Ancillary K9, Denver's premier dog behavior expert, transforms challenging behaviors with personalized, intensive training. Our certified trainers address aggression, anxiety, and obedience issues. Clients see rapid, lasting results, often within six sessions. Our programs empower you and your dog for long-term success. With our Lifetime Training Assurance, we guarantee free retraining if your dog regresses. Offering private training and 24/7 support, we help rebuild harmonious relationships.
Training & services
Training goals
Behavior consultationProgram details
Expert training to address unwanted behaviors such as anxiety, reactivity, or aggression. We create customized plans to correct issues, build positive habits, and improve your dog's overall behavior, ensuring a happier and more balanced companion.
Comprehensive training designed to address complex behavioral issues such as anxiety, reactivity, and aggression. Tailored to your dog's unique needs, this program focuses on lasting solutions for a well-balanced and well-behaved companion.
Effective behavioral modification for dogs with anxiety, fear, reactivity, or other challenges. We address root causes and help dogs become confident and calm, providing solutions for behavioral problems with customized training in Denver.
Leash training
Obedience trainingProgram details
Professional dog obedience training to teach essential commands, improve manners, and build a solid foundation for behavior. Ideal for dogs of all ages, ensuring they are well-behaved at home and in public. Serving Denver and nearby areas.
Puppy trainingProgram details
Trusted puppy training in Denver to build confidence and teach basic commands. We guide your puppy through early learning stages for better behavior, social skills, and obedience. Perfect for new dog owners in the Denver area.
Socialization
Behavior support
Aggression trainingProgram details
Specialized training to address aggression toward people or other dogs. We identify root causes and use proven techniques to build trust, improve behavior, and ensure safety. Tailored for lasting results and a stronger bond with your dog.
Specialized aggressive dog behavior training to reduce reactivity and manage aggression. Our expert trainers help your dog overcome triggers and develop safer responses. Ideal for dogs showing aggression toward people or other dogs.
Fear and confidence
Reactivity trainingProgram details
Fast, effective reactive dog training in Denver for dogs that bark, lunge, growl, or struggle around other dogs and people. Practical training that gives you and your dog confidence and peace of mind.
Resource guarding
Separation anxiety
How training happens
Board and train
Group classes
Owner coachingCustomer-reported
Private trainingProgram details
One-on-one private dog training tailored to meet your dog's unique needs. Focus on obedience, behavioral issues, or aggression with customized sessions designed for faster results. Serving Denver with personalized, professional dog training solutions.
Dog age
Puppies
Support between sessions
Homework and practiceCustomer-reported
Personalized training plans
Assistance and working dogs
Protection trainingProgram details
Protection dog training in Denver focused on control, obedience, confidence, and reliable behavior. Training is tailored to the individual dog, owner, and their goals.
Dog size
Large dogsCustomer-reported
Your dog’s background
Rescue dogsProgram details
Dog training in Denver for rescue dogs adjusting to a new home or dealing with fear, anxiety, reactivity, or behavioral issues. We help build the bond between you and your dog.
Consultations
Free consultation
Other listed services
View 29 additional details
Dog trainingProgram details
Professional dog training to improve obedience, resolve behavioral issues, and reduce aggression. Tailored training programs for dogs of all ages and breeds, designed to achieve quick, lasting results. Serving Denver and nearby areas.
Aggressive Behaviors
Basic Commands
Behavioral Evaluations
Behavioral Program
Canine Rehabilitation
Court-ordered dog trainingProgram details
Court-ordered dog behavior training for legal compliance. Our training includes professional, detailed reports to meet court requirements. Available for Denver pet owners needing a thorough rebuilding of their dog's behavior.
Dog Behavior Assessments
Dog Bites
Dog Evaluations
Dog Park
Dog Starts
Dog Trainers Schedule
Dog behavioristProgram details
Dog behaviorist specializing in solving behavioral issues like anxiety, fear, aggression, and reactivity. We provide tailored, humane behavior solutions to help dogs thrive in any environment. Serving Denver and surrounding areas.
Dog's Barks
Dogs Treats
Family Dogs
Guard Dogs
Obstacle Courses
Off-leash dog trainingProgram details
Expert off-leash dog training to ensure your dog listens reliably, even without a leash. We focus on building recall, focus, and responsiveness, providing the freedom to explore while staying under control. Serving Denver and nearby areas.
Shelter Dog
Dog Temperament Assessment
Dog Temperament Test
Working Dog Training
Dog Anxiety TrainingProgram details
Trusted dog training for anxious. We work on building confidence, creating structure, and transforming your dog's behavior.
Seperation Anxiety Dog TrainingProgram details
Separation anxiety dog training in Denver for dogs that struggle when left alone. We’ll build a practical training plan to help your dog become confident and independent.
Destructive Dog TrainingProgram details
Dog training for destructive behaviors like chewing and damaging the home. We’ll help your dog building better habits, boundaries, and structure.
Dog Expert WitnessProgram details
Expert witness services for dog-related legal matters. Professional insight into canine behavior, temperament, aggression risk, and other issues in legal cases.
Dog Behavior Consulting for Legal MattersProgram details
Professional dog behavior consulting for legal matters. Experienced insight into canine behavior, aggression risk, evaluations, and other factors relevant to legal cases.
Confirm current programs and availability directly.
Questions & answers
From Google
What people have asked about this business.
Do you offer protection dog training?
Hi there! Yes, we offer Colorado's most trusted Protection Dog Training. We'll provide an assessment to ensure your dog is right for the role. Then we'll embark on a training journey that transforms your companion into a protection dog, and you into a strong handler. Please get in touch if you have more questions!
Community answer · Ancillary K9 Dog Training · 2025-12-21
Are there certain breeds that your dog training works best with?
Hi there! Though we have extensive knowledge and experience with Schutzhund and working breeds, our training is designed to work for any breed of dog. All breeds of dogs can have behavioral and aggression issues, and our training is equipped to tackle them all. If you have more questions, please get in touch!
Community answer · Ancillary K9 Dog Training · 2025-09-21
I'm struggling with a dog with serious behavior issues. Training in the past hasnt worked. Do you have any guarantees for your training?
Hi there! We specialize in hard to train or "problem dogs." Training is possible, even if other programs haven’t worked in the past. We are experts in dog behavior & obedience, and we guarantee fast, drastic changes in your dog. All of our programs come with Our Lifetime Support Guarantee, which is our promise to stand by you and your dog until your goals are achieved, as well as offering re-training if necessary.
Community answer · Ancillary K9 Dog Training · 2025-09-21
Do you offer puppy training? I have a puppy that's already starting to show some aggression and is proving hard to train.
Yes, we offer trusted puppy training. We correct your puppy's behavior fast, ensuring they have the best start at life. Correcting their behavior when they're young is the best way to see them grow to be a well-adjusted and happy adult dog. We'd love to help you tackle their behavior issues. Get in touch to get started!
Community answer · Ancillary K9 Dog Training · 2025-09-21
Private dog training offers tailored attention for specific behaviors and learning styles. It allows for flexible scheduling and results in faster progress. Our sessions are ideal for addressing unique issues, reducing distractions, ensuring a safe environment, and meeting individual goals. Owners receive immediate feedback and benefit from a private, relaxed setting, making it a preferred choice over group or board and train programs.
Community answer · Ancillary K9 Dog Training · 2023-09-21
In our training approach, we draw from the same methodologies used by law enforcement, military dog handlers, top sport dog trainers, and world-class competitors. Our methods are dynamic and are tailored to fit each unique situation. The tools and strategies we use hinge on the specific behaviors you want to address, your dog's individual temperament, and your proficiency and comfort as a handler. Our goal is effective, holistic training.
Community answer · Ancillary K9 Dog Training · 2023-09-21
Do you handle training for court-ordered behavioral assessments?
Yes, we are well-equipped to handle court-ordered dog training and behavioral assessments. We understand the seriousness and sensitivity of these cases. Our team is able to provide comprehensive evaluations and design tailored training programs to address specific behavioral concerns. We're here to assist and ensure that both you and your dog navigate this process effectively. Please reach out to us to discuss your needs and learn more about how we can help.
Community answer · Ancillary K9 Dog Training · 2023-09-21
Yes, we have extensive experienced in addressing canine aggression. Whether it's biting, growling, or other aggressive behaviors, we employ evidence-based techniques to manage and reduce these behaviors. We understand that aggression can stem from various underlying causes, and our approach is both compassionate and tailored to each dog's individual needs. Our goal is to ensure safety and foster healthy dog-owner relationships.
Community answer · Ancillary K9 Dog Training · 2023-09-21
Yes, we absolutely offer puppy training! Starting early is key to a well-behaved adult dog. We recommend starting training for puppies once they reach 16 weeks of age and have been fully vaccinated against parvovirus. This ensures their safety while they embark on their training journey. Our puppy programs are tailored to the unique needs of young dogs, laying a strong foundation for future training. For a comprehensive overview, please visit our website.
Community answer · Ancillary K9 Dog Training · 2023-09-21
While our primary base is in the heart of Denver, our reputation has traveled well beyond city limits. In fact, we've had the privilege of working with passionate dog owners from as far as Vail and Aspen. This expansive reach underscores our commitment to excellence and the trust clients place in our services. Regardless of distance, we remain dedicated to providing premier dog training to help build stronger bonds between owners and their dogs.
Community answer · Ancillary K9 Dog Training · 2023-09-21
At the heart of our service, client success is paramount. We employ a diverse range of techniques and tools, ensuring each client benefits from the most effective and tailored training. Recognizing that questions and challenges arise, we provide unlimited phone, text, and email support between lessons, ensuring continuity in your dog's progress. Moreover, our commitment to you is unwavering, backed by our Lifetime Support Guarantee.
Community answer · Ancillary K9 Dog Training · 2023-09-21
We do not! We believe in providing holistic support throughout your training journey. Not only do we NOT charge for assistance between lessons, but we also prioritize open communication. To encourage this, we give all our clients direct access to their trainer's personal contact details. This ensures 24/7 availability for phone, text, and email support. We're committed to standing by you every step of the way.
Community answer · Ancillary K9 Dog Training · 2023-09-21
What is your policy if I am not happy with the training?
We operate on a mutual commitment principle. If you're fully engaged—attending sessions, asking questions, and completing homework—we'll match your dedication. Your input reflects the support you receive. While we're eager to help, progress requires joint effort. If you're fully committed, we'll stand by you and your dog until you achieve the goals you're aiming for.
Community answer · Ancillary K9 Dog Training · 2023-09-21
5/5Dion is awesome and I’d highly recommend his services.
We were originally unsure if we wanted to do professional dog training due to cost, but after reading reviews on Dion we decided to give it a try and it’s worth every penny. Within the first lesson Dion got our dog to stop p…Read full reviewClose full review
Dion is awesome and I’d highly recommend his services.
We were originally unsure if we wanted to do professional dog training due to cost, but after reading reviews on Dion we decided to give it a try and it’s worth every penny. Within the first lesson Dion got our dog to stop pulling on the leash and has taught us a handful of commands and skills to make our day to day life with our dog much easier. Training has also improved our relationship with our dog since we know how to handle any unwanted behavior. We used to get nervous to take the dog to public areas before know we can do so with confidence. It helps when we get compliments on his behavior, too!
Dion and his office are very personable and flexible.
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Will Duong
5/5We recently finished our training with Dion at Ancillary K9, and the growth has been incredible. We adopted our Pitbull, from a shelter. She had an altercation with another dog and was showing reactivity with other dogs that we didn’t know how to manage. That’s when I started to …Read full reviewClose full review
We recently finished our training with Dion at Ancillary K9, and the growth has been incredible. We adopted our Pitbull, from a shelter. She had an altercation with another dog and was showing reactivity with other dogs that we didn’t know how to manage. That’s when I started to research different trainers/facility, either leave your dog at a facility for a couple weeks and have a “perfect” dog or learn how to manage this problem and be able to keep control of your dog. I guess that was a no brainer that’s when I found Ancillary K9 and reached out to Dion.
Dion’s approach is thoughtful, structured, and realistic. He uses great metaphors that help you understand his methods and have a better understanding between you and your dog.
One thing I kept in my mind when starting this is never compare your dog to his, cause they’ve mastered the craft while we are still on training wheels. But it did set the bar of where I would like to see my own dog at.
Throughout the training, with the correct equipment and tools we were able to give her the proper guidance and structure. Currently she is great on the heel and being able to run with her by my side is amazing. Which is a night and day difference between being dragged around.
The tools and knowledge we gained from Dion will stick with me for life. Highly recommend Ancillary K9 for anyone who’s serious about building a better relationship with their dog.
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Melbee Hallam
5/5I can’t say enough about Dion and Ancillary K9 training. My husband and I decided to rescue a 12 week old puppy from a local rescue in the New Year. In the brief moments of meet and greet at the shelter the little guy was friendly, curious, super playful and seemed like the per…Read full reviewClose full review
I can’t say enough about Dion and Ancillary K9 training. My husband and I decided to rescue a 12 week old puppy from a local rescue in the New Year. In the brief moments of meet and greet at the shelter the little guy was friendly, curious, super playful and seemed like the perfect fit for our family. It wasn’t long before we discovered he was also really smart, and really stubborn. He was nipping constantly, at us humans and our cats, wouldn’t let my husband near him, we couldn’t get a leash and collar on him and he would eat ANYTHING he saw out in the yard. We were concerned we had made a big mistake and thought we might have to return him to the shelter, which felt terrible to me. We decided to consult with a trainer before making any final decisions, and that is when we found Dion and Ancillary K9.
After discussing the issues we were having with our little guy, Dion quickly got to the root of the problem and we got to work straight away. Within minutes he had a collar and leash on and within the next hour began walking calmly to heel. It’s been a few months now, and 5 sessions with Dion and we are so happy we decided to work with him. Dion has given us the tools we needed to succeed as pet parents. We get so many compliments on how well behaved he is for his age, and we are so proud of the progress he has made. Thank you Dion!
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Corazon Ocanas
5/5Dion has been incredible through this whole experience! I really appreciate that he dives into the "why behind the what" as I like to say. This really helps me understand as a dog owner what I need to do to help my dog succeed and the expectations I need to hold her to. When I fi…Read full reviewClose full review
Dion has been incredible through this whole experience! I really appreciate that he dives into the "why behind the what" as I like to say. This really helps me understand as a dog owner what I need to do to help my dog succeed and the expectations I need to hold her to. When I first got her, she was aggressive, pulling at the leash, and barking at everything. I never realized how much stress and caution I was holding when we went on walks and I would dread them. However, after a few sessions with Dion, our walks have become one of the best parts of my day. I also really appreciate how together Dion is and how he presents his business. You get a welcome folder that lists the gear
you need, along with resources and tips. He actively keeps track of what you and your dog have learned so far and I LOVE the flexibility of scheduling he provides! It's so convenient and easy. Thank you so much Dion for the skills you have provided us with and we will be recommending you always!
UPDATE JUNE 2025: I’ve been meaning to do this for a bit now because the other day I was going to walk my dog and started thinking about how great all the items Dion originally recommended are still working great! The collar, leash, and ecollar he recommended initially I still use daily and they have no sign of wear or tear. Thank you again Dion for not only providing us with a strong foundation but also supporting quality gear that’s so worth the investment. Still recommending you always!
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Gregg Engelkes
5/5When I first started training my dog, I felt like we had reached a limit. As my wife and I prepared for the arrival of our baby, I knew I needed my dog to be more well-behaved, especially around a newborn. I began researching various trainers, and even looked into places that off…Read full reviewClose full review
When I first started training my dog, I felt like we had reached a limit. As my wife and I prepared for the arrival of our baby, I knew I needed my dog to be more well-behaved, especially around a newborn. I began researching various trainers, and even looked into places that offered boarding programs where my dog could be trained for 4 to 6 weeks and returned fully trained. I spent hours reading reviews, looking at different options, and carefully considering the costs. There are dog trainers everywhere, but finding the right one for us seemed daunting. That’s when I came across Dion at Ancillary K9.
I carefully reviewed every page of their website, looking into the programs, philosophies, and fees. I’ll admit, the price was a hard pill to swallow—it was nearly the same value of my dog. But after a lot of thought and reflection, I made the decision to move forward. I scheduled a consultation with Dion, and from the very start, I was impressed by his keen observation and thoughtful approach. He took the time to assess my dog’s behavior and understand the specific challenges we were facing.
When we had our first session, I was cautiously optimistic but also a little skeptical. I thought to myself, “Is this really all we’re learning today?” However, even after just one session, I could already see changes in my dog’s behavior and his understanding of basic commands. It was enough to convince me that we were on the right track. So, I committed fully to the process—purchased the recommended equipment, read the book Dion suggested, and began diligently practicing the techniques he taught us.
As the weeks went by, and the sessions accumulated, the transformation in my dog was undeniable. What started as small shifts in his behavior evolved into significant, lasting changes. Dion’s methods—building on each previous lesson—helped us shape the well-behaved, responsive dog I had always hoped for. I began to notice how much more confident my dog was, how eager he was to follow commands, and how calm and in-control he became in various situations.
I decided to put my dog’s progress to the test during an annual camping trip, which always attracts around 50 people and several other dogs. It was the perfect opportunity to see how well he could handle distractions. As we interacted with friends, family, and other pets, I received countless compliments about how well-behaved my dog was—how calm and controlled he seemed amidst all the chaos. People were genuinely blown away, and I couldn’t help but feel proud to say, “Yes, he’s my dog!”
The trip also gave me a chance to test out some of the more challenging aspects of training, particularly when it came to handling distractions. Dion’s training had prepared us both for these moments. My dog was responsive, calm, and focused—even with all the new sights, sounds, and smells around him.
Thanks to Dion and Ancillary K9, my dog is no longer just well-behaved—he’s a joy to have in any environment. The investment I made was truly worth it. Dion’s personalized approach and dedication to his craft have made all the difference. I now have a dog that I’m not only proud of, but one I can trust to behave in any situation, whether we’re at home, out in public, or on an adventure.
I can confidently say that the training was an investment in the future of our family, and I’m incredibly grateful for the progress we’ve made. If you’re looking for a dog trainer who truly understands both the practical and emotional side of training, Dion at Ancillary K9 is the right choice. I couldn’t be happier with the results.
Original customer experiences from the collected Google data. Ratings without comments follow written reviews.