Horses in study showed dramatic fall in pain-related behaviors after going bitless

Fresh research reveals a raft of pain-related behaviours linked to bits
Fresh research reveals a raft of pain-related behaviours linked to bits

Sixty-six horses switched from being ridden with a bit to a bitless bridle showed dramatic reductions in 69 behaviors linked to bit-related pain.

Researchers Bob Cook and Matthew Kibler, in a study published in the journal Equine Veterinary Education, reported that the total number of pain signals for all the horses when bitted was 1575. When bit-free, just 208 were recorded – an 87% reduction.

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In total, 65 of the 66 horses benefited from removal of the bit.

The 87% reduction in pain signals with the removal of the bit showed that the bit was the main cause of pain among the horses, they said.

The pair said that when the horses were graded on the Five Domains welfare model, it was judged that, when bitted, the population showed “marked to severe welfare compromise and no enhancement”.

When bit‐free, the population was assessed as having low welfare compromise and mid‐level enhancement.

Cook and Kibler said metal bits, used since the Bronze Age, have been accepted as part of the furniture of horsemanship and not subjected to scrutiny until quite recently.

“As bits have been standard equipment for millennia, they are widely assumed to be indispensable and ethically justified.”

Bit usage was an elective and almost daily intervention in many horses’ working lives, they noted.

“Assessment of its effect on welfare is overdue.”

Welfare researchers David Mellor and Ngaio Beausoleil, in a 2017 paper, noted that horses showed clear behavioural evidence of aversion to a bit in their mouths, varying from the bit being a mild irritant to very painful.

They observed that evidence of aversion was available to all by comparing the open mouth, head tossing and restricted jaw angle of many bitted horses.

Cook and Kibler said their objective was to start answering six questions: What behaviours are caused by the bit? How prevalent are they? How many bit‐induced behaviours might one horse exhibit? Are they reversible when the bit is removed? Is a horse’s welfare improved by removal of the bit? Can a horse be controlled without a bit?

Their longitudinal, retrospective, questionnaire‐based study centered around each owner/rider’s assessment of horse behaviour, with and without a bit. In essence, it examined the number of behavioural signs of pain in each of 66 horses when bitted compared with the number of signs in the same horses when bit‐free.

The questionnaire was based on six years of feedback from 605 riders who had switched from a bitted to a bit‐free bridle. The feedback came from 106 yes/no questions about horse behaviour and signs of disease; and 10 questions addressing each rider’s feelings about riding.

Each rider completed it twice – once when bitted and again when bit‐free.

From the answers, the change in prevalence of 69 behaviours was identified, which formed the basis of the yes/no questionnaire put to the riders used in this latest study.

For the experiment, owner/riders from North America, Britain, Australasia, Austria, France and Holland had volunteered to take part.

Each horse served as its own control, in that its behaviour was compared before and after removing the bit. Ninety-six questionnaires were received, 66 of which were completed correctly and used for the study. Inclusion required that, that for each of the 69 behaviours selected for analysis, a yes/no answer must have been entered for both bitted and bit‐free periods.

The 69 behaviours included the likes of hating the bit, resenting bridling, a lack of control, going above the bit, muzzle rubbing, head shaking, lack of focus, pig-rooting, difficulty in steering, a stiff or choppy stride, tail swishing, yawning, head tilting, excessive salivation, bucking, difficult in mounting, failing to maintain a trot or canter, and stumbling.

The age of the 66 horses ranged from 3 to 24 years, with an average of 10. They comprised Thoroughbreds, Arabians, Warmbloods, Tennessee Walking Horses, Appaloosas, Clydesdales and others. There were 39 geldings, one stallion, and 25 mares.

Most were used for dressage (22), followed by pleasure (21), trail-riding (13), eventing and jumping (5).

All owners rode “English” style.

Twenty‐eight of the horses had been bitted for five or more years before making the change.

The time a horse had been bit‐free before the second assessment was undertaken by the rider ranged from just 1 to 1095 days. The median was 35 days and the average was 108 days.

The number of pain signals exhibited by each horse when bitted ranged from 5 to 51, for a median of 23. Once bit‐free, they ranged from 0 to 16, for a median of just two.

“The number of pain signals for the total population when bitted was 1575 and bit‐free 208; an 87% reduction,” they reported.

The reduction of each of the 69 pain signals among the 66 horses when bit‐free ranged from 43% to 100%.

Cook and Kibler said bit pain had a negative effect on proprioception – that is, balance, posture, coordination and movement.

“Only one horse showed no reduction in pain signals when bit‐free,” they said.

“The welfare of 65 of 66 horses was enhanced by removing the bit; reducing negative emotions (pain) and increasing the potential to experience positive emotions (pleasure).”

Discussing their findings, the pair said horses exhibit what is known as stereotaxis. They were innately programmed to try to evade the bit.

“It follows that the equitation mantra requiring a horse to ‘accept the bit’ is misconceived. Expecting a horse to accept an oral foreign body is a biologically unrealistic expectation.”

They said the improvements in behaviour following removal of the bit enabled inferences to be made about the aversive experience of bit‐induced pain.

“The improvements cannot be dismissed as ‘merely subjective’,” they said.

“Collectively, the behaviours were predominantly manifestations of pain experience, expressed by aberrant movements of the head, spine and limbs. They ranged from too little movement (e.g. stiffening, freezing) to too much movement (e.g. bucking, bolting).

“That some horses may exhibit a few aversions to the bit is widely acknowledged. That every horse is programmed to be averse to the bit and that aversions are numerous is not.

“The current study showed that at least 65 of 66 horses exhibited aversion to the bit and that horses have not less than 69 ways of exhibiting frustration, attempts to cope and efforts to avoid bit contact.”

The most prevalent pain index was “hates the bit”, a family of behaviours shown by 53 of the horses (80%). The full line in the questionnaire read: “Hates the bit, chomping, chewing or clenching the bit, grinding the teeth (bruxism), constant fussing with the bit, ‘busy mouth,’ evading contact.”

The second most prevalent index was “fright”, shown by 46 horses (70% of the population).

“It seems reasonable to assume that at least a quarter of the 69 pain indices imperil the safety of horse and rider.

“The data support the opinion that bit‐induced fear is the cause of many horse‐related accidents.”

The fourth most prevalent sign of pain when bitted was ‘lack of control’ (65% of the population).

“Its reduction by 86% when bit‐free questions the rationale of competition rules which mandate bit usage on the grounds that bits control horses.”

The authors said the 69 pain indices assessed in this study represented only a fraction of possible bit aversions.

“If, for example, a study was done on racehorses, it is predicted that many more bit‐induced, pain‐related indices (diseases and disabilities) would be identified.”

The pair continued: “The horse is motivated to avoid pain and seek comfort. Mankind has an obligation to promote positive emotions for the horse …

“Contingent on the absence of pain, a horse can probably derive pleasure from being ridden, similar to that derived from ‘play’ with [their own kind].

“Bonding between horse and rider seems optimal when rein cues are devoid of pressure, painless and proprioceptively supportive.”

Cook, who is Professor of Surgery Emeritus at Tufts University in Massachusetts, and Kibler, of Washington College, Maryland, who did the statistical analyses for the study, acknowledged some study limitations.

The case study population was not random and the assessors were not blinded. “Nevertheless, as recommended by current welfare science, the assessors were the people most familiar with the animals studied, having triple credentials as owners, caretakers and riders.”

Robert Cook, an equine veterinarian, has published many papers, mainly on diseases of the horse’s mouth, ear, nose and throat both in scientific and horseman’s journals. He is behind a style of bitless bridle which bears his name.

Behavioural assessment of pain in 66 horses, with and without a bit
W. R. Cook M. Kibler
March 31, 2018,

The study, published under a Creative Commons License, can be read here

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17 thoughts on “Horses in study showed dramatic fall in pain-related behaviors after going bitless

  • May 14, 2018 at 1:56 am

    Very good! What took you so long? Native American Indigenous people, the most versed in horse training/gentling
    We would appreciate the recognition for the discovering the oldest of the bitless method.

    Thank you

    Tj Bronson

    Nokoni Comanchi

  • May 14, 2018 at 2:38 am

    I want to make certain that people understand that bits were accepted as part of the furniture as they quoted because 3 reasons. Bitless contraptions were expensive and difficult to come by decades ago. Bitless horses were not easily controlled in emergencies and by people with little riding experience many of whom “rented horses” for town to town travel and last with so many horses not having proper training, humane training only came into being with the 70s and didn’t gain momementum until the 90s and yet had no real good methods of bitless items. Some elements like horse racing, barrel racing and the wider known classes had moments through their history where they experimented going bitless but most for safety went back. A bit is a danger if you are not understanding how to properly decide type, use, placement, size, and how to put on a horses head as well as riding lightly without conducting the ride by the bit. There’s no real training to most people on how to ease the pain, they just assume they have the correct idea, there is a painfree way to use bits however, it’s experts that need to pass these pieces of information down. Now having said this. I always suggest any rider use uncomplicated equipment however not knowing how they ride their horses training level or their bit knowledge even saying go bitless can have complications. I rode bridleless a lot, through my growing up years I rode mostly with halter and lead ropes, I used bosals and hackamores, however, the most effective tool I ever owned was a soft piece of yacht rope that I fashioned into my own bitless bridle switching the size from horse to horse. Bits do serve a purpose so while the assertion is all horses bitless remember those without any idea how their young horses handle or what new horses do need to transition carefully. I personally believe there are some horses and situations that have called for bits. This research is done differently however the bitless research was done by someone else in the 1980s and bitless only lasted a moment and people went back to bits for safety. Not because we’re a western shop do I say any of these things but remember it was a safety issue for many to have bits. I go back to the man who rode in hackamores since the 60s and his horse was startled in the 90s by a deer and his horse jumped in front of oncoming traffic, the man survived, horse did not. He never went without a bit again as he claimed he had a perfectly trained horse but no bit that day, he had no brakes. So there’s reasons.

