Webinar – Does a 4-6 Week Shoeing Interval Promote Optimal Foot Balance? Dr Kirsty Lesniak

“Does Saving a Little Cost a Lot?” — Hoof Care Intervals and Equine Soundness

In this insightful and thought-provoking session, senior lecturer Dr Kirsty Lesniak from Hartpury University explores the delicate balance between cost-saving and hoof health in the management of shoeing intervals. Drawing on her academic research and hands-on dissection experience, Kirsty delves into how hoof balance and limb conformation influence the biomechanics and long-term soundness of the horse.

This webinar takes a deep dive into what really happens to the foot and the entire limb between shoeing intervals. Are four to six weeks enough? What’s the hidden cost of pushing to seven or eight weeks? And just how far-reaching are the effects of a slightly altered hoof angle?

With easy-to-understand anatomical explanations and real data from a published study, the session unpacks how subtle changes at the hoof level may ripple through the entire musculoskeletal system. While the webinar does raise questions about the financial pressures facing owners today, it also invites us to consider the broader implications on performance, welfare, and longevity.

Whether you’re an owner, farrier, barefoot practitioner, or simply interested in your horse’s hooves, this talk offers plenty of food for thought – without giving away all the answers.

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Transcription
Here is a transcription of the webinar. (Please note this is an automated transcription, so we apologise for any errors.)

Hi, my name’s Kirsty Lesniak and I am one of the senior lecturers at Hartbury University. And I’ve been asked by the Animal Web team to come and talk to you today about some work that I’ve done looking at hoof care intervals, particularly looking at shoeing intervals and the implications that this might have if we leave these intervals too long and therefore.

ensuring that we are looking after optimal health for the horse’s foot and the distal limb as well as the more holistic approach of looking after the whole horse in general. So this was based on a study that I did called does a four to six week shoeing interval promote optimal foot balance? However, I also kind of present this topic under a slightly different name and that does saving a little cost a lot, the potential expense of an extended shoeing interval.

It’s a little bit of a mouthful but I think it kind of conveys the underlying meaning to it which is we can extend the shoeing interval and save ourselves financially but does this have a potential expense to the horse and or to us when we’re thinking about the health of the distal limb and the health of the horse in general? So I’m going to elaborate on this in a little bit but first of all I thought I better introduce

myself a bit more and where I’m coming from and my approach to this. So I, as I said, I’m a senior lecturer at Hartbury University. As part of that role, I do both teaching and research. My teaching areas are anatomy and physiology. And through that and through my research on anatomical symmetry, I’ve kind of fallen in love with the horse’s feet. Initially, I was trying to find out why and whether they were actually involved in sort of

compensating and supporting any anatomical symmetries that we saw in the bone structure. But then I fell in love with them and their intricacies and their anomalies and realized that we know very little really when it comes to the foot. And so a lot of my research has then been recently around normal hoof conformation, the different demographics and factors that can influence hoof conformation. And that’s where I’m coming from.

So I’m not a hoof care practitioner, I’m not a farrier. I’m an academic and a researcher with a vested interest in this area. And I do an awful lot of dissections of the distal limb and the hooves with sort of bearing in mind the things that I research and seeing the impact of these on the underlying structures. So I’m gonna start off then, if I’m not a farrier, what is the role of the farrier? Because they’re the really important people in this sort of equation.

And whilst I use the term farrier a lot, I’m going to also encompass sort of hoof care practitioners into that. So thinking about barefoot practitioners as well. So as much as I will refer to farriers, I will sort of mean everybody and hoof care practitioners integrated within that. It’s just a little bit more of a mouthful. So I’ll stick to farriers for the minute. So as you’re aware, more, you know,

The saying no foot no horse is one that we’ve lived by for a long time. And we know that hoof conformation, which refers to sort of the morphology, the shape of the static foot, hoof conformation plays an important part in our horse’s soundness and distal limb health. We can consider the term hoof balance and hoof balance is kind of used as a term to look at the geometric portions of the foot.

but it’s not just about the static foot. When we talk about hoof balance, we’re talking about how that foot interacts with the rest of the limb, and then how that limb and foot interact with the ground, both statically, but also importantly, whilst the limb is moving. So balance has to be something that isn’t just seen in the static limb, it’s something that’s seen in the moving horse. And we can consider balance both in what we call a dorso palma perspective, which is sort of the front of the foot.

the back of the foot so if we’re looking at it from the side that would be sort of our lateral view and we can also look at it from the medial and lateral perspective so looking at the foot from the front and seeing whether that foot is balanced from the front and in terms of the role of the hoof care practitioner or the farriers they have a fundamental role in ensuring

and promoting the balance of the feet to facilitate that optimal movement to help prevent injury and as part of it in our modern day horse to really try and improve performance. And through all of that, we should be able to extend that horse’s career longevity. We should be able to ensure that their performance is as optimal as it can be because we’ve balanced the foot to enable the horse to move more comfortably and to move in a way that really

improves its way of going and looks after the remain the rest of the anatomical structures that are linked with that movement.

Interestingly though, whilst we rely on the farrier and the barefoot practitioner so much in practice, still very little is really understood about what constitutes a normal foot. We know far more about what constitutes an abnormal foot, we know far more about the impact of placing things like heel and toe wedges and lateral extensions on the foot, but we haven’t really got

to the bottom of what a normal foot should look like and how that might vary depending on the individual. So how a normal foot for a ferebred would look compared to a normal foot for a Welsh Cobb, compared to a normal foot for a Warmblood. How a normal foot for a dressage horse might look and whether that differs if the dressage horse is above 16 hands or below 16 hands or above 500 kilos or below 500 kilos and the factors that influence those.

So we still haven’t actually defined a lot of the optimums for horses within our care. And that’s kind of what I’m trying to go some way to sort of do is to fill that gap. Now, in terms of hoof care intervention, whether that be through farriery or barefoot practitioner trimming, we know that there are various intervention lengths, intervals.

we describe them as, that are used in practice. So anecdotally, interval lengths commonly vary between four and up to eight weeks, especially within leisure horses. Some might be even longer than eight weeks. However, we also know that within hoof-related research, those intervals vary as well. And some of the research either reports them as four to six weeks or six to eight weeks.

And some of the research that we know about and some of the research that’s talked about the impact of interval length has looked at that longer length, looked at sort of the six to eight weeks and not really focused very much on the four to six weeks. So the majority of studies that have evaluated changes in the distal limb structure because of the interval length have looked at those changes associated with eight weeks of length. So.

In terms of what the foot is doing, before I start to talk about the study, I just kind of want to put into context what the foot is doing. So this is a little sort of amalgamation of a couple of images to kind of illustrate to you this what we describe as load equilibrium. So what you can see here, if I get my little laser pointer up, is you’ve got each of the three bones. So there’s P1,

which is up here, so P1 is the first phalanx, P2 is the second and P3 is the third, that’s the coffin bone. And in between each of these bones is a joint. We’ve got the distal interphalangeal joint here, we’ve got the proximal interphalangeal joint here, and way up here we’d have the metacarpal phalangeal joint or the fetlock joint. And these little blue circles crudely relate or reflect the center of rotation of those joints. Now,

there are different forces acting on these joints depending on the load. Now there is the body weight, so as body weight is loaded, that’s going to create a clockwise movement here. So clockwise force at the coffin joint or the distal interphalangeal joint is the limb is loaded. But as that is then pulling, because we’ve got the deep digital flexor tendon, which is this structure you can see at the back here, faded structure, this deep digital flexor tendon,

then inserts onto P3. As P3 is then loaded and the distal interphalangeal joint is encouraged to rotate in a clockwise direction, there is a pull then on the deep digital flexor tendon. So these are basic biomechanical concepts that we load. This joint, we get a clockwise force at the distal interphalangeal joint. And at the same time, we’re getting a pull.

the deep digital flexor tendon which creates this counterclockwise force. Now between the two of those, there should be an equilibrium that’s created. And that’s specifically helped by the structure that aligns the front of the foot here and around the dorsal wall. And that’s our beautiful laminar junction, which basically is like awesome biological Velcro.

which valcros the horse into its hoof capsules and suspends it off the floor. So it doesn’t bear weight on the sole, on the underside of its bones like we do. So when we’re standing, the base of our heels, the bones in our foot have got a soft squidgy pad of flesh underneath them. And we are loading those bones with that load being cushioned by that soft squidgy pad underneath our foot. The horse isn’t like that. If we stand the horse on hard ground, then actually,

100 % of the load should be born around the hoof wall and none through the sole. It’s only really when we take the horse on soft ground, such as out in the fields or in the arenas, and those soft surfaces, as the foot sort of cuts into the ground, those soft surfaces come up and meet the sole, that some of that load is then taken up by the sole. But even then, that’s still only about 25 to 30 % of the load and the majority is still being born by the hoof wall. So the hoof wall plays a really important role.

and the wall then being attached to P3 by this beautiful laminar junction. So that means that P3 should be held in place. Okay, so P3 is held in place. And as we get this rotational force here, that creates strain energy through here because we’re not getting movement of P3 or we shouldn’t be getting movement of P3. It should stay where it is, glued into place, farrowed into place here. And so this deep digital flexor tendon is put under strain.

And that strain, that strain energy is what helps the horse move so that when it lifts its foot up, break over, the elastic strain energy that’s been stored in that tendon then helps to lift the foot off the ground. It kind of recoils that tendon that’s been stretched out, recoils it, and it helps lift that foot off the ground. But there’s a very clear balance between these structures. And there’s what I quite often refer to as this

anatomical interrelationship. So here we’ve got the coffin bone, our P3 bone. We’ve got the beautiful biological Velcro, which is the laminar junction and the hoof wall here. And underneath here, we’ve got the deep digital flexor tendon that’s this tiny sort of thin strip that’s running sort of up through here. So tiny thin strip that’s running up through here. And then we’ve got the digital cushion here.

and the bulba cushion at the back here. So our deep digital flexor tendon is running up through here with the digital cushion and the bulba cushion underneath it to provide it with some padding. Now that’s running very closely to these navicular structures. We’ve got the navicular bone here and the ligaments, suspensory ligaments that support it alongside the navicular bursa. But if we then look further up the foot, so here we’ve got our deep digital flexor tendon. We’ve got

the second phalanx and third phalanx here and the deep digital flexor tendon runs all the way up, all the way up the limb until it gets to the deep digital flexor muscle above the level of the carpal joint, above the level of the knee. So any alterations that we make down here into the balance and the conformation of this foot that then alter the tension in this deep digital flexor tendon will then alter the tension all the way up, all the way up the limb.

and actually through the muscle and to the origin point of the muscle, up on the elbow and the level of the humerus, right at the top. So the impacts we can make at the bottom are far wider reaching than just the bottom of the foot. The changes we make at the bottom affect all the way up the limb. And we quite often think of the fore and the hind limbs being two points of a triangle.

with the back being that third point. So if you affect the positioning of one or the functioning of one, you’re going to affect the others. So it has a more holistic impact. If we think of a horse with back pain, sometimes that back pain can be because of what’s going on in the feet and the way it’s had to hold itself, the posture it’s being forced into because of the shape of its feet. And therefore we’re getting back pain, potentially even hindquarter pain because of the positioning of the hind limbs as a consequence.

So we have to think slightly wider than just the impacts of the foot. And I would really love it for one day there to be some brilliant scientists that comes up and defines my undefined golden ratio. Because there is a sort what I described to my students as a golden ratio between the amount of load that the bone structure of the limb should take up and the amount of load that the soft tissue structure at the back of the limb should take up. And we don’t know what that ratio is. We don’t know

exactly what percentage of load the bone column should take up and what percentage the soft tissue should take up, but we know that the bone column should take up more because it’s evolved to do that. The soft tissue support, they are incredibly important for ensuring that we don’t get collapse of this structure here because whilst the majority of the limb is a bony column, particularly when we talk about the forelimb, we do have this angled joint here

which laws of physics say this shouldn’t really be able to stand upright. And therefore the soft tissue, our suspensory ligament, the 2D digital flexor tendons amongst others are important for holding this structure up and allowing it to move effectively to drop down during locomotion and therefore create tension in the flexor tendons to create this elastic strain energy that reduces the cost of locomotion. Now,

If we’ve got ideal loading and an ideal ratio between these two, then that should ensure that the articulating surfaces of the joints are appropriately loaded. They meet where they should do, they flex to the maximum amount they should do and extend to the maximum amount they should do. If you look at bones, the ends of bones on dissected specimens, you’ll see that there are

flattened areas of articulating surface on those bones that you can tell where the end point of articulation is, the end point of movement is. And anything past that would be considered inappropriate. So we know that if we’ve got ideal loading, then actually those articulating surfaces should be loaded appropriately, not just in sort of stance, but in movement too. But actually in stance and through the loading phases of movement are really important because actually that impacts the point of contact

the maximal point of contact that those two articulating surfaces are going to be under. It also means that that bony column is taking up most of the load. And if you look at the microstructure of bone, it really is columnar. So it’s column. And we’ve mimicked that through a lot of our architecture. If you look at a lot of buildings, we base them on column structure because it gives strength. And therefore, the column structure of bone

actually enables that limb to support significant loads, particularly when we think of this modified cannon bone that’s basically a modified third digit, so it’s much stronger and tougher than a lot of other bones. So the suspensory and check apparatus are soft tissue structures at the back of the limb are loaded, but they’re not loaded excessively, they’re loaded at a level that is proportional and an appropriate level. So we’ve got then this balance, equilibrium balance between

the load that the soft tissues and the hard tissues are taking up. But that load can be moved forwards or backwards depending on not just the conformation of the limb, because of course that plays a role too, but also appropriately balanced feet. So conformation and foot balance coming together have an important role in managing this. Now with our undefined golden ratio,

I appreciate this model largely relates to the static horse and we know that limb angulation changes as the horse loads and unloads during locomotion, particularly as speeds increase. But I’m going to base this alignment on sort of the optimum angulation to permit the joints to have, you know, the best range of movement. And so I’ve kind of done my little diagrams to kind of illustrate this. And if the loading becomes too far forward,

As we would see in a horse with upright limbs, so something that’s perhaps quite upright at the pasten, perhaps also then upright at the shoulder as well. In these situations, we’d see that the bony column then takes on too much of the load or takes on more of the load and the tendons and the ligaments and the suspensory apparatus would take on less. We could almost describe that as being underloaded. So the bone would take on too much and the soft tissue would take on too less.

So those soft tissues are potentially also receiving inadequate loads to sufficiently adapt to athletic work. So when they’re then asked to really load through athletic work, and we then ask this Fetlock to drop down through gallop and jumping, they then potentially are being asked to stretch more than they have potentially been able to adapt appropriately to, or have been biologically.

evolved to be able to do and that’s why sometimes those horses can be at risk but one thing they are at risk of is they’re at risk of cartilage and bone damage because of the amount of loading that’s going down through the cartilage through the hard tissue structures through our bony structures and the repeated concussive loads that here so long-term consequences of these upright limbs we know we’ve seen

in practice and in research can be that there is disease of the articular cartilage, particularly at the joint margins but also extending through the joint. So I’m going to click now and there’ll be an image from a dissection I did and you can see on this the articular cartilage damage. It was a particularly damaged cartilage but you can see this. This should be beautiful pearlescent white with no markings all over it but you can see the lines that have come through here.

through scratches and scrapes through overloading and we’ve got sort of bone cysts are happening there too. So this is a very poorly, this is kind of the real sort of end of the scale type damage, but you can see the cartilage, you know, the rest of the cartilage can be quite high within these limbs. The other way around though is that we can actually shift the load backwards.

So if we had something that had long sloping pastons and a very long sloping shoulder, and these are horses that are generally quite soft and comfortable to ride, they give you a real bouncy feel rather than sort of a sort staccato feel as the upright horse does. And in those cases, the bony column isn’t taking on enough of the load and our soft tissue structures, so our suspensory stay and check apparatus, are then taking on more than they should be doing.

and they are at greater risk. So the tensile loads, the pulling loads on those structures invariably results in soft tissue damage, more readily often than the articular damage. in dissections, I quite often see tenderness damage. These are examples of sun. These are quite minor really in relation. So you can see where there’s been some damage here. This is a healthy portion of tendon and this is damaged portion of tendon.

But here we can then see the blood vessel progression through here where we’ve got damage to structures. So you can therefore see the damage that these loading changes have. And that’s not something that we haven’t recognized before there in terms of the association with the foot and the potential for these. So there was a study that was done by Mollman et al in 2006 and they investigated the effects.

of the change in hoof conformation across an eight week shoeing interval and the impact that those changes had on distal limb structures and the working of the distal limbs, such as the biomechanics, the moments, the leverage around those two lower joints in the distal interphalangeal joint and the proximal interphalangeal joint. And Mollman and his team identified that over an eight week intervention interval, hoof angle significantly decreased.

So the toe angle here significantly decreased. It became more acute by somewhere between 2.3 to 3.3 degrees, which doesn’t sound massive, but actually it is. If you wore shoes, high heels that were angled sort of two degrees difference, you definitely know about it. Now, the ground reaction forces didn’t change. The amplitude of the ground reaction forces didn’t change. But what they did notice was that the center of pressure

which is kind of the focal point of the pressure, moved back by just under six millimetres. So across an eight week interval, this moved back by about 5.8 millimetres. So moved in a palmer direction towards the heels, which meant there was increased loading on the heels. Now, those authors concluded that hoof angle decreased significantly, so that became more acute and broken back. It went from, at the start of the study, was about a 55 degree angle, went to just below a 52 degree angle.

And they said that the foot compensated for this change in angle in that it broke back at the hoof-pastin axis. So instead of having a beautiful line, straight line that came through the center of rotation on all those joints and aligned gorgeously our hoof-pastin axis, actually that hoof-pastin axis broke back at the level of the distal interphalangeal joints because there’s very little movement at the proximal interphalangeal joint, this minimal movement.

whereas there’s more movement of the distal interphalangeal joints. So if it’s going to break back anywhere, that’s where it will do. And that then increased the leverage then that that distal interphalangeal joint was then causing on the soft tissue structures at the back of the limb. So that comes to the question of who or what determines that hoof care intervention interval. We know that the…

having the farrier or the barefoot practitioner out and maintaining that equilibrium is important, but who regulates that? And the who is generally person-based, whereas the what is generally driver-based. And we can say the hoof can be our hoof care practitioner, can be the horse, it can be the client. So if we think about the hoof care practitioner, they determine what the intervention should be based on their knowledge and their experience, what they’ve seen in practice.

what they do, what they know that horse needs. And that comes down to the horse as well then. So the horse will be the driver because actually each horse will have its own individual requirements. And that might be that you’ve got a horse that needs more remedial work so the interventions are shorter. It might be that you’ve got a horse that wears down its feet quite well. actually it’s, or it doesn’t grow very fast so you can potentially have a longer interval. But…

In practice, the majority of the decisions often fall with the client. That’s because of their investment in the horse. From this perspective, is both emotional and financial. Those two things can actually be quite conflicting. The emotional side wants to do the best for the horse. The financial side needs to be aware that actually that owner, that client, they are aware that they have other…

factors that they need to pay for that month, things they need to expend out on, and particularly within current economic climates, pennies can be quite tight. So as much as the drivers should be the hoof care practitioners and should be the horse, a lot of the time the drivers are the client and therefore they’re influencing whether their horse goes four weeks, six weeks, or eight weeks, and sometimes even more.

So I wanted to see what the impact of that was further. We knew through Mollman’s study that an eight week interval has an impact. But if we’re saying, you if you speak to most practitioners, they’ll say that four to six week is actually the more ideal. What does a four to six week interval do? How does it promote that appropriate balance? So we did a study that was published back in 2007 now, titled Does a Four to Six Week

shoeing interval promote optimal foot balance in the working equine. And I just wanted to kind of talk you through this and what we found as part of this. And one of the reasons I wanted to do this was because actually we know that there is a financial impact at the moment and that is influencing everything that we do. And so when I sort of published some work that spun off of that particular paper a few years after it,

I wrote an article for a lay journal, a lay press. Within it, I kind of calculated out the values that it would save or cost per annum. And I thought, actually, I’m going to update those values. So recently, I did a bit of a shout out via Facebook and wanted to find out what people are paying roughly for shoes. In honesty, I lost my horse a number of years ago. So it’s been a while since I’ve had to

for shoes myself. And I can honestly say that I was quite shocked because actually the of the of shoes in the UK was averaging between 80 and 100 pounds. I was paying 100 to 120 pound every four to five weeks, 10 to 12 years ago. So the cost of Fariri has not gone up. We are not paying any more now than we were paying 10 to 12 years ago.

but the cost to our failures has significantly gone up. And so that was a real shock for me. But I did put together this little table that sort of shows that I suppose the average costs and the financial outlay and how much it can save. So if we look at a four week interval, you know, that’s 13 interventions per year. If we’re looking at 80 pounds per set, this is our lower end, a hundred pounds per set, our upper end. So your average costs would be here.

Now you can see that as we go five, six, seven, eight weeks, then our average, or sorry, our interventions per year sort of go down and our average cost per set per year goes down as well. So this is per set per year. So we’ve got a sort of quite a significant saving that’s going on through the year. So if we were to work to a six week intervention interval,

Okay, so even if we consider the more optimal intervention of our four to six weeks and an average cost working at a six week rather than a four week interval, that’s about four fewer interventions per year and an annual saving of about £390 per year. If we push that duration out to seven or eight weeks from our four week, we can reduce this by a further two interventions and an annual saving of about £500 per year.

If we go right up to the end of this scale, then we can halve our initial cost that we would be paying out at a four week interval. So we can see that this is a financially attractive sort of method to clients, to horse owners who are trying to save money. That actually does their horse really need to go five weeks? Can they push it to seven weeks? Well, actually it’s looking okay. Could we take it to eight weeks next time?

So it’s not as financially attractive for the farriers, obviously, in terms of their livelihood, more importantly, in terms of managing the feet and the soundness of the horse, we have to question whether this is the best method and what implications this might have. Financially, we can see that it’s attractive, but is it financially attractive in the long term if it’s causing injury? So our study aimed to look at the changes in lengths and angles, so linear and angular changes in the hoof between

the pre post farrier interventions within a four to six week shewing interval. So in essence, what we did was we took images of horses that were in a four to six week shewing interval, had been in a four to six week shewing interval for a minimum of six months. And we looked at those feet before and after a routine shewing intervention to see the difference between the two.

and therefore how the foot had potentially changed across that intervention interval. So we wanted to try and determine from this whether a four to six weeks would be optimal. And so what we did was we looked at 26 horses. As I said, all of them were on a four to six week faring interval. All of them were shod. They were of mixed breed, mixed sex, mixed age and height. So we literally used a whole mixed bundle

from sort of native ponies right up through to your warm bloods and your ex-competition thoroughbreds, et cetera. The most important thing here was they were all on a comparable workload and they were all on comparable management and they had the same farriery team. So whilst it wasn’t the same farrier, they worked within the same farriery teams. There was a lead farrier who oversaw a small team of farriers and they all shod to that protocol. So we minimized as many variables as we could.

And it was those horses, same farrier, I should add. The method then was digital image capture. As I said, one week pre-farrier intervