In this paper I would like to discuss the effects a shoe could have on the foot.The type of shoe and the position of the shoe on the foot can affect the internal structures of the foot.This can be a positive or negative effect on the foot and/or upper body because as we know the orthopaedic stance of the horse will have an influence on the muscular-skeletal system of the horse.  

Shoes are designed to  

1.protect the foot from undue wear; and

2.give extra grip on difficult terrain.  

 A horses foot was not meant to have shoes fitted as its own natural hoof can do this very well.So if we are going to fit shoes we must understand and consider what effect a shoe will have on the horse as shoes can place unnatural pressure on the hoof and upper body.  

 A shoe should fit as closely to the alignment of the hoof capsule as possible and the shoe should only be made of a material that is as light as possible to perform the job. As a general rule I fit a light concave metal shoe and follow the outline of the hoof capsule.This is to keep the pressure on the hoof tissue as close to natural as possible.  

 Why a concave shoe? A concave shoe places its support directly under the hoof wall as in an unshod foot.Keeping it as light as possible keeps extra weight and stress off the hoof and muscular-skeletal system.  

So when fitting a shoe we must understand that if we change the bearing surface of the foot with a shoe then this will change the way the vascular system and tissue of the foot performs.What do I mean by changing the bearing surface?  

 The feet carry the weight of the horse and they can perform this even with some minor podiatry problems, but if we decide that a shoe is needed to correct some of these podiatry problems and fit a flat wide wedge shoe positioned outside the hoof alignment, then this will place extra pressure on the internal workings of the foot.This extra pressure can alter the vascular flow to the foot and then the tissue of the foot will begin to break down.When this occurs the orthopaedic stance of the horse is compromised and the muscular-skeletal system of the horse is placed under huge amounts of stress.  

 Lets look as some shoe placements and see what, if any extra pressure is placed on the foot.

  Placing a shoe outside of the hoof alignment acts like a lever on the hoof wall and internal tissue (too much leverage will stop growth).The new hoof wall growth will be under pressure and could change its growing patterns.If you combine this with a bar such as, egg, heart or straight bar, again this extra pressure being placed away from the alignment of the hoof capsule will cause tissue and vascular flow changes and this could lead to long term podiatry problems.

Because this type of shoe placement can cause long term problems I suggest only using them for periods of no longer than two months.  

 Shoe placement is very important to repairing podiatry problems in horses.If we take underrun heels as one problem and look at how a shoe placement will help or hinder the treatment of this condition. We have all been told to place the shoe where the foot should be and even bring the heels of the shoe in to support the back of the foot.When this strategy is adopted the shoe will act like a vice on the hoof wall and the shoe supports the foot too much and stops the hoof flexing or rolling out of the way.When weight is placed on it the extra shoe support closer to the frog will only place more pressure in the back of the hoof.When this all occurs the extra loading of the hoof goes on the digital cushion, distal cartilages, distal sesamoid area and vascular system of the foot. Overloading of these areas means that the tissue in the hoof will not be able to cope and will begin to break down and you will never have a successful outcome.When bar shoes are used for prolonged periods then the extra pressure placed on the corium of the sole will change growth patterns due to the changing in the vascular flow and the tissue will break down.To a lesser degree rolling the toe on the shoe will again place pressure in an unnatural way and change the vascular flow in that area and the tissue in that area will change.

Raising the heels on a horse is another thing that if not required will change the complete biomechanics of the hoof and upper body.Raising the heels, if the heels are not lower than natural will overload the back half of the hoof structure and if the toe of the foot is longer as well then we are causing the hoof capsule to move away from correct alignment with the bone structure.We have to also keep in mind that the upper body as well will be changing the muscular-skeletal relationship and placingstress on the suspensory apparatus.  

 I have a very strong belief that we must keep as much unnatural pressure out of the foot as possible as to maintain correct vascular flow so the hoof tissue can cope and be able to constantly repair itself.Treating these podiatry problems is a long term treatment and we must take it slow to give hoof tissue time to repair.Slowly correct the orthopaedic stance of the horse (the way the hoof carries the horses weight) and reduce the amount of stress in the feet as this will return vascular flow to the foot and then tissue can begin to repair itself.I always try to keep a shoe to the alignment of the hoof capsule and slowly start a program of orthopaedically balancing the foot and as the foot begins to repair itself I then find that the shoe placement becomes more of what we would expect and the foot returns to having excellent growth indicating that the repairing of the hoof is consistent.