Vet Dr Annie Ashman MA. Vet MB. MRCVS tells us her thoughts on Farriery and Foot Imbalance
How closely does your veterinary surgeon work with your farrier? In my opinion, this relationship should be very close indeed. Part of my responsibility as a vet in the Royal Army Veterinary Corps (many years ago!) was to ensure that the qualifications of the Army farriers were in line with those offered by the Colleges thus ensuring that the Army Farriers could gain the Dip.WCF and higher qualifications which would allow them to practice farriery as a civilian. This gave me a close working relationship with those in the forge at Melton Mowbray and thus a high regard for these highly skilled craftsmen. I taught the trainees the veterinary aspect of their job and in doing so gained a better understanding of foot anatomy and general limb biomechanics.
Now 25 years later, when reviewing not only claims and problem cases but also Vet’s Certificates at purchase I am struck by the number of times I see a vet’s comments that “The toes are too long”,” there is a medial/lateral imbalance” or “the shoeing needs attention”. Today alone half of our claims were for lameness and of them half again were related to foot balance. In numerous cases of coffin joint, navicular syndrome or other foot lameness if there is a veterinary certificate available I will check this out of interest. In about half the cases I see a note on the certificate that there was a foot balance problem. In some cases, there has been an initial exclusion applied which has been lifted six months later with a vets report that the feet were now adequately balanced. So what has gone wrong? What should a balanced foot be like? And what consequences are there for not having a correctly balanced foot?
We are all aware that horses are athletic animals. They are evolved as flight animals and carry all their weight on their central toe. The hoof is the equivalent of the fingernail- the carpus (knee) the equivalent of the wrist and our finger joints are represented by the coffin, pastern, and fetlock. In the hind limb, our heel is the equivalent of the horse’s point of the hock. This anatomy has the advantage of very little muscle or weight at the bottom of the limbs, thus allowing easier and faster movement. For the most efficient movement, there must be least strain on all the joints. The weight is taken by the horn tubules in the hoof and the minute interdigitations of the laminae which give both strength and a large surface area on which to weight bear folded into a relatively small space. On hitting the ground the foot will expand slightly aiding shock absorption along with the lateral cartilages, frog and digital cushion. For maximum strength, the horn tubules must be parallel (try bending a bunch of drinking straws- first held together with an elastic band at both ends, then with a band just at one end). The laminae and horn tubules form along the pedal bone in the foot from the sensitive laminae or “quick” in human parlance. In addition to this, the deep digital flexor tendon inserts onto the pedal bone via the navicular and the force of the tendon pull is effectively anchored by the laminae. (In laminitis cases where the laminae are weakened there is rotation of the pedal bone and flattening of the feet at least, penetration of the sole at worst.)
So what happens if the feet change in shape? Horses’ feet do of course change shape as the horn grows and it is doing so all the time. As with fingernails unless trimmed and filed regularly they can soon get out of shape. Whilst this is largely aesthetic for humans in equines this can cause a myriad of problems. If you are in any doubt that long toes are not uncomfortable for the horse I would suggest that you try and bend your fingernail back. For the horse, it causes leverage on the pedal bone and weakening of the horn tubules. Long toes cause the foot-pastern axis to be tipped back, the heels to slide under the foot and increased force on the tendons and joints. Repetitive strain can lead to damage to the tendons both within the foot and higher up. Increased wear and tear will eventually lead to arthritic conditions.
The ideal equine athlete would have a smooth arc for a stride pattern where opposite limbs pass mid-flight. The foot should land squarely, with a little slip which aids in shock absorption and the break-over point should be at the tip of the pedal bone. The perfect conformation would result in equal force on both sides of the limb and consequently least stress on the joints. Should the foot land unevenly concussive forces are then born by the side of the hoof which lands first. A medial to lateral (side to side) imbalance, in simple terms, will cause a twisting of the structures inside the hoof capsule- No wonder we see coffin joint arthritis, navicular bursitis and damage to the deep digital flexor tendon with the foot! Some years ago when my children were in the Pony Club I was asked to talk about foot balance at Camp. I asked for volunteers with size 5 feet and duly handed out a variety of footwear from wellies to stilettos and trainers. I then asked the children to run a short distance, change shoes and run again. Not surprisingly running in the trainers was easier. Finally, I asked them to mix up the shoes. All found it easier to move when wearing a matched pair! Strangely quite a few of the ponies at camp did not have well-balanced feet – I hope I gave cause for thought.
So how do the horses’ feet get to be out of balance? Well, it certainly is not all your farrier’s fault. You will be aware that your fingernails do not all grow at exactly the same rate. It is tempting not to call the farrier until you think that the horse needs shoeing for financial reasons and then the farrier can only deal with what is in front of them. If you have ever cut your toenails too short you will understand why it is impossible to correct an imbalance in one go! If the toes are cut back and the next set of shoes are left on for 7or 8 weeks then it is back to square one. As a general rule, horses should be regularly shod every 5 weeks which allows for horn growth, but not enough to change the balance of the foot-pastern axis when reshod. Most remedial farriery is carried out at slightly shorter intervals. Farriers often will get asked to do more horses than they are booked for and then time pressures may mean that less attention is paid to detail. Farriery is a skilled job and requires much concentration. My farrier prefers not to do all 3 of my horses at the same time for this reason. Medial to lateral imbalances can sometimes be exacerbated by farriers pulling the foot away from the horse to trim the horn and levelling by eye. I was taught by a farriery examiner that the correct way to check was to hold a forelimb by the knee, let the foot drop and look down at it over the shoulder. My farrier always does this but I suspect a few do not.
You might ask yourself how you would know that your farrier is doing a good job. Sometimes it is just a relief to get a farrier to come at all and if you only ever see one person’s work there is no benchmark. Whilst there is no mandatory requirement for farriers to undertake CPD (Continuing Professional Development) once qualified as for veterinary surgeons, this is likely in the future and CPD is strongly encouraged by the Worshipful Company of Farriers. The keen and interested farriers will already be attending further training of their own accord and might also be partaking in farriery competitions, judged only by approved judges who are listed on the WCF website. If your farrier attends courses from time to time or takes part in shoeing competitions you can be reasonably confident that he or she is one of the better ones. We are proud to announce that our KBIS sponsored rider Izzy Taylor, won the prize for the best shod horse at Badminton, judged by World Champion Farrier Jim Blurton AWCF. Huge congratulations to her farrier and boyfriend Charlie Sands.
Although all farriers have to hold the Diploma of the Worshipful Company of Farriers, there are two further qualifications which farriers can study:, The AWCF (Associate of the Worshipful Company of Farriers) which examines theory of anatomy, physiology and remedial farriery as well as practical remedial shoeing, and the highest award, the FWCF (Fellow) for which a thesis has to be written in addition to practical specialist shoeing. Personally I think that all remedial farriery should be carried out by people with these higher qualifications as it proves that they have done the requisite amount of study and are able to read radiographs for example. However many veterinary practices will use experienced DipWCF farriers for their problem cases.
I am fortunate that my farrier holds the AWCF so I am confident that any foot balance problems will be averted before they start, but every farrier attaining the DipWCF is examined on foot balance for qualification. As horse owners, it is our responsibility to help our farrier keep our horses’ feet in perfect balance by booking them often enough, so helping to avoid future injury. As veterinary surgeons, it is our responsibility to work closely with the farriers to aid in both prevention and recovery from injury. I have personal experience of many horses which would otherwise have been written off that have had successful athletic careers thanks to liaison with a skilled remedial farrier.