My wife and I rescued two new dogs last year in Dec 2023, a Rottweiler (Roman) and a Doberman (Gunner). We've had both breeds prior and she is a horse trainer so we've always had really well trained dogs. One of our two new dogs- Gunner the 120lb Doberman- was extremely pushy, lacked any structure, disregarded the rules, personal space, and discipline. He pulled hard on the leash and was reactive towards other dogs, bikers, and joggers outside our fence. He was reactive on the leash during walks and he bit both my wife and I multiple times early after his adoption, so we just didn't feel safe with him any more. We spent 6 months trying treats, positive only training (punishment would encite aggression), youtube videos, prong collars, e-collars etc, and finally decided to find a professional for help as we wanted to start having kids soon and we were exhausted tip-toeing around just waiting for the next bite incident. Through exhaustive research we found Dion and Ancillary K9 training. He was mentioned in multiple online forums as the "go-to" guy in Denver. He trains working dogs for scent work, bite work, protection work, as well as general obedience, reactivity, and aggression, so he understands large breeds and their behaviors. Many people had also mentioned that they had been to two, three, even four trainers first and they just weren't getting results and they finally ended up with Dion. We decided to skip all that time and money and effort and go straight to Dion as it was best for Gunner and our situation. We have had 4 sessions thus far and my wife and I have said multiple times that we wish we had done this as soon as we adopted. Dion doesn't just tell you what to do, he helps you reframe your perception of the relationship you have with your dog, and the reasons WHY things work and why things dont work. He trains YOU to become your dog's leader and then YOU train your dog. Anyone can teach a dog to sit or do simple tricks, but it takes someone like Dion who understands dog behavior and psychology to truly modify and reframe desirable and undesirable behaviors. I explained above that Gunner "was" all of these things and I used the past tense as he IS now a phenomenal dog. He's incredibly smart and with structure, rules, and effective tools and methods of communication, we have been able to build a fantastic relationship with him. He knows his place in our pack and we are able to lead him effectively. He is happier now and he has more freedom to join us wherever we go. He is no longer reactive on the leash or at our fence. He's at ease and calm even in chaotic environments, and he respects us and our heirarchy in the household. We get so many compliments on how well he's trained by the vet and people we see on walks all over town. Gunner was rescued from a kill shelter in Texas and we had run out of options. Dion helped us learn the tools we needed to be effective leaders and to create a happy home for Gunner and every dog to come after him. We can't thank you enough Dion! read more

If I could give Dion at K9 Ancillary more than 5 stars, I absolutely would. When we first came to him, our Staffordshire Terrier had a very difficult past. He had a serious Grade 3 bite history and significant trauma from a previous owner, and we suspect he may have even been used in dog fighting. We were overwhelmed, scared, and honestly unsure if we would be able to keep him. From day one, Dion never judged us or our dog. Instead, he took the time to teach us how to understand our dog's behavior, build trust, and most importantly, keep ourselves and everyone around us safe in every situation. He didn't just train our dog--he gave us the knowledge and confidence to become better owners. One thing that truly sets Dion apart is that he cares about the whole dog, not just obedience. During one of our training sessions, he noticed our dog's severe skin allergies and recommended switching him to a raw diet. Within just two weeks, the transformation was incredible. His skin cleared up, his allergies dramatically improved, and he became a much happier, healthier dog. That advice alone changed his quality of life. Because of Dion, we made the decision to keep our dog instead of giving up. Looking back now, we can't imagine our lives without him. That is something we will always be grateful for. Over the course of this journey, Dion has become much more than a trainer. He has been a mentor, a source of encouragement, and a genuine friend who has supported us every step of the way. It's rare to find someone who is this knowledgeable, compassionate, and truly invested in both the dogs and the people he works with. If you're looking for someone who will not only train your dog but also teach you how to build a lasting relationship with them, I cannot recommend Dion and K9 Ancillary highly enough. Thank you for helping us save our dog, giving us confidence, and changing all of our lives for the better. We are forever grateful. We are very happy an thankful to say he is very happy boy who lives an amazing life. read more

After much internet sleuthing for a dog trainer who would provide lasting results, I kept circling back to Dion's website. Multiple peers recommended board-and-train programs, but I ultimately preferred to be involved in my dog's training. This strengthened our relationship and has made maintaining what we both learned during our sessions straightforward. Although Dion specializes in reactive and "problematic" dogs, his training methods are equally applicable to dogs who struggle with the basics. My dog, Reicher, fell into the latter category. When we first started, he had absolutely no leash manners or recall. I dreaded walks with him, because he would incessantly drag me along. Pre-training, Reicher was also quite fond of darting out of the house and refusing to come back. This caused many stressful situations for both me and others. I avoided taking him with me out of fear that he would run away and be hit by a car before I could get him back. Fast forward about a year since we completed our sessions, and I have a completely different dog. Reicher gets compliments on his manners both on and off-leash. Using the e-collar has made it possible to supplement his reliable recall with off-leash adventures when appropriate. One of my fears about training was whether it would impact his friendly and goofy personality. Instead, it has allowed both of us to have clear communication regarding expectations, and he now has much more freedom. As a trainer, Dion is clear about the outcomes to expect from his program and empowers you and your dog with personalized advice to achieve success. He stands by his lifetime guarantee and responds promptly to any issues or questions that arise, both during and after training. read more

After several months of trying to find experienced trainers, I finally came across Dion. It was so hard to find someone who not only knows how to help me and my dog, but also did not look down at me for being so young. Dion has always been firm, with both my dog and me (trust me, we need it) but he has never been harsh or unkind. Since the first time I met him, Dion has always cared about not only my dog's wellbeing, but also mine. I can't tell you how many times he has offered me an extra pair of gloves or a jacket just because he thinks I am too cold. He is also very personable and you can tell he really listens, and remembers, when you tell him things. Before coming to Dion, Spike, a decently large German Shepherd, would drag me everywhere, pull me towards other dogs, and growl at people when they would walk by. After the first session of training, Spike no longer pulled me on our walks, but would nicely heel right beside me. Dion helped me teach him how to be patient and gain self control, by teaching him how to sit and watch (he can sit and wait both on and off leash now). Now, after 5 sessions, Spike will heel his whole walk, he can ignore other dogs, and he will nicely walk past people. Not only this, but with Dion's help, and a lot of practice, Spike can also play ball and heel off leash. Not only has he helped me with the bad habits I knew Spike had, but he has also pointed out habits that I didn't even know could be an issues. He doesn't just point them out, but he explains how to fix the behavior, and real world examples of how the behavior could be an issue. I would not have been able to do any of this without Dion's help. I would definitely recommend him if you and your dog need help. read more

Dion Studinski, owner of Ancillary K9 is a rare breed. He is not only quick to understand the behavioral, and emotional issues of the dogs; but is able to read the owners' limitations/patience as well. My dogs are quick and eager to learn. Dion commands respect through his proven training methods, repetition and patience. I learned by watching Dion w my dogs, that they are equally responsive and incented with praise as they are with prime rib. I am awed time and again by Dion, the Trainer; but also by Dion the Person. He has certainly shown compassion and understanding when one of my dogs was facing a possible court mandated euthanasia. My dog escaped from the yard when a worker carelessly left the gate ajar. My dog injured another dog while off leash. Dion took the time to meet with me and my dog and check the dogs response to commands while off leash around another dog just to reassess whether the dog he knew and had worked with had become a dangerous, aggressive dog. It was determined that he was the same sweet, loving, dog he had always been, who is simply strong and likes to play rough but will respond to his commands. Dion was instrumental in saving my guy from the guillotine. I have had other dogs and other trainers. After knowing and working with Dion, there is no other!!! He is kind, well spoken, and effective. Like choosing a surgeon, you want the best. That's Dion!! Julie Capps Fleming read more

Two years ago I rescued Gilbert, a truly remarkable but quirky and energetic dog. My best friend thinks he was struck by lightning as a puppy, only partly in jest. I think I did a great job raising him, but Dion has been a revelation. He's given me such an amazing set of tools to help Gilbert and me and our roommates all live together more happily. In part this was Dion correcting mistakes I didn't realize I was making, like using a harness despite Gilbert pulling all the time, but more than that Dion helped me understand how Gilbert thinks. I remember thinking, confused, how can it be that a stranger understands my dog better than me? It's a testament to Dion that he does. He also understands me as a dog owner, and has been empathetic and accommodating of who I am and what I want from owning a dog. I cannot recommend Dion enough. If all you want is to correct minor inconvenient behavior, he's your trainer. If you want to get your dog off leash on trails, he's your trainer. And, though I don't want to take Gilbert to dog shows or through agility exercises, I believe if you do Dion is also your trainer. For your sake and your dog's sake, spend an hour with him. You'll look back and wonder why you spent so long not properly training your dog. read more

I reached out to Dion as I am looking to train dogs myself and was curious about the industry. I called Dion on a Monday afternoon leaving a voicemail requesting to shadow him as he worked with clients. Dion called back within the hour (he was the only trainer to call back). He was enthusiastic and helpful. He recommended books and other resources. That same week on Friday Dion arranged for me to shadow him with two clients and their two pups. He throughly explained his philosophy and practice. I watch him work and was very impressed. He is a natural with the dogs and is skilled at communicating to his human clients how to work most effectively with their dogs. The dogs seems so advanced and quick to follow his commands I was shocked it was only their second session. After the hour I spent watching him work he took another hour of his time to explain what his was doing with the dogs and some basics about the industry. He also answered all my questions and provided further resources. I really appreciated Dion's time and enthusiasm. Dog trainers must apprentice to learn their trade and Dion's willingness to work with newcomers and share his experience with such passion and detail is a rare and special find. read more

I have an Akita puppy that completed 2 levels of group training classes at one of the big pet stores. She would listen for treats but was becoming aggressive towards my other dogs. Other trainers and breeders told me I'd have to get rid of her for my other dogs' safety. I was desperate for help when I contacted Ancillary K9. I signed up for the obedience package with the hope of being able to turn things around and keep my 6 month old puppy. After the first training session, I could see a huge difference in her attitude. She looked up to me as a leader and actually started listening without me having to bribe her with treats. We just completed our training yesterday and she is a totally different dog! The aggression is a thing of the past. She's 9 months old now, and she's my best behaved dog. Dion is amazing at what he does. He does a phenomenal job working together with the dog and owner. If you want to learn how to train your dog and gain their respect, Ancillary K9 is the answer! read more

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! read more

I cannot express enough how thankful I am for working with Dion! Absolutely worth the investment of time and money. As a first-time dog owner, I was super excited to adopt Huck but also incredibly nervous as I had no idea what I was doing. Huck is a 1-year-old German Shepherd/Husky mix and is quite loving, but also quite stubborn. The initial period of having Huck before I took him to Ancillary K9, I had moments of panic where I'd think, "what did I get myself into" - versus now I feel more comfortable and confident when handling my dog after just a handful of sessions. Dion's instructions are clear and easy to follow, and he really focuses on teaching YOU how to handle your dog. So many of my friends have also commented on how well-behaved Huck is now. With Dion's help, our lives have become SO much easier! read more

Outstanding training experience! We worked with Dion to train both our 7-year old Mastiff "Rocky" and our 6-month old puppy "Ford". Rocky had recently been attacked by two other dogs, which had drastically changed his overall demeanor towards both dogs and humans. After just the first session, we felt that we had regained control of him on leash (regardless of distractions), and over the next several sessions with Dion, we were able to progress him to being well responsive to off-leash! Dion also helped us set a solid foundation with our new puppy "Ford", and as a result we have a full confidence in and control of him both on and off-leash! Dion's approach follows a very logical progression, is easy to understand, and results in immediate results. Highly recommend Ancillary K9! read more

I was looking for a balanced trainer and Dion was recommended. He has a great manner and is very good with dogs. Within 5 minutes of starting lesson 1 my dog was already anxious to display obedience. Dion is calm yet assertive and clearly understands the psyche of a dog. My dog walks in a perfect heel on the leash, is able to be in a down stay for over an hour, and she is very relaxed when we have people over. Last week at our neighborhood garage sale she was "down" at the top of the driveway and endured literally dozens of strangers - several with dogs - and she barely paid any mind. We got so many comments on how well behaved she is. That happens on our walks, too. Pick Dion and Ancillary K9 and you will have a well-trained animal! read more

We recently adopted a 2 yr old rescue dog. In spite of training several dogs in the past, we were not making progress with his aggression towards other dogs and his single minded hunting instinct. We travel extensively with our dogs and were starting to worry we might need to rehome him. From the first training session, we saw amazing improvement in how we worked with the dog and how he responded to our direction. Dion gave us clear instructions on what we needed to do between sessions. He is very professional, supportive, and listened to our questions and concerns. We are back on the road as a family, our dog's behavior is now drawing attention for how well he behaves. read more

Dion was very easy to get a hold of initially and throughout our training period. He was very hands on with training and made sure that my husband and I worked with the dogs during the session. He catered training to our dogs who have completely different personalities. We had a rambunctious puppy mixed with an older, slow dog that had some recent fights with other dogs. He helped us work with both of them. We now have two dogs that sit, lay down, come to us, walk great on a leash, and have significantly improved in their reactions to other dogs...which is pretty amazing given their history. read more

So thankful for Dion and Ancillary K9. My dog Rami became aggressive and what seemed like untrainable after Covid. Being alienated from the outside world took a toll on all of us- especially him. We picked Ancillary K9 after reading the great reviews. I went from sheer terror walking Rami to trusting him on a long leash at a park with surrounding dogs. He continues to grow and is happier every day. Thank you Dion for training me and my good boy. We're forever grateful! read more

Ancillary K9 has made all the difference for our pup. Dion is an excellent teacher to both dogs and humans--he made sure that we understood how to handle our dog, and communicate expected behaviors. Our sweet dog is now a dream to take on walks and hikes, and she responds to our commands even in stressful/busy situations. We would definitely recommend Dion to anyone! read more

I have a wild child German Shepherd I could barely go a couple blocks before she dart at everything that passed by. After the first training with Dion, I was walking a new dog. Dion is skilled at identifying the reasons why my dog acted the way she did and how to correct her unruly behaviors. If you're looking for quick and amazing results, hire Dion! read more

Dion is an amazing trainer! People noticed how different our lil guy was after his training sessions! He is so much more enjoyable to take on walks, and we can control him well in different situations. Dion taught us how to communicate with our dog in a way that he understood and obeyed. Definitely recommend! read more

Dion is a no nonsense Teacher of dogs and Humans. In 3 sessions he is transformed our 2 year old "pound dog" Willy, that came to us with some serious issues, into a much more happy, trusting and responsive companion. We have a long way to go but we are sure that Dion is the trainer to get us there. read more