    • July 2, 2018 at 3:19 pm

      When this horse got startled and the man was unable to stop it with a hackamore, to me this sounds like a hole in that horse’s training. You should never use a bit to stop a horse, cause it becomes a torture device. I learned a long time ago, if you can not stop a horse without a bit in it’s mouth, you have no business being on that horse in the first place, because that horse’s training was not finished!
      We ride all our horses at our guest ranch bitless! We ride in open terrain with non riders, beginners etc. and meet a lot of wildlife, like deer, coyotes, bears etc. Our horses are happy, responsive and capable of doing their job with hackamores and bosals!

    • July 12, 2019 at 2:04 pm

      I’d say he probably would have had no brakes on that day even if he’d had a bit in the horses mouth. My experience tells me that in a bolting situation a bit is utterly useless anyway. I’m not sure it’s a safety issue, I think its a confidence issue. People are afraid that they will lose control. Another aspect of the issue, I believe, is that people are not being taught to ride from the seat so much anymore. t least not in my country. It’s all about tight reins, and half halts to get the horse “working in frame.” The focus has changed so much that a pretty arched neck is all it seems to take to make a rider happy. I’ve seen hollow backed horses with necks arched by hellishly tight reins placed over a nice relaxed horse moving foward with a soft jaw and soft eye. The focus seems to have become all about flash and no substance.

  • May 15, 2018 at 5:44 pm

    I went bitless a long time ago when i read about the harm bits cause. It needs to be considered however that a badly fitted or severe hackamore can cause damage to the tip of the horses nose bone, and that strong horses are not safely controllable by softer options. Discussion, experimentation and sharing knowledge is very important to both horse and rider. We must be open to challenging old habits and assumptions. I gave up riding 10 years ago after a lifetime of horse keeping because I could no longer find it acceptable for human’s to enslave, sit on and control another being.

    • June 9, 2018 at 10:34 am

      If your approach to horses was to ‘enslave’ and ‘control’ then you should have given them up b4 you started. That is not how I have treated any of mine or other peoples horses.

  • May 16, 2018 at 5:19 pm

    It doesn’t say if these horses have had the correct dental work .Of course its going to hurt when you put a bit on a wolf tooth or a capped tooth or a rotten tooth. Also the article doesn’t say that these horses were chosen at random .They probably were chosen because they show aversion to the bit .I can tell you know that 65 out of every 66 horses is not the number that show signs of dislike towards a bit.

  • May 16, 2018 at 8:03 pm

    A major issue with the use of bits is that any damage done to the mouth is *unlikely to be seen* by the rider or indeed anyone else. Fitting tack to internal tissues of an animal will result in any lesions being hidden. Yes, the use of tack externally can also sometimes cause facial wounding, but this would be visible to anyone who cared to look at their horse. We only have to look at some of the natural horsemanship advocates who use fine rope halters to see scar tissue on some of their horses’ faces. Ideally, all tack should be sold with a labelling system, grading its use on the risk of harm to the horse. Yes, I think a typical hackamore would come out as quite severe, due to action of leverage. But sidepull and cross under bridles would be very mild. Indeed, where tack is made using broad gauge leatherwork, the ‘load’ of any pressure is spread widely over the horse’s face, so it would be very difficult to cause pain with such equipment. Where soft tissue areas are concerned (nasal cartilage) then tack should be fitted to avoid this area.

    The degree to which tack is actually used on the horse (in terms of touch and pressure applied) will relate directly to the degree of good training the animal has received. Much use of tack can actually be dispensed with where horses are taught to respond to verbal cues for changes in gait, speed and direction, instead of touch via tack and riders’ feet etc. Horses have perfectly good ears and brains and can soon learn to accept verbal cues instead of touch for aids. The problem of good humane training is that it remains extremely difficult to ask equestrians to do this. Most are wedded to aversive methods, subjecting horses to pain, or merely the threat of pain, for all of its working life.

    • July 12, 2019 at 1:50 pm

      I think also that the journey to upskill enough to perfect “good training” is years long. It has taken me several years to be confident enough in my riding and in my relationship with my horses to be ready to ride bitless. Also finding the right bitless system for each horse can be an expensive challenge. My youngster went through 3 different systems before we found one that he was relaxed in and responsive to.

  • May 18, 2018 at 6:41 am

    I just got a Dr. Cook bitless bridle. Im excited to try this on my older TB. He has a few of the issues you mentioned in this article. Looking forward to a happy ride for both of us.

    • May 22, 2018 at 3:48 am

      I ve been hacking my 2 Paso Finos for years in the bitless bridle. I would never go back to a bit. Any horse that can’t be controlled without a bit need more training not more bit!

  • May 18, 2018 at 7:55 am

    Ti Bronson: Thank you. Yes, I kick myself for taking so long to actually ‘see’ a foreign body in a horse’s mouth and ask myself what it does to a horse and what its purpose is from a rider’s point of view; two questions for which I finally know the answer. The bit does a great deal of harm to both horse and rider. Apologies for being blind-sided for so many years by my cultural inheritance. Bit-free riding long-preceded introduction of the metal bit in the Bronze Age. A looped thong in a horse’s mouth is less harmful than metal but is still a foreign body and contraindicated

    coltswesternshop: Bits are accepted because most of us have grown up with the assumption that they are acceptable. After 5000 years of usage, when competition rules were eventually written, bits were simply grandfathered-in without question. The bit came under scrutiny only in the last 20 years. Since then, published evidence shows it to be a safety hazard and inhumane. There is no good reason for using a bit and compelling welfare and safety reasons for not using one. A rule is not a reason. Fortunately, neither is it a law of horsemanship.

    Ruth Hawe@Truthawe: I am not aware of any published report of the peak of a horse’s nasal bone being fractured by an incorrectly-fitted leverage hackamore. Anecdotal reports of this probably occur because, in a specimen horse skull, the nasal peak becomes dried-out and fragile. It often breaks when the skull is mishandled. To your point about ‘strong’ horses, the most common reason why bitted horses become ‘strong’ and bolt is because they are frightened and panicked by the pain of the bit. A bit-free horse is far less likely to bolt in the first instance. Bit-free communication is more effective communication and less likely to be misunderstood by the horse. It is not a weak (‘soft’) option.

    Greenponies165: The article states clearly that the study population was not randomly selected, so you have a point but it doesn’t refute the main argument. It is extremely rare, in my experience, for a horse’s ridden behaviour to not improve when the bit is removed. This is to be expected because, as explained in the article, all horses are born to ‘move away’ from solid objects. A horse that does not exhibit inherited aversion to the bit (negative stereotaxis) is a neurologically damaged horse, e.g., a horse suffering from bit-induced ‘learned helplessness.’ One horse in my experiment showed no improvement in behavior when the bit was removed but continued to show aversion to the bit’s long-term effect. Please carry out an experiment and tell me what your number is.

    Greg Glendell: I agree. As you say, “horses have perfectly good ears and brains.” Thank you for reminding us that horses love ‘no-touch’ training.

  • May 19, 2018 at 2:34 pm

    Nothing is black or white in life. Bits can be torture instruments or helpful tools, it is all in the application. Horses ridden with bits typically frame up and collect much better better, get security from the riders hand, build confidence and stumble much less cross country. It requires a skilled rider with subtle hands to achieve this. With an unskilled rider, bits can jerk on their mouth, cause pain in mouth and teeth and the horse will resent the rider. But, riding bitless is not going to fix any unskilled hands of a rider.

    • June 13, 2018 at 11:04 pm

      A skilled rider with subtle hands succeeds in using a bit only because he/she uses it with the very lightest and transient of touches. The less a bit is used the greater the success. A bitless option is the ultimate in this logical progression. It prevents the unskilled rider from inflicting unintentional pain and its dangerous consequences.

  • June 7, 2018 at 3:06 am

    what about driving a horse or pony bit less, This is not allowed on the road for insurance ressond

  • June 13, 2018 at 11:09 pm

    I recommend that you change your insurance

  • September 18, 2021 at 8:00 am

    I enjoyed reading this article. However, I have a few critiques. 1) It does not state whether or not the horses were chosen at random. 2) The transition from bit to bitless can not be rushed or forced onto the horse all at once. If your horse has been riding in a bit his whole life then all of a sudden changing can be dangerous. Instead of going from bit to no bit, try going from bit to smaller bit, work with him to respond well in the small bit, and then move to bitless. Doing the same thing, it takes time and patients, work with your horse, groundwork is a great way to safely work with your horse.
    Horses are amazing creatures, I am so thankful that God created them. They deserve respect and kindness. There are a lot of things I wish I did differently when I first got my horse. I am older now and have gained more knowledge and realize that some of the things I did to her were not ok. I am trying to my dad about the whole “bits hurt horses” thing but he was raised that the pain from the bit is from the rider not the bit.
    ~ Bri


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