THE NATURAL HOOF SHAPE & RHD

by David Farmilo
Accredited Master Farrier, Oakbank SA
PH 0418 835 186
www.horsefarrier.com.au

To quote Dr Doug Butler in his book The Principles of Horseshoeing, “The hardest thing a farrier has to deal with is making his hands do exactly what his mind and eyes are telling them to do.” And indeed it seems that as soon as some farriers pick up the sole knife or the nippers or the rasp, from there on the hoof takes on a completely different shape from that which was first intended.

IF we use the rasp too heavily when dressing the front of the hoof and IF, instead of just correcting the thickness at the toe, we allow the rasp to continue the stroke to go past the toe section and along the side walls, the hoof will have a correct toe but narrow sides and the wrong shape hoof. When rasping the toe it is important to do just that, and not allow the rasp to travel around the side of the hoof. It may help to mark the outer limits of the toe with a black marker pen to stop that rasp heading around the sides of the hoof. We should always work towards maintaining a parallel hoof/pastern angle and controlling any flares; to achieve this we need to develop an almost surgically light hand with the rasp. Use a good sharp rasp and use it very lightly – don’t grip the rasp, just hold it between thumb and forefinger, alternating the strokes from right handed to left handed equally, and this will avoid any tendency to leave the bottom of the hoof windswept (see Diag 1).

Tom Stovall, renowned CJF from Texas, refers to this as RHD or Right Handed Disease and says in his colourful way:
“RHD is usually the result of a sharp rasp and fatigue. It's most often manifest on the right hind when an operator gets a little tired, especially at the end of a long day, and most especially when some ill-broke puke is the last horse of the day and makes the hoof a moving target. It's the result of an operator's pushing the rasp down on the lateral edge of the hoof instead of across the hoof and will gut the quarters quicker than Bob can get the news. Occasionally, both hinds may be involved in the presentation, but that presentation presumes a new rasp and a very tired/inept mechanic (from http://www.horseshoes.com/forums/showthread.php?t=6597).

The rasp isn’t the only culprit, as the other tools all play a part in poor hoof preparation.

I stated in a recent article I wrote entitled ‘Creeping Toe Syndrome’ that the majority of horses front hooves at re-shoeing time will have stretched forwards at the toes, which causes the hoof to slow down at the point of its break over and also puts excessive stress on the supporting tendons, and puts excessive wear at the toe of the shoe - all that is the effect of those long toes.

Viewed from the bottom, the ideal hoof capsule should be an even thickness outside the white line all around (Diag 2) and that is also the same shape as the normal coronary band.
Correct preparation of the sole is the first step and it is somewhat of an art to use the sole knife to do this, taking out the excess flakey sole and excess bars to achieve the right concavity and to then identify where the true junction of the hoof wall/sole is. Too often our hands and the sole knife will do either too much or not enough at this point, so it is important to get it just right.

Picking up the nippers we all know that the hoof wall must be level and flat for shoe fit preparation. If the owner has requested that the horse is to go without shoes for a while, we have to make those hands and nippers leave enough height of hoof wall for the horse to walk on; it may not be all that easy to get an even cut 5mm above the sole junction all around, but that is where the horse will be comfortable without shoes, so that is where we have to stop.

To finish off the job, too often the rasp flies into action with far too much enthusiasm, and it is too easy to take off far too much with that rasp and undo all that hard work. Again, hold the rasp between thumb and forefinger only.

There are only three basic shapes of the horse’s front hoof and they apply to most breeds: they are either (1) round, (2) oval or (3) egg shaped, and most factory made front shoes are round in the front half with provision for the heel section to be modified to fit correctly. With oval shaped and egg shaped front foot shapes, you will notice that the coronary band above is usually round, indicating that this is the desired shape of the hoof so you just need to control the flares in the distorted walls. Yes they are flares, and need to be controlled. There is no such thing as a natural flare in the hoof.

The natural shape of the hind hoof has a narrow toe with slightly curved sides back to the heels, and the white line in the bottom of the hoof also confirms this, as does the normal shape of the coronary band of the hinds.

Careful use of the rasp to control this shape is essential to enable the horse to stand straight behind with no outside flare, because that flare will cause the horse to point out cow hocked (see Diag 3) and to also develop back strain.

Sadly some factory produced hind shoes are now being made with left and right profiles and it is my belief that if we follow their trend, it does not help us to prepare the hoof correctly for the horse. The horse’s hoof is the same as it always has been, but opportunistic marketing will always offer us a bandaid to use instead of doing the job properly in the first place.

In conclusion I stress the need to be fully aware of the expectations of the horse owner and the horse’s mobility before starting the job: use good sharp tools and use them lovingly, don’t use them as weapons of mass destruction.