Meet Thirza
I am an equine movement scientist, educator and professional horse trainer from the Netherlands, working at the intersection of science, practical experience and equine function.
A lifelong curiosity about horses—and experiences that challenged what I thought I knew about movement and training—led me to explore the horse from the inside out and adopt a functional perspective. That journey has taken me from training arenas to universities, dissection rooms and research settings, and continues to shape how I teach, assess and work with horses today.
Science keeps my training honest. Practical experience keeps my science relevant. Curiosity creates the bridge between them.
My lifelong curiosity about horses
My relationship with horses began long before I ever imagined working with them professionally. As an 11 year old, I spent every possible moment at the local stable, mucking out, filling hay nets, cleaning tack and, most importantly, watching horses. I became fascinated by how they behaved, how they interacted with one another and how they responded to the people around them.
That curiosity continued as I grew older. I worked as a groom for an international carriage driver, rode and competed in dressage, explored jumping and began teaching at seventeen. These experiences taught me that working with horses is about far more than learning techniques. Observation, timing and understanding the individual horse are just as important.
I later studied political science with the intention of pursuing a diplomatic career. Horses, however, remained the constant thread running through my life. Eventually, I found my way back to them and began looking for a deeper understanding of how horses function.
The horse who changed everything
While studying, I wanted a horse of my own but had very little money. I found Acaliena, a young mare from a retiring breeder who nobody seemed to want. She was about to be sold for slaughter, and I bought her for €1,400.
From the beginning, things were difficult. She bucked, reared and resisted in ways that were often interpreted as behavioural problems. I followed much of the advice available to me at the time, but something never quite felt right.
I sought help from veterinarians, an osteopath and a saddle fitter, and continued trying to understand what was happening. Then one accident changed everything. Acaliena almost killed me.
She survived, and I spent time beside her while she recovered. In the process, she became my greatest teacher.
I began to realise that I had been asking how to make my horse do something, rather than asking why she was struggling to do it in the first place. Her behaviour, movement and physical responses were telling me something, but I did not yet have the knowledge to understand what I was seeing.
From questions to science
During an internship in Hong Kong, I realised that a career in diplomacy was no longer where I wanted to go. I took a year away from university to focus on understanding Acaliena and the questions her behaviour had raised.
I explored different approaches to training and movement, and began working with people who were looking at horses from very different perspectives. Meeting Zefanja Vermeulen and later helping to translate course material for Sharon May Davis led me to my first whole horse dissection.
During the dissection, I saw anatomical findings that closely matched problems I had observed in Acaliena. A specialist later confirmed the pathology. For the first time, I could see a connection between what I had experienced as a trainer and what was happening within the horse's body.
I realised I had been trying to train a body I did not yet understand. That became the beginning of a much deeper scientific journey. I returned to university to study how horses function, move and adapt, exploring the relationship between anatomy, movement, environment and training.
My work today
Since then, my work has taken me into universities, anatomy laboratories, rehabilitation environments, medical research and training arenas. I have worked with domestic and feral horses, explored different breeds and environments, and continued to learn through observation, research and whole horse dissection.
I am now an equine movement scientist, exercise physiologist, educator and professional horse trainer. As part of the Equine Studies Dissection Team, I participate in approximately fifteen whole-body dissections each year, working alongside veterinarians, biologists and other professionals to examine the relationship between structure and function.
Today, my work brings together three perspectives that do not always meet: scientific exploration, education and practical Functional Horse Training.
Science keeps my training honest. Practical experience keeps my science relevant. Curiosity creates the bridge between them.
My aim is not to provide another training system or simply give people more information. I want to help people develop the knowledge and skills to observe their horses, understand what they are seeing and make informed decisions about management and training.
Function comes before fashion. I believe we should look beyond whether a horse can perform a task and consider how they are doing it, what it costs them and whether that task is appropriate for the individual horse.
Beyond horses
Outside my work, I am still simply a curious and creative person. I love photography, designing educational material and finding ways to make complex science easier to understand.
I am also a huge Freddie Mercury fan, could happily listen to David Attenborough narrate almost anything, and greatly admire the work of Professor Alan Wilson.
At the heart of it all, I am still simply a horse girl who is endlessly curious about how horses work and passionate about helping people understand them a little better.
