Photo of a female rider (Sandra Bonow, SLU) with a chestnut horse jumping over a hurdle in an indoor riding arena.
Sandra Bonow, doctoral student in the project “Optimized breeding for healthy and high-performing sport horses through linearly described traits,” pictured here with the SWB horse Bon Helix. Photo: Lisa Chröisty, SLU

Distinguishing characteristics of healthy versus high-performance horses? A new tool for future horse breeding

Page reviewed:  04/10/2025

The Swedish Warmblood is Sweden's most common riding and competition horse. When it comes to breeding, the delicate balance between high performance and soundness is important as well as difficult. So, which physical characteristics of the horse are actually linked to durability versus performance?

Being born into a body with good capabilities

Horse welfare is a hot topic, and the debate frequently touches on issues such as horse sustainability. There are many factors that influence whether a horse stays healthy or becomes injured. However, one important factor is that the horse's body and basic physical condition are good from the outset and developed for sustainability.

But it's not obvious what traits make a horse durable and injury-free.

Is it better to have a long or short body?

    • Scale: Long body type—Short body type

  • Is it better for the horse to move smoothly or to have a tighter gait?

    • Scale: Soft movements—Tight movements

  • Is it better if the horse is of a coarse build, or if it is more of a noble type?

    • Scale: Coarse—Noble

Doctoral student Sandra Bonow is currently investigating how factors such as these affect horses of the Swedish Warmblood (SWB) breed. Research that has the potential to yield very exciting and significant results.

Targeted breeding: Performance and/or durability?

Over the past fifteen years, the SWB horse breeding has become increasingly focused, and in some cases extreme, on producing the “super horse” that performs well in various sports. The horses we see today at the very top of equestrian sports have become increasingly agile: show jumpers are more sensitive and responsive, and dressage horses have larger and more “flashy” gaits.

However, the characteristics of the horse that have led to successful performances have not previously been mapped. This is where doctoral student Sandra Bonow began her project—by identifying the characteristics that seem to indicate that a young horse will be successful in one of the major equestrian sports in the future.

We could see that there was a big difference between the characteristics associated with success in show jumping horses and dressage horses. For show jumpers, good characteristics linked to jumping ability were particularly important, but so were conformation and, in fact, an elastic canter. And for dressage horses, conformation and a good trot were particularly important, while, for example, walk was not nearly as important for how well they would perform later in life, says doctoral student Sandra Bonow.

The focus has subsequently shifted from performance to health, and which characteristics are important for a horse to have a long, injury-free, and sustainable life. Even though horses can live to be 20-30 years old, many horses today are injured early in life in ways that can affect both their lifespan and quality of life.

Similar to how different dog breeds today have developed extreme appearances that may not always be beneficial to their well-being, one might wonder whether there are risks to sustainability in that the breeding of our sport horses has gone to extremes in terms of performance in show jumping and dressage, says doctoral student Sandra Bonow, continuing: Which is what makes these studies so incredibly exciting.
Collage with two images: On the left, a rider (Sandra Bonow, SLU) on horseback outdoors on an autumn day; on the right, two foals in a paddock in autumn.
For each new generation of horses, there is an opportunity to preserve traits that may be linked to both sustainability and performance. Future results from this project could prove to be a valuable tool in this regard. Photo: Lisa Chröisty, SLU

Survival analysis – how long horses survive before sustaining their first injury

To answer this important question, the research team now has access to both injury statistics and descriptions of characteristics from several thousand horses.

This means that we can look at horses and see if there are clear correlations between certain physical characteristics of the horses and how often they have been injured later in life, says Sandra Bonow.

The descriptions of the horses' characteristics come from young horse tests, where over the last fifteen years it has become increasingly common for horses not only to be assessed but also described, the latter based on around 50 characteristics. These can include everything from the length of the horse's back, its leg position, movement patterns, the size and airiness of its gaits, its ability to jump high, and so on. This is what is known in the horse world as linear descriptions, where the horse is given a score not based on how good it is in relation to a goal, but rather on a scale between two extremes in all these different characteristics.

And it is by comparing these descriptions with injury statistics that we can obtain results, says Sandra Bonow, continuing:
Right now, I am conducting a survival analysis, which, simply put, involves looking at how long horses can survive before suffering their first injury. For me, this involves a lot of analysis and computer work, and it is very exciting work.

High performance or sustainability – is it possible to have both?

You want horses that perform extremely well and are healthy, sound, and sustainable in the long term, says Sandra Bonow.

But the question is: Is it possible to have both?

Perhaps, is the answer at this point. There is still a year left of the project and not all the data has been analyzed yet. But once that has been done, and it is possible to see a connection between different characteristics in horses and how well they perform and stay injury-free, it is possible that a new tool will have been added to Swedish horse breeding.

The hope is also that this project will have a ripple effect and open up opportunities for more people to conduct further research into this aspect of horse health and welfare.

It is important that we provide horses with the conditions they need for a long and healthy life, and breeding is the first step in this process. If we can ensure that more horses are born with good physical conditions, we will have laid a solid foundation, concludes Sandra Bonow.
Close-up of the face of a chestnut horse standing in a stable.
Photo: Lisa Chröisty, SLU

Facts about the project:

About the project:

  • Funded by the Horse Research Foundation and expected to run from 2024 to 2026.
  • The doctoral student in the project is Sandra Bonow, together with a research group consisting of:
    • Åsa Gelinder Viklund, Principal supervisor for the project, researcher and associate professor in animal science, specializing in breeding and genetics at the Swedish University of Agricultural Sciences (SLU).
    • Susanne Eriksson, Researcher and associate professor in applied animal genetics at SLU.
    • Erling Strandberg, Professor of Animal Genetics at SLU.
    • Elin Hernlund, veterinarian, researcher, and associate professor of movement mechanics at SLU.

The project can be easily divided into the following parts:

1. Distinguishing between stallions that produce “show jumpers” and “dressage horses”
During the 1980s, most stallions in SWB breeding were so-called “all-round horses,” producing offspring that were suitable for several different sports. In recent years, it has become increasingly clear that breeding (and thus also the horses) has become focused on either show jumping or dressage. The first part of the project mapped which SWB stallions should be classified as “show jumping stallions” and “dressage stallions.”

2. What characteristics are important for high-performing show jumpers/dressage horses?
What characteristics are linked to successful performance in show jumpers? And what characteristics are linked to successful performance in dressage horses?

3. Correlation between different groups within the horse breed (gender, focus, competition history) and their health/injuries:
Using insurance data for more than 15,600 SWB horses, differences in injury history among different categories within the breed will be investigated, such as:

  1. Show jumpers versus dressage horses
  2. Competitive versus non-competitive horses
  3. Gender (mares, stallions, geldings)

The study will primarily examine injuries related to the horse's musculoskeletal system, i.e., lameness of various types and origins.

4. Correlation between characteristics linked to health/injuries:

Based on the above insurance data and the characteristics of each horse described in young horse tests, investigate which characteristics of the horse (on a scale between two extremes, e.g., long back—short back) can be linked to durability or injuries.

In this step, a genetic aspect will also be incorporated to see if there may be hereditary explanations for some of the injuries in the horses.

Contact

  • Sandra Bonow, PhD-student
    HBIO, Quantitative Genetics and Breeding