The discussion was with Andrew Mahon who is the resident farrier at Tattersalls and John Killingbeck who often acts as FEI vet, is renowned as a lameness expert and is an examiner of farriers.

John Killingbeck was first asked about the physiology of the horse’s leg that we should be aware of before putting studs in.

‘It is worth remembering what we do when choosing studs and what the horse’s natural function of the foot is. The foot is designed to absorb the impact of landing and it does it by absorbing concussion. Part of that concussion is done through the foot sliding and that absorbs the stresses and strains of landing. We know from projects that the impact stresses on barefoot feet are less than that of a shod foot. We are effectively changing the mechanical effect of the foot. The shoe to a certain point compromises the function  of the foot in absorbing impact. Does this contribute to modern injuries that I now see as a vet – it does.’

Andrew Mahon: ‘When I first started to shoe horses, studs were not used to the extent that they are now, basically we know why we stud, it’s to grip. You are looking for that edge over the competition so you can get a little bit quicker, jump a little higher and a little bit faster. Studs are becoming more important in people’s minds when they are looking at the ground conditions and they are doing more. In some cases I have seen up to five studs in one shoe.’

‘As a farrier I am asked to put the stud holes into the shoe but I have no idea what size studs people are using, but I feel that people are using bigger studs if they feel that the ground conditions are slippery. Sometimes as a farrier I am asked where studs should be, sometimes I am told. I have been asked to put four in the front and five in the back before. Three on the outside and two on the inside’

Eric Smiley then asked John Killingbeck where the stresses and strains appear from using that amount of studs.

‘You reduce the load bearing surface because you concentrate the pressure into the toe and the point of contact into the stud. Shoes wont carry any pressure until the stud has gone into the ground. If you look at human athletes, research has shown that as the grip has increased with competition shoes the athletes have been getting more and more knee injuries. The question I have is if one factors in the complexity of proximal suspensory injuries that you see now and I wonder if it’s not a vertical effect that we see on the road and I wonder if by decelerating the slip on the foot that some of the horse’s momentum has to go somewhere and it is being absorbed by the soft tissue structures above the foot such as the tendon and suspensory. The tendons take an increasing load with speed and stride length and the suspensory ligament is under permanent strain even on straight lines. If the foot stops the upper structures of the leg keep going. I think this is something we should be aware of. The horses have learnt how to slip, the foot has slipped for 55 million years so there is that inherent properception to cope.’

Eric Smiley asked about surfaces and if they have changed biomechanics.

John Killingbeck: ‘I think the increased use of all weather surfaces is a factor. People who walk about on all weather surfaces all day tell me that they feel more soreness in their legs at the end of the day. Horses will get sore joints and suspensories and a lot of those horses will jump better on grass than they will on an all weather surface because of the slip.’

Andrew Mahon: ‘ I have found that since arenas have become more popular and more widespread that people don’t realise they do a lot of work in the arena. It’s fantastic, it’s all weather, they put a harrow on it but there are more injuries on sand all weathers than there is on grass. If you are going to a big competition and you have done 90% of your work on an arena then you horse has to acclimatise to how it will move, so they stud to compensate and the horse is unsure of itself. You have to train the horse on turf if you are going to a big show so it knows how to slip a little bit and get its confidence. Nothing is worse than a horse which does not know how to slip a little bit. Even with big studs it will slide that little bit.’

JK: ‘ How many riders have lost a shoe on the cross country course probably with studs in it and not felt handicapped?’

AM: ‘The type of work has changed over the years. Road work was a big factor which is not being done as much now because of traffic. Also a lot of horses are not being hunted where they know how to slip. Out hunting they know how to correct themselves. That type of work was invaluable and I don’t see a lot of people doing that. They are doing arena work for dressage and showjumping and they are not doing the work over different ground. It is going out in open fields, jumping ditches and getting the horse to learn to slide in different conditions. The type of weather we have at the moment is wet. Putting studs in, is that going to make a great difference if you are coming into an open ditch? probably not. That small thing of letting the horse get its own balance, letting it slide a little bit. It has evolved for millions of years, it knows how to slip, it is designed to slip. The sole is concave to grip into the ground. The frog is a wedge which as it slides, it acts as a brake. The bars of the hoof, everything works together. Too much is being taken away from that. I also say to farriers, those parts are important, don’t interfere too much with them. Aid them. It is a big factor for farriers overdoing it. Bring it back to basics. A lot of problems with studs are from people overthinking it. If you are overthinking it then you are putting too many studs in. Bring it back. Go back to basics and see if you can teach your horse the basics again.’

Eric Smiley: ‘ Some people say farriers will do what they want anyway?’

AM: ‘ The way I think about it, if you can get a good farrier and a good vet to work together then communication is the key. Farrier will ask the history of the horse. Is the horse losing shoes? Yes, why? The simple thing of why? Is your horse sound? No, when it gets to the 2nd trot up we are all having sleepless nights. Why? That is where good communication is vital. You know your horse, share that knowledge and there should be no sleepless nights. We are all here for a sound horse.’

ES: ‘ John, can I ask you about the natural balance process?’

JK: ‘ Natural balance was derived from research done in the United States and found that wild horses wore their foot in certain ways which gave an indication about which shoe would be most appropriate. I think a lot of these things are a fashion and there are some people who can fit any type of shoe to any kind of foot with the right preparation. We have to be careful not to advocate a certain type of shoe because you have to have a foot shape in mind to fit that shoe. In my experience natural balance shoes are ok in the short term but in the long term I have seen more problems than I have seen benefits.’

ES: ‘Are there changes to the type of feet you see nowadays?’

JK: ‘ The biggest problem across the board comes from TB feet, because TBs have not been selected for the quality of their feet. They often have weaker soles so they often do not cope with anything other than a very manicured surface like a racecourse. If you were to trot up 50 horses here on a nice level surface and then take their shoes off and trot them up again, the vast majority would move with more freedom than if they were shod. So the mechanical effect of the shoe comes at a price. It’s a necessary price. If people are aware of it, especially the long period of time horses are shod, horses need a period of time with no shoes on to recover. You compromise the blood flow which you cannot see with shoes.’

ES: ‘When you say recover, how long does it take without shoes?’

JK: ‘ It’s a very individual scenario depending on the quality of the foot and the quality of the farrier but if it has progressed to the stage of lameness where you have ruled out most things inside the foot and you think it’s mechanical stresses and strains. If you think about fingernails and how long they take to recover from bruises, you can see that. You are not galloping on your fingernails, so if you magnify that up to the horse’s scenario, you need quite a long time for the structure to recover. The structure which is painful are the laminae. So what you are talking about is mild Laminitis. It does not create a hopping lame horse but you lose that bit of freedom and movement and everything slips back to compensate. Backs become slightly sore, suspensories become slightly sore.’

ES: ‘ Andrew, do you see foot issues with people using studs on hard ground?’

AM: ‘ I do, I see stress problems. If you put studs into a horse and you ride on hard ground, you have these two studs adding to pressure. The hoof is softer and twisting. If the shoe is put on well and strong then you are going to have a problem going up the leg. The joints move forwards and back, they have very little rotation movement at all so then if the shoe stays on it could very well be twisted off in hard ground. So, you have no shoe and no studs and no grip. If you watch  show jumping against the clock where they have to turn sharp, the head is often turned but the horse is taking a long arc, think to yourself is the horse sore? he has two studs in, the ground is hardish and it’s not twisting, the legs are not able to pivot and locked into the ground. The legs are not designed to be locked in. The hoof quality can be poor with this pressure and just break off. Trying to get a shoe onto a crumbly foot is difficult. At Tattersalls I have spent up to 2am trying to rebuild a hoof. I cannot put a shoe onto nothing. I have to pull a trick out of a bag with cement. This can be down to studs.’

ES: ‘ Should we ban studs?’

JK: ‘ It’s a very complex subject and we have to recognise that rider confidence which translates to the horse. We have to hope that people appreciate the effect of studs and are then more careful with how they use them. It gives me horrors watching people hacking down the road with their studs in from the stables. It does not take very long to have an effect on the internal structures of the foot. They are a necessity but they have to be used carefully. Stud design is important. They should go into the ground easily and come out of the ground easily. You do not want to increase the grip and traction anymore than you need to. Add into this complexity horses who have learnt to slip and have had studs added and the cautious horse who likes grip. Riders need to understand the physical effect of studs not only on feet but also the upper limbs. Studs should not be abused.’

AM: ‘ We need to educate people to think about the number of studs, the height of studs, the ground conditions in which you are jumping. Is it slop? Then studs are not going to make a very big difference. If you put too big a stud in are you going to hurt the horse? Are you going to alter the stride? A lot of fences are done as a permanent fixture with hardcore in front to keep it safe, if you have studs in and the horse is coming from clay, you have to think about this. You can train your horse better without studs. If you lose shoes on a regular basis, then you don’t have studs!’

Eric Smiley summarised that riders needed to look at training horses and improving the rider’s education about studs and training the horse without studs.

Lucinda Green (quoted with permission):

“The high resolution slow mo video of the ‘2 studs, 1 stud no studs turning’ that Russell Guire (of Centaur Biomechanics) and I did 2 years ago showed:
no stud: slight slippage forward of foot and turn
1 stud: foot spun straight round
2 studs: foot turned in a series of judders.

I talked to Andrew Mahon the Farrier at the Forum – he was clear that what is best for the physiology of the horse is no studs / if it’s slippery then road studs – if it’s really bad the next size up (it looked in his picture as if they were under 1/2″) and always only on outside //// u take your horses natural way away if u stud but sometimes u have to help – but we just need to know that at the same time as we r trying to help we r also hurting them – and so I guess don’t just put them in willy nilly / use a judgment each time.
Interesting at 2 star event in China in Dec – studs worn all over the place and I’ve never seen so many falls on flat / both on corners and after jumps / v difficult ground (a few inches of sand and slippy clay beneath) It’s good that the downsides have been flagged up – and then personal judgment and balancing the odds follows.”

This video clearly shows in slow motion how hooves impact the ground. At 29 seconds there is a perfect example of hind hoof twisting on the ground.