Tuesday, November 11, 2014

Rider Enduced Changes in the Horse

The old adage, form begets function surely applies to our horses.  While horses can perform beyond their form or breeding they excel best when used for the purpose for which they were designed.  This is why Clydesdales pull the Budweiser hitch and Arabians do the Tevis cup and not vice versa.

What shouldn't surprise us though is function also begets form.  Our horses will reflect the use that we put them to.  In veterinary medicine we see specific injuries and performance related issues associated with specific disciplines as the horses are used.  It's a natural extension of our relationship with our horses.  You cannot ride a horse to any extent without changing the way that horse's body in some way. This isn't always bad and it happens in all walks of life.  Many of our bodies reflect the work that we do unless we work hard to avoid that.  Asymmetrical development in the dominant arm of any person that preferentially uses one arm for the majority of their work is a good example of this.  Unless they consciously build muscle in the opposing arm, the arm being used most will be the strongest.  Our horses are the same.

What I'd like to talk about today is the way we can affect change in our horses for both good and bad and how we can avoid some of the pitfalls of poor muscle development, braces, and other injuries that can shorten or limit the useful life of our horses. Eventually I will write an entire book on this subject as it is one dear to my heart so paring it down to fit into a blog post has been difficult.  There are far reaching implications and a plethora of details and minutia to be debated in this topic.  Let's start with just a few.

"Saddleback" is a term that refers to the hollowing of the top line behind the shoulders and eventual sinking and swaying of the back after years of service under saddle.  Common thinking in the horse world is often that this is a phenomenon of old age and is unavoidable.  To some extent that is true.  As a horse ages and is subject to heavy loads it's back will wear and break down.  Unless the horse exercises the muscles responsible for rounding and shaping the back, gravity and work will eventually win and you will see a pronounced sway.  Conformation of the horse definitely plays a roll in this.  Horses with long backs and laid back shoulders will often carry themselves with poor self carriage.  Self carriage does not necessarily come natural to the horse and you can see "saddleback" on a horse that never carried a rider.  It's common in cart horses that push with their shoulders instead of rounding their backs to push through their entire bodies.

While "saddleback" can be a natural process of aging, poor riding habits can compound this problem. Just like good posture in people, proper self carriage in the horse must be cultivated. A horse that is allowed to carry himself in a sunken and hollowed way will advance into saddle back quicker than one that is in a conditioning program designed to keep those muscles functioning.  Just people, some horses will need more time in the "gym" toning and shaping those muscles while others will seem to be toned and shaped without added work.

I have a horse that tends toward saddle back.  He has high withers and long sloping shoulder and as he has aged this problem is getting worse.  This also happens to be the horse that I do the most back country and trail riding with.  He has a long ground covering walk that I enjoy riding but he tends to go hollow when in this gate.  If we spend too much time out on the trail and not enough time doing calisthenic exercises encouraging rounding through his top line this problem gets quickly worse to the point of effecting my saddle fit.
So how do you encourage your horse to round and lift and shorten his back to build those top line muscles?  Transitions and work on soft feel help the horse to bring his back up.  The time that we spend on the Cowboy Dressage court is incredibly valuable to toning and shaping his muscles and top line.  Transitions done with soft feel from working walk to free walk and working jog to free jog ask the horse to repeatedly shorten and then stretch those muscles.  It's like doing leg bends at the gym.  It focuses the energy of the ride up through the top line and encourages self carriage combating the dreaded "saddleback".

"Oh No Muscle".  This is a muscle that I am very familiar with in my patients.  Anytime I need to do an intravenous injection into the jugular vein and place my left hand on the horse's neck to raise the vein I can tell exactly what kind of hands the person riding the horse has.  The "Oh No Muscle" is the over development of the muscles on the bottom of the horse's neck.  They run on each side of the neck and form the jugular groove and are responsible in part for flexing the neck and moving bones in the throatlatch area.  Over development of these muscles will give a horse a "ewe" neck appearance that may be completely secondary to use and not due to conformation at all.  In general, when I put my hand on these horses to raise the jugular vein their first response is to raise the head and neck and flip the nose up.  These are your classic head tossers and they tend to ridden with both a tie down and gag type bit to discourage the behavior.  These are horses that are long accustomed to bracing against pressure.  Better than 50% of the time these horses will also have damage to bars of their mouth from long standing bit pressure.
 This habit is tough to break in a horse even with a rider that has good hands.  The deep seated bracing and flipping of the head are so ingrained as a defense mechanisms these horses will say "Oh No!" before anything is even asked of them.  They generally start flipping their head before I even touch them with a needle and many of these horses will engage in this behavior in the pasture flipping their head at flies, other horses, or any stimuli that they classify as irritating.

