03.01.08

Dr. Teskey on nerving the navicular horse

Posted in Horses for the horse crazy at 3:08 pm by petArtist Cmoses

Reprinted from Dr. Tomas Teskey, DVM, with more links and medical-caliber photos found here; from the barefoot website naturalhorsetrim.com
Dr. Teskey is author of The Unfettered Foot: A Paradigm Change for Equine Podiatry Email Dr. Tomas Teskey

I was recently approached about consulting with a dressage stable owner and his plans to purchase an eight year old Swedish warmblood mare that had been diagnosed with navicular syndrome. He was interested in just using her as a brood mare since she was approaching “middle age” and the lameness problem was “incurable”. I was informed that her fantastic breeding and records in the show ring would likely make her foals highly desirable. The previous owner was selling the mare because she was unable to afford the necessary surgery that the mare needed to remain sound and usable. Her veterinarian was planning on performing a digital neurectomy on both front lower legs of the mare and has been in touch with this potential new owner about following through with the necessary procedure. This stable owner decided to purchase this unsound eight year old mare at a much reduced price, and has been in consultation with me from the time she stepped foot on his property. This was six and a half months ago. He has also been in contact with the referring veterinarian over this time and has kept her informed of our progress in treating this mare for her diseased front feet.

One of his original questions for me before I met him or this mare, “Crystal”, was as follows:
He writes in his email, “I’m hoping you can help me out. I’ve just purchased a broodmare with navicular. Would it be possible for you to provide me with some information before breeding this mare? I looked at the x-rays with the previous vet and she suggesting cutting the nerves on this mare and didn’t understand why the previous owner hadn’t done it sooner. What are the pro’s and cons of this nerve cutting? Thank you for your time.”

My response to him four months ago was as follows, and with his permission I am sharing this information with any and all of you who would like to explore with me what has traditionally been happening with these horses and why it is high time we reevaluate the way we think about and treat these very common hoof problems:

The procedure you are referring to is known as a “neurectomy”.
[nerving] is known as a “neurectomy”. It is generally
performed on horses that have had chronic pain problems in
their feet, most notably “navicular” problems. The horse is put under
general anesthesia and the digital nerves on both sides of the lame
leg AND the more sound leg are isolated and cut–most often a section
of the nerve on both sides is removed and the ends “capped” with the
leftover nerve sheath. The reason that both legs are surgicated is
because most horses end up quite lame in the leg opposite the
originally lame one if it is left intact.
Thus, one can easily appreciate that even though a
horse only shows lameness in one of the forelegs,
both are affected in a horse with “navicular” disease
or “navicular” syndrome. The result of the surgery is that the horse
loses sensation from this point downward and is unable to feel the
pain from the diseased foot anymore. Usually the limping that was due
to the pain in the area goes away and the horse can continue to be
used.

The horse is thus returned to “soundness”. This procedure costs
anywhere from $250 to $1500 depending on where it is done and who
does it. It is “effective” for around one to two years–sometimes not
that long, sometimes longer, but all of these horses eventually
regrow some nerve connections and regain sensation of the area that
was originally desensitized. The lameness then returns and the
procedure can be repeated at that time to keep the horse sound. As
you can easily see, this procedure addresses only one thing for the
horse and the owner: the head bobbing lameness.

There are some very real and potentially devastating negative side
effects of digital neurectomies in horses. Often times the raw ends
of the nerves become irritated to the point of developing extremely
painful nerve tumors called neuromas, leading to further surgeries to
remove them. Other times, the digital arteries and veins that lie
immediately parallel to the cut digital nerves become scarred and the
resulting stagnation of circulation leads to foundering of the worst
degree. Localized infections, scarring of tendinous and ligamentous
structures and unsightly swellings are also common. Thus, a procedure
designed to provide temporary relief from a widely misunderstood type
of lameness often leads to further pain, loss of use and early death
for these affected horses. Performing these surgeries is severely
disruptive to the horse’s lower leg anatomy, physiology and energy
patterns, and commonly leads to irreparable damage.

“Navicular” problems, often referred to as “heel pain” or “caudal
heel syndrome” start presenting symptoms in horses as young as two
and three years old when their hooves are either allowed to overgrow
into a deformed shape, and/or their feet are shod at this young age. The
still-developing coffin bones and sensitive inner hoof structures are
surrounded, constricted and over-pressurized by the progressively-
deforming hoof capsules, starving them of vital movement and
circulation, yet forcing them to attempt to function and survive in a
physiologically stagnant state.

Older horses are also plagued by what is termed navicular disease
and innumerable other hoof problems when their hooves
also succumb to deformities in structure and stagnation
of function. These lamenesses occur after longer periods of what is
traditionally thought to be the “best hoof care possible”. When
this “best hoof care possible” consists of infrequent trimming and/or
shoeing, it is no mystery, but rather a highly predictable and
physiologic certainty, that these horses will suffer from hoof
deformities and possibly debilitating lamenesses. “Killing me softly”
takes on new meanings when it comes to the effects of the steel
horseshoe on our equine companions.

Given that all of these “navicular” horses can be shown to have
deformities in the outward appearance of their hooves, it would seem
logical to direct our efforts towards improving their abnormal hoof
form, reversing the trends that are causing these deformities and
provide for the horse a situation that promotes good hoof form.
Cutting the digital nerves in these horses provides absolutely
nothing that is honestly therapeutic for them. It is a medically
unsound procedure, but it is prevalent in our modern day “use and
abuse” philosophy of keeping horses going– doing this in a day and
age where we now have an excellent understanding of why these horses
end up with “navicular” pain is totally unnecessary and irresponsible–
there are no sound medical reasons to perform these nerve surgeries
with the reckless abandon they are.

These procedures are an excellent example of how simple
ignorance of proper hoof form and function allows horse owners
and their veterinarians to perform them. Terms like
“salvage procedure” have become widely used to describe such
procedures that prolong the useful life of the animal strictly for
the human’s monetary benefit. Addressing the real problems of the
deformities in the feet and how to reverse them with proper trimming
and lifestyle will win out as the only acceptable alternative for
these animals and their human stewards, and the true salvage in terms
of the lives of horses will be realized.

Performing digital neurectomies on heel-sore or foot-sore horses
promotes further degeneration of the entire lower leg and hooves in
these animals, because it disrespects and disallows what the entire
animal needs to achieve a more proper hoof form and normal function.
Instead of cutting the nerves to a part of the horse’s anatomy and
achieving a completely false sense of “soundness”, we are
alternatively able to nurture these unsound horses and their deformed
feet to attain correct hoof form and thus proper and vital
physiologic function. Natural exfoliation, vital mechanical hoof
movements, energizing sensation and exquisite protection are just a
few of the important functions horses’ hooves need to have, and this
is precisely what they achieve with proper hoof care. This leads us
and our horses on a direct path to an honest soundness, far outpacing
conventional western veterinary medical techniques and promoting the
physical and psychological health of the entire horse, rather than
disrupting a part of the horse’s vital anatomy, which only leads to
further deterioration, loss of use and early death.

As it is improperly trimmed and/or shod horses that are the ones
affected by “navicular syndrome”, we know that promoting sound,
naturally shaped hooves along with adequate movement on firm terrain
is essentially a life-promoting and life-saving, honestly therapeutic
form of treatment–it is this type of treatment I will prescribe for
horses that I tend to, as it is the only treatment that respects the
nature of the horse. Drugs such as isoxsuprine, nitrous oxide,
nitroglycerin, phenylbutazone and flunixin meglumine do nothing to
improve the deformed feet in these affected horses. Eggbar shoes,
reversed shoes, special pads, natural balance shoes, wedge pads,
impression material, shoes with rails and/or frog inserts, or any
other artificial appliance attached to the bottom of the horse,
cannot possibly be honestly therapeutic for horses with navicular
problems or other hoof ailments. It is a physiologic impossibility;
they can only serve to further the deformities and damage to the
horses to which they are nailed, perhaps prolonging the development
of further, inevitable symptoms until years down the road, but still
furthering the damage all the while.

There is not a single case of a horse with severe “navicular
disease” that has been cured by the application of an appliance
to the foot. Cured, and/or sound, would be defined as a
horse that is able to walk, trot and run at liberty on their
own feet in a soft environment with animation, impulsion and
without lameness. It is the promotion of natural hoof form and thus
proper hoof function which allows horses to heal from the insults
previously afforded them by improper trimming, shoeing and/or
lifestyle, and they heal remarkably well if we respect their
fascinating anatomy and its wonderfully simple physiology. Providing
this option to horse owners when they are faced with whether to pay
for a “salvage procedure” or provide for what their horse honestly
needs is what the natural hoof care movement is about. These are life
and death situations for our horses and it saves horses’ lives every
day.

It is ironic that honest, well-intentioned people across the land are
spending their hard-earned money on treatments that are making their
horses more unsound and more unusable in the long run. Terms such
as “therapeutic shoeing” or “corrective shoeing” will soon be exposed
for the oxymorons they are, and interested parties such as insurance
companies and horse-leasing operations will soon question such
practices, and will not stand idly by while shelling out millions of
dollars to pay for such appliances and other “treatments” such as
neurectomies that only serve to worsen the conditions of the animals
to which they are responsible. Alas, this is the age we now live
in… an age of transition for ourselves as well as our horses. Our
responsibilities are great, the knowledge is there, and it is coming
to an area near you.

Tomas Teskey D.V.M.

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