Seeking to remove a source of serious discomfort for horses - Veterinary Practice
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Seeking to remove a source of serious discomfort for horses

JOHN BONNER talks to Professor Bob Cook about his passion for a bitless bridle

EQUINE veterinarian Bob Cook
has spent a decade battling against
what he regards as a brutal
throwback to a Bronze age culture.
The struggle has been lonely and
frustrating but he now believes that
the equestrian world
may at last be ready
to accept his claim
that putting a metal
bit into an animal’s
mouth to control its
endangers the health
and safety of both
horse and rider.

Professor Cook
became interested in
the behavioural and
physiological effects of
the traditional bitted
bridle in the late 1990s
after retiring as head of
equine surgery at Tuft’s
University veterinary school in
Massachusetts. He was asked to
investigate an unconventional bitless
bridle which, through a crossover
arrangement beneath the horse’s chin,
applies pressure on the side of the head
rather than the delicate structures of
the mouth.

He became convinced that the
conventional bit is a continuous source
of serious discomfort for vast numbers
of horses. He has catalogued around
100 behaviours such as bolting, bucking
and rearing which he believes are
caused by the presence of this alien
object in the horse’s mouth.

“You can call these vices or negative
behaviours but I would argue that they
are neither, they are just a normal
reaction on the part of animal to its
feelings of fear and pain.”

More importantly, his research
indicates that a bitted bridle can have
serious ill effects on the horse’s ability
to breathe properly, particularly during the stresses of competition. So this
could be a significant causative factor in
up to 40 separate disease states
including exercise-induced pulmonary
haemorrhage, epiglottal entrapment and
dorsal displacement of the soft palate.

Moreover, he insists
that the fatigue
resulting from
asphyxia during
competition may
predispose a horse to
the sort of
injuries that can prove
fatal for both the
horse and its rider.

A 1952 RVC
graduate, Bob conducted research on
conditions affecting
the horse’s head and respiratory system at
three UK veterinary schools and at the Animal Health Trust before crossing
the Atlantic. He worked for two years at
the University of Illinois before being
recruited by the newly formed Tuft’s
school in 1979.

He was introduced to the concept
of the bitless crossover bridle by a
Californian horseman, Allan Buck, who
was selling a version that he called the
“Spirit bridle”. But the basic idea has
certainly been around since the 19th
century. There are also a number of
other designs which dispense with the
traditional bit including those devices
known as hackamores, bosals and

Yet these share the same flaws as
the crude technology originally
developed by the Scythian horsemen of
central Asia in about 5000 BC. Each is
used to cause pressure on the mouth or
the bridge of the nose – the crossover
design is the only one that controls the
horse without causing it pain, he says.

He carried out studies on the
impact of this basic bridle on horses
which showed signs of distress when
ridden using traditional tackle. Very
quickly he became convinced that many
of the clinical conditions that he has
seen throughout his career were a result
of the problems caused by the bit.

He made a few modifications to the
design which were patented in the US
and formed a company which sells this
kit through his website, . Similar
products are available from other
companies which have sprung up in
various countries around the world,
including the UK.

The idea of using bitless tackle has
been taken up with great enthusiasm by leisure riders in the US and abroad and
his website contains a large number of
unsolicited testimonials on the
beneficial effects that this simple device
has had on the experiences of the

This acceptance of the new
technology has, however, largely
resulted from word of mouth
recommendations – there has been
minimal support from his veterinary
colleagues in his campaign to change
the technology used to control their
client’s animals.

“The profession in the US and UK
has taken very little notice of the work
I have done over the past 10 years. I
don’t think they have woken up to the
fact that the bit can explain so many of
the idiopathic diseases that equine
practitioners have worried about for

“I can’t really explain why. I suspect
that most veterinary surgeons have
regarded the bit as a mystery which isn’t
really their province and have left these
issues to the horse owners.”

The attitude of the regulatory
authorities for equestrian sports has
been even less encouraging. The United
States Equestrian Federation insists that
bitted bridles are used by all riders
competing in all dressage competitions
organised under its jurisdiction
although, curiously, these are not
mandatory requirements for the cross
country or show jumping disciplines.


“I haven’t been able to persuade the US
authorities to even look at my data. You
can put it down to the conservatism and
tradition that is part of this world but
there is also a big dose of sheer
wooden-headedness,” he says.

Two recent developments have
given Professor Cook hope that
professional colleagues and the
competitive horse world may be ready
to accept his arguments for the benefits
of bitless bridles. The November 2009
edition of the Equine Veterinary Journal
carried a paper co-written with Daniel
Mills, professor of veterinary
medicine at the
University of
Lincoln, directly
comparing the
performance of
four horses ridden
with a
snaffle bridle and
his own design.

The study took
place at the US Certified Horsemanship Association
conference in October 2008 in which
the horses carried out two four-minute
exercises with the same rider, which
were viewed by an independent judge.
Two of the horses had never been
ridden with a bitless bridle before and in
the overall group there was an average
75% improvement in the performance
after switching to the new bridle.

Professor Cook hopes that now the
study has appeared in a reputable
journal, other equine scientists will be
persuaded to conduct research on the
behavioural and physiological effects of
the bit. Even more importantly, the
equine sports authorities have begun to
show a willingness to consider a change
in the rules.

In 2008, the Dutch equestrian
authority became the first association to
allow the use of the crossunder bridle in
its dressage and driving competitions
and the South African association
followed suit last year.

If the international body, the FEI,
and the larger national associations can
be persuaded to review their rules, the
bitless bridle could eventually be
permitted in all equine sports. A
proposal was being considered by the
US Equestrian Federation as this issue
of Veterinary Practice went to press.

“I don’t know whether they are
ready to accept this change just yet but
I am optimistic and feel we have
reached a tipping point. But even if it
doesn’t happen this time, I will still
keep hammering away. I am 78 and may
be getting on a little but I haven’t
finished yet.”

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