The best cure in this case is prevention.  This is a case of a horse learning to push against pressure as a defense mechanism.  If there is never pressure to push against the horse cannot develop this habit.  Pulling relentlessly on young horses or even older horses that are being forced to preform in a way that they are not properly prepared for will develop this habit.  There are shelves of tack devices to counter this human produced equine behavior.  Tie downs, martingales, cavesons, draw reins, gag bits, correction bits, etc are all developed by folks trying desperately to remedy this behavior pattern as well as establish "proper" headset.  There is only one way to be sure that the "Oh No muscle" doesn't raise it's ugly head on your horse.  Soft Feel.  That's the only sure fire, 100%, always going to work gadget and you can't buy it in any tack store.

Bar damage is the last thing I would like to cover in this blog and this is a tricky one to address.  As I mentioned above, I'll often see bar damage in horses with a big "Oh No" muscle but it can be much more insidious than that.  Bone spurs on the bars of the horse's mouth will often go unnoticed by the rider and have largely been undiagnosed in horses until more recently.  Research has been done recently examining the differences in jaws from horses that were ridden and those that were feral examining the changes that we see in our domestic horses.  In jaw bones collected from slaughter houses from horses that presumably spent time with a bit in their mouth we see thickening of the bars, bone spurs similar to shin splints, hair line fractures, roughening of the periostium due to continued stimulation of bit contact. Without doing extensive comparrisons of horses across disciplines and with good information on the type of riding and type of rider they were carrying all we can do is extrapolate about the damage and potential damage that we are doing to our horses with irresponsible bit use.

The advent of widespread availability of digital x-ray technology is going to allow us to better examine the jaws of horses that are experiencing signs of resistance or bracing to the bit.  Physical examination can provide good information as to the health of the horse's mouth and state of the bones of the jaw.  I assess the bars on every horse that I float and can usually tell if a horse is having trouble with the bit.  I find bone spurs, thickening and roughening of the surface of the bars through palpation of the bars.  You can generally tell if the horse is stiff to one side over the other or has a tendency to fight the bit.

Often a horse with bit wear on the teeth has been attempting to alleviate undue pressure on the bars by attempting to hold the bit in his teeth.  When I see a horse with rounded premolars they generally will have thickening along the bars as well.  In my practice I would say that in general I see the most bar damage associated with snaffle bit use, gag bit use and horses that are asked for "collection" or head set in the show ring.  These are the horses that seem to experience the most pressure on their bars.  This is in no way a scientific observation but only a personal one based on the hundreds of horses that I evaluate in my practice each year.

Every horse's mouth is a little different.  Some big boned horses naturally have very thick and rounded bars and these seem to hold up well to carrying a bit.  Other horses have very thin delicate bars and these are generally at greater risk for damage.  Young growing horses that have very active periosteums in the jaw and are experiencing the growth of adult teeth are especially susceptible to damage from excessive bit use.

Mitigating this damage relies on protecting the horse's mouth and respecting it.  Hard mouthed horses are not born, they are made.  While there will be variation between horses depending on bar conformation all horses have to potential to feel and respond to very light stimuli on the bars of the mouth.  Building responsiveness in a horse by rewarding try and soft feel will help teach a horse to be responsive and "soft mouthed" without undue damage.

Allowing young horses to mature prior to bitting is also a good practice to minimize damage to the bars.  This is one of the things I love most about the vaquero tradition that relies on the bosal saving the sensitive mouth for advanced training.  Once the horse is carrying a bit he has advanced far enough in his training to be able to respond with very slight pressure on the mouth.

But, a good horseman can definitely ride a horse in a bit without causing undue damage.  I think of a young woman in my practice with a 8 year old horse that she has been riding in the snaffle bit for 5 years.  When last I floated that horse his bars were pristine.  That is a woman with beautifully soft hands.  I don't advocate the widespread use of bitless bridles to irradicate bit damage.  I advocate the widespread education of the hands of horseman that use the bits to improve timing and feel and mitigate damage before it happens.

There are many, many more examples of how our riding choices and uses of our horses affect their bodies.  I will revisit this topic at a later date to discuss some of the other issues that we see that are affecting our horse's physical and mental well being.