New research: How horses perceive bits and bitless bridles

There are many studies about the welfare implications of bits, and bitless bridles. But how do you study such a diverse topic? What parameters do researchers choose? Do you look at average or maximum rein tension? Do you focus on all stress behaviours including tail and ear behaviours and body posture or only at specific facial expressions? Was there a bit fitter present who checked whether the bits used in the study were actually fitting the mouth of the horse correctly? In my search through the grey foggy world of different bridles types I encountered a really interesting scientific article called: “Horses’ voluntary acceptance of rein tension with various bitless bridles compared to a single jointed snaffle bit” that I’d like to discuss here.

Facts or opinions?

When thinking about animal welfare I think it is really important to discriminate
between facts and believes (our feelings and emotions that arise when
confronted with certain stimuli). I also believe that as a responsible
caretaker of our horse or perhaps our other kept animals,  we have a duty to always keep on searching for new facts on how to improve the quality of life of your kept animal.

This requires us to be curious, openminded, perfectionistic and critical, but also to realize that we do not know all the facts, nor ever will, probably. The truth is often somewhere in the middle, and perhaps different in different situations. In this uncomfortable grey area where every advantage has its disadvantage you as owner will have to make quite often an uninformed decision. This means that we should be really careful and humble in how we express our opinions and experiences because they are often nothing else but our perception of that grey foggy world. 

 Research problems

Personal opinions and biases can also colour research tests and their outcome, though. When comparing bits to bridles, often horses in extreme sports like racing or high
levels of jumping and dressage are studied. But are these situations representative for the common recreational rider and their horse? The recreational rider has often less expectations of their horse but at the same time is often lacking the experience and skills of the professional rider. Not to mention the different types of horse breeds that are used for different types of sports and studies. You can also wonder how to make a fair comparison between bit and bitless bridles when the type of bridle used seems highly confounded with the type of training method, type of breed, type of housing,
believes of the rider and the earlier experiences that the horse and rider had
with bits and bitless bridles.

Pressure test

A recently published article seemed to have avoided these all too common pitfalls: “Horses’ voluntary acceptance of rein tension with various bitless bridles compared to a single jointed snaffle bit” from 2019, written by M. Kubiak, A. Voght, H. Sauter, J.W. christensen, U. Koning von Borstel.

These scientists wondered how horses perceive the pressure from different bitless bridles compared to the regular snaffle bit bridle.  In this study 21 leisure and riding school horses of different breeds were tested with different types of bridles:

LG bridle
Side pull
Dr Cooks bitless bridle
Fred Rai Rope (bosal)
Conventional rope halter
Bridle with single jointed snaffle bit

A rein tension meter was attached to the reins, which were fastened 10cm above the withers to a anti roll bar attached to the girth. To simulate the riders hand. The rains were fastened in such way that the horse could hold their forehead 5 – 10 cm in front of the vertical like it would while riding. Horses were lured with food to stretch horizontally – downwards against the reigns while standing still in a stable. The maximum amount of pressure the horses were prepared to put on the reigns in turn for the food item was measured. The test was repeated for each horse and bridle 3 times a day.  On for each horse, three subsequent days.

Test results

The results show that regardless of bridle type, the type of breed had an effect on the level of pressure the horses were willing to accept by the bridle. Cold-blood pony types applied significantly higher maximum rein tension (µ 43.9N) compared to horses of warm (µ 29.0N) and  hot typed breeds (µ 28.6N). Age and repetition did not influence the amount of pressure the horses were willing to accept by the bridle.

When looking at the effect of the different types of bridles, horses applied similar maximum amount of pressure on all bridles (µ 32.4N– µ 38.9N) except for the side pull bridle (µ 26,7N). Meaning that horses seem to perceive a higher level of discomfort when similar pressure levels are exerted on the reins of a side pull bridle compared to the other bridles. This might be explained by the fact that the type of side pull bridle chosen contains a stiffer and thinner nose band which makes it less comfortable for the horse.

To conclude, similar pressure is required for both bitless or bitted bridles (except for the side pull in this experiment) to get the same response from the horse, since similar amounts of reign tension seems to result in similar levels of discomfort by the horse (which is the learning cue in negative reinforcement training. A training method which is commonly used in most types of horse training). Besides the individual differences amongst horses also horse breed seems to affect the perceived pressure sensitivity. Interestingly enough horses do not seem to get used to the maximum amount of rein tension over time: they will always try to evade it as much as possible.

Where to go from here?

In my enthusiasm I shared this article with my sister wondering about her opinion. When we talked on the phone later that day she said. “So funny, people who are in favour of bitted bridles will use this as proof that a bit is not more harmful compared to bitless bridles. While People against the use of bits will use it as proof that bitless bridles are just as effective as bridles with bit”. I laughed along but felt torn between the two camps. . I just wanted to lift a bit of the grey fog, not to feed more ammunition to both camps. Of course this article does not answer the question about whether we should train with bit or not. But the interesting thing is  that these researchers took the owner or trainer effect out of the equation and really tried to look at the perception of the horse without our human assumptions.

After writing this article I find myself wondering whether it actually matters how much pressure we can put on a bridle for the same level of discomfort. Because don’t we all increase our rein aid, when the horse is not listening, till the horse decides it is better to do what we ask then to endure more discomfort? Isn’t that the whole idea behind negative reinforcement? Is there a welfare issue when we use a more severe bridle in combination with really soft aids? Is perhaps negative reinforcement in itself then perhaps the problem and not the bridles and other tools we use? And how much discomfort is acceptable? With these thoughts in mind I realize I am back where I started. In the grey foggy world where no simple answers exist. But perhaps the veil has lifted a little and I am able to see a bit better trough the mist of entangled facts and believes.

I dare you as horse or animal care taker to step outside your comfort zone, and walk with me into the world of grey fogginess and find your way by disentangling facts, experiences and believes while facing your uncertainties.