus on lasting behavior change through connection, consistency, and clear communication.
**Real-life training in real environments.** Each day includes structured sessions, field trips, and exposure to everyday distractions — city sidewalks, parks, and real streets, never a kennel run.
1–5
Client dogs per trainer — never more
2×
Photo & video updates weekly
GPS
Collars & secure home environments
0
Kennels — home-based, always
How it works
## How aggressive dog training works in Boulder
We treat every dog as if they were our own — because we know how much they mean to you.
1
### Pick-up day
Pick up and drop off are part of every program. Your dog travels safe and settles into their trainer’s home.
2
### Life in a real home
Your dog lives with a professional trainer — structured sessions plus playtime, exercise, and rest, never a crowded facility.
3
### Real-world training daily
City streets, parks, and field trips — with at least two photo/video updates per week so you follow the progress.
4
### Delivery & go-home lesson
We personally deliver your dog back and teach you everything they’ve learned — plus two follow-up lessons.
Your local team
## Koru K9 trainers serving Boulder
Local trainers who live and work where you do.
Certified Behaviorist, Koru Master Program Graduate
### Cyndi Wright
Denver, CO
Certified BehavioristKoru Master Program Graduate
Cyndi has worked as a dog walker and sitter for over 20 years but she discovered her passion for dog training while rehabilitating a rescue Siberian Husky.
[Read full bio →](https://www.koruk9.com/dog-trainer-locations/colorado/boulder/aggressive-dog-training#bio-cyndi-wright)
Dog Behaviorist
### Thomas Vytlacil
Denver, CO
Dog Behaviorist
I’ve been a dog advocate for more than 25 years working with organizations such as Stray Rescue out of St. Louis and adopting a variety of pups abandoned and left to wonder if they were worth loving.
[Read full bio →](https://www.koruk9.com/dog-trainer-locations/colorado/boulder/aggressive-dog-training#bio-thomas-vytlacil)
Dog Behaviorist
### Jenna Zulauf
Denver, CO
Dog Behaviorist
Jenna Zulauf is a passionate and dedicated professional dog trainer with over a decade of experience working with dogs. She furthered her education by attending Tarheel Canine School for Dog Trainers, where she graduated as a…
[Read full bio →](https://www.koruk9.com/dog-trainer-locations/colorado/boulder/aggressive-dog-training#bio-jenna-zulauf)
×
### Cyndi Wright
Denver, CO
Certified BehavioristKoru Master Program Graduate
Cyndi has worked as a dog walker and sitter for over 20 years but she discovered her passion for dog training while rehabilitating a rescue Siberian Husky. Although she had grown up with dogs her whole life, this was her first experience with a reactive and aggressive dog. As her dog became increasingly difficult around unfamiliar dogs and people, Cyndi began to feel their world shrinking.
Determined to find more than a quick fix, she turned to Koru K9’s balanced training approach—and the transformation was life-changing for both of them. The results spoke for themselves. Friends, family, and neighbors began asking what she had done to improve her dog’s behavior, and she quickly realized how many dogs—and their people—could benefit from the same tools and structure.
What started as helping others informally became a calling. Cyndi pursued formal education in balanced dog training to confidently support dogs with even the most challenging behaviors. Today, Cyndi works as a Dog Behaviorist and Balanced Trainer, helping improve the lives of dogs while empowering their humans.
She recognizes that every dog and every family is unique, and she tailors her training plans to meet individual needs. She focuses on in-home training, working directly with clients both in their homes and in real-world environments where behaviors typically surface. When she’s not working with clients, you’ll find Cyndi hiking with her dogs or curled up on the couch with them and a good book.
[Book a Free Consultation →](https://www.koruk9.com/contact-us?hsLang=en)
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×
### Thomas Vytlacil
Denver, CO
Dog Behaviorist
I’ve been a dog advocate for more than 25 years working with organizations such as Stray Rescue out of St. Louis and adopting a variety of pups abandoned and left to wonder if they were worth loving. I’ve been an entrepreneur since I was 26 owning restaurants, a clothing line, and consulting for corporations.
I bring my life experience to training dogs and horses on my small farm in Black Forest Colorado. I sought to work with Koru K9 because of their philosophy around helping the core issues that keep the dog and the owner from a fulfilling relationship together.
If I’m your last resort or you want to take the steps to teach your dog valuable life skills, I will be dedicated to giving you my very best and helping you discover your dog’s true potential!
[Book a Free Consultation →](https://www.koruk9.com/contact-us?hsLang=en)
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### Jenna Zulauf
Denver, CO
Dog Behaviorist
Jenna Zulauf is a passionate and dedicated professional dog trainer with over a decade of experience working with dogs. She furthered her education by attending Tarheel Canine School for Dog Trainers, where she graduated as a certified professional pet trainer, strengthening her knowledge and expertise in professional dog training and behavior.
Jenna believes in going the extra mile—not only with her clients, but with her own dogs as well. She actively competes in PSA (Protection Sports Association), continually challenging herself and her dogs to reach higher levels of performance, teamwork, and reliability. One of her proudest accomplishments was competing at PSA Worlds 2025, with her dog, Jax.
An experience that reflects her commitment to putting in the time, dedication, and hard work required to excel in the sport. What truly sets Jenna apart is her passion for helping people build better relationships with their dogs. She understands that every dog and owner is different, and she takes pride in creating practical, individualized training that helps owners better understand, communicate with, and enjoy their dogs.
Whether working through everyday obedience, behavioral challenges, or pursuing higher-level goals, Jenna is committed to helping both dogs and their people succeed. With years of hands-on experience, professional education, competitive accomplishments, and a genuine love for what she does, Jenna brings dedication, knowledge, and enthusiasm to every dog she works with.
[Book a Free Consultation →](https://www.koruk9.com/contact-us?hsLang=en)
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More reviews
## Results from families like yours
Verified reviews from clients across every market we serve.
★★★★★
“I am SO happy we invested in Koru K9. We got matched with Natalie and Lee as our trainers and they have been INCREDIBLE.”
TL **Tasha LaRue**Verified client review
★★★★★
“Rob was professional, flexible, and had many resources he was happy to share! Thank you for your time!”
V **Vickie**Verified client review
★★★★★
“I took my 1 1/2 year old 'hyper' aussie doodle, Gigi for a 3 week board and train with Irini.”
AM **Annemarie M.**Verified client review
[Write Us a Review Today](https://www.google.com/maps?cid=16938504931794498991)
Questions
## Boulder aggressive dog training FAQs
Does Koru K9 offer aggressive dog training in Boulder, CO?+
Yes, Koru K9 specializes in aggressive dog training and behavior rehabilitation in Boulder, Colorado. They work with complex behavioral issues including human aggression, dog-to-dog aggression, resource guarding, and territorial behavior that other trainers turn away.
What training options are available for aggressive dogs in Boulder?+
Koru K9 offers two primary options for aggressive dogs in Boulder: private in-home training (which coaches owners directly in their home environment) and intensive 4-to-6-week board-and-train programs in a trainer's home for 24/7 rehabilitation.
How many dogs does each trainer work with?+
Each trainer works with just 1–5 client dogs at a time, ensuring your dog receives focused attention, personalized dog training, and plenty of affection in a real home environment. This small, intimate setting allows our expert trainers to tailor each session to your dog's unique personality and behavior challenges—whether it's leash reactivity, separation anxiety, or basic obedience. Your dog isn't just trained—they're cared for like family.
How much attention will my dog get?+
Your dog will receive exceptional care, personalized training, and plenty of individual attention throughout their stay. In our Board & Train program, each trainer works with only 1 to 5 dogs at a time. This intentionally small size ensures your dog receives the focused support they need to succeed. Each day includes multiple one-on-one training sessions, play, physical exercise, and rest. Your dog will live in the trainer's home—not a kennel—and will be treated like one of their own. We don't just teach commands, we help your dog build confidence, trust, and the skills they need to thrive at home and in the real world.
How do you keep my dog safe and secure?+
Your dog's safety is our top priority at Koru K9. During our Board & Train program, your dog lives in a safe, structured, and supervised home environment—not a kennel facility. This allows for 24/7 monitoring, individualized care, and secure containment when dogs are not actively training or supervised. Each dog is housed in a crate when unattended, which not only ensures safety but also supports structure and calm behavior. Our trainers follow strict safety protocols to prevent injury, stress, or accidents. From controlled environments to professional handling, our training programs are designed to keep your dog safe, secure, and thriving throughout their stay.
Will my dog remember me after their board & train?+
Yes — your dog will absolutely remember you after completing their Board & Train program. Dogs are deeply bonded to their people, and that connection doesn't disappear during training. In fact, time spent apart often strengthens the bond. Rest assured you will be greeted with tails wagging, full-body wiggles, and all. Throughout the program, your dog is learning new skills, gaining confidence, and practicing calm behavior. When you reunite, you'll see not only a dog that remembers you, but one that is the best version of themselves. Our go-home lesson helps you step into your new role as the leader your dog needs, and we provide clear, personalized guidance to make the transition smooth and successful. With continued consistency at home, you'll build an even stronger relationship with your dog.
## Other dog training programs in Boulder
### In-Home Dog Training
In-Home Dog Training for Boulder dogs and their families.
[Explore In-Home Dog Training →](https://www.koruk9.com/dog-trainer-locations/colorado/boulder/in-home-dog-training?hsLang=en)
### Dog Behaviorist
Dog Behaviorist for Boulder dogs and their families.
[Explore Dog Behaviorist →](https://www.koruk9.com/dog-trainer-locations/colorado/boulder/dog-behaviorist?hsLang=en)
## Your companion is worth it. Your peace of mind depends on it.
Whether we’re your first call or your last hope, Koru K9 will meet you — and your dog — where you are, and help you build the calm, confident companion you’ve been searching for.
[Book a Free Consultation →](https://www.koruk9.com/contact-us/?hsLang=en) [415-583-5412](tel:4155835412)
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**Koru K9 Dog Training & Rehabilitation**
455 Market St Ste 1940, PMB 999798
San Francisco, CA 94105-2448
[415-583-5412](tel:4155835412) · [woof@koruk9.com](mailto:woof@koruk9.com)
Office Hours: Monday–Friday 8am–5pm PST
#### Services
[Board & Train](https://www.koruk9.com/dog-training-services/board-train?hsLang=en) [In-Home Training](https://www.koruk9.com/dog-training-services/private-in-home-training?hsLang=en) [Hybrid Training](https://www.koruk9.com/dog-training-services/hybrid-training?hsLang=en) [Puppy Training](https://www.koruk9.com/dog-training-services/puppy-training?hsLang=en) [LunaDog AI — Online](https://www.koruk9.com/lunadogai-dog-training-app?hsLang=en)
#### Locations
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#### Resources
[Behavior Guides](https://www.koruk9.com/guides?hsLang=en) [Blog](https://www.koruk9.com/blog?hsLang=en) [FAQs](https://www.koruk9.com/about-us/faqs?hsLang=en) [Become a Trainer](https://www.koruk9.com/become-a-trainer?hsLang=en) [Careers](https://www.koruk9.com/careers?hsLang=en) [Contact](https://www.koruk9.com/contact-us?hsLang=en)
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