Bleeding, breakdowns and sudden death: An interim solution for Californian horseracing?

A racehorse in Germany competing without a bit. Dr Cook notes the sealed lips, the lack of drooling and the loose rein.
A racehorse in Germany competing without a bit.

The problem of catastrophic breakdowns in US racing is an extreme example of an international problem that has existed since horseracing began.

One of the foundation sires of the Thoroughbred Stud Book was charmingly named “Bleeding Childers”. He never raced. He was retired to stud with the prefix “Bleeding” deleted, becoming champion sire as Bartlett’s Childers in 1764.

Fast forward to the early 1970s in the USA, when Kentucky racetrack veterinarian Dr Alex Harthill was the first to use a diuretic, furosemide, as a pre-race medication for bleeding from the nose. The bleeding didn’t stop but, perhaps because of the weight advantage, some medicated horses won races. The use of furosemide (Lasix) quickly became popular and – in 1974 – its use was officially permitted in Kentucky. All 38 racing states subsequently followed suit. Since then, two generations have regarded permissive medication as the norm.

In 1974, I published an article in which I concluded, after using a rigid endoscope to rule-out the nasal cavities, guttural pouch and throat as the location of the hemorrhage that, when a racehorse had a “nosebleed”, the blood was likely to have originated from the lungs. This was news at the time. Soon after, using a flexible endoscope, Dr Richard Pascoe confirmed this conclusion.

Since 1999, hundreds of thousands of recreational riders, worldwide, have switched their horses from bit to bit-free.

By 1988, I had come to consider “bleeding” as an airway obstruction problem. Only in the last 20 years have I perceived that the evidence points to the bit as the ultimate cause of the obstruction. At liberty, a horse runs with sealed lips. One swallow prior to running, locks-down the soft palate on an immobile root of tongue. A bit breaks the lip seal; during strenuous exercise in any horse sport, the soft palate may elevate at each intake of breath; the airway becomes obstructed, and the lungs are bruised at every following forced breath. As galloping horses take at least two breaths a second, suffocation can quickly cause fatal waterlogging of the lungs. A bit can kill in seconds.

Since 1999, hundreds of thousands of recreational riders, worldwide, have switched their horses from bit to bit-free. Nevertheless, in most horse sports and all of horseracing, a bit is still mandated. Please do not dismiss a bit-free solution for racing and all the other disciplines for which a bit is mandated without considering the evidence below.

The trouble is we have all grown-up with the mistaken belief that bits control horses. It took me 40 years to open my eyes but, in the last 20, I have realized that the bit is the most common cause of lost control and many accidents. Bit-free horses are safer to ride and more controllable without a painful foreign body in their mouth. Jockeys and exercise riders will signal more effectively with a bit-free rein and will be less likely to be injured. The evidence indicates that bit-induced pain, negative behavior and airway obstruction triggers a catastrophic cascade of accidents, breathlessness, bleeding, asphyxia, breakdowns, and sudden death. Search the internet for “negative pressure pulmonary edema” (NPPE) to understand the mechanism.

Blood in the trachea of a racehorse after hard exercise, as revealed by endoscopy.
Blood in the trachea of a racehorse after hard exercise, as revealed by endoscopy. From the article Lung bleeding in horses: What do we know so far? (2016).

When bit-free, horses can breathe freely. Such racehorses would, in my opinion, no longer be at high risk of “bleeding” and sudden death. Similarly, catastrophic breakdowns due to premature fatigue from a shortage of oxygen would be less likely to occur.

Chain of thought
  • Catastrophic breakdowns and sudden death in racehorses are most prevalent in the USA, where medication adds to the problem
  • The general public is now increasingly aware of animal’s welfare needs; attitudes have changed
  • Public perception could result in USA horseracing being banned
  • In my opinion, the root cause of this group of problems is the mandatory use of a metal bit; an invasive tool developed in the Bronze Age.
  • The problem can be solved if each of 38 US racing jurisdictions repeals the mandatory bit rule and allows bit-free racing
  • But even if only one state was to do this, the effect would I predict – by its convincingly favorable results – set a compelling example for others to follow
  • The state most likely to pass legislation banning horseracing is currently California

California’s Horse Racing Board faces a serious situation but it is not without remedy; if it does nothing, horseracing in California could be banned. Once banned, the task of reversing the ban will be immensely more difficult than updating a rule of racing

California’s Horse Racing Board could immediately avoid the demise of racing in the state by announcing a statement of intent to repeal the mandatory-bit rule

By so doing, California could lead the way for the USA and for horseracing worldwide. As a result, California could enhance the popularity of the sport and do much for its social license.

Seen this way, the present crisis offers a golden opportunity.

Santa Anita.
Santa Anita. Bob Cook argues that waiving the mandatory-bit rule for a probationary period at Santa Anita, could perhaps earn California horseracing the necessary “breathing space”. © The Stronach Group
Rule changes take time

The snag is that a rule change will take time to be even considered in the first place, then to be drafted, discussed, agreed and finally activated. Such steps could take years to complete. Unfortunately, the climate of public opinion is such that horseracing may not be given time. The Breeder’s Cup takes place in a few weeks. If only one catastrophic event should occur, horseracing in California could be shut down. A domino effect in other racing states could follow.

An interim step, if agreed in principle by the California Horse Racing Board before November, could forestall the demise of horseracing and earn time for a permanent solution to be tested and developed. Without drama, the Royal Dutch Equestrian Federation smoothly introduced bit-free dressage some years ago, using a probationary and sequentially class-limited rule change.

If the California Horse Racing Board agreed in principle, before the Breeder’s Cup, to waive the mandatory-bit rule for a probationary period at Santa Anita, starting sometime in 2020, this indication of intent could perhaps earn California horseracing the necessary “breathing space”.  It would enable a bit-free testing program to be initiated, first for horses in training and then for racing. Evidence could be obtained concerning the practicality and safety of bit-free racing. The question to be asked (aka the hypothesis to be tested) is “If bit-induced suffocation is prevented by removing the bit will this significantly reduce the prevalence of bleeding, breakdowns and sudden death?” Currently, existing rules prevent the necessary trials from being conducted.

In the long term, solving the bit problem in one state could solve it in all states. It could eventually release US horseracing from the death-grip of the Lasix problem, the therapeutic medication problem and even the performance-enhancing drug problem. Bit-free racehorses will, I predict, out-perform bitted horses and “assisted” horses of all stripes. The incentive to medicate will be neutralized and, with regard to Lasix, the purported excuse for its use would be eliminated.


Further articles about bitless riding
Bits can suffocate racehorses and cause sudden death, suggests professor
The unpalatable truth: Bits are linked to a host of behavioral and breathing issues
What does a bit do to a horse and rider?
Horses in study showed dramatic fall in pain-related behaviors after going bitless
Unintended consequences in preparing the “big horse” for the “big day”
70 reasons for not using a bit: Your horse may thank you
Chomping at the bit: Have we had it wrong all along?
A truly fascinating bit of bit research

Articles 1 and 3 were written for non-veterinarians. Article 2 is a peer-reviewed publication in the Journal of Equine Veterinary Education. A free abstract is available online. Item #4 is the video of ‘Horse South Australia’ professional development event.

  1. Cook, W.R. (2014): “What causes bleeding?
  2. Cook, W.R. (2015): Bit‐induced asphyxia in the racehorse as a cause of sudden death
  3. Cook, W.R. (2019): Horsemanship’s elephant in the room: The bit as a cause of unsolved problems affecting both horse and rider
  4. Mellor, D.M. (20198): “Sport Horse Welfare and Social Licence to Operate”


Dr Robert Cook

Bob Cook, FRCVS, PhD, is Professor Emeritus at Tufts University, Cummings School of Veterinary Medicine, North Grafton, MA, USA.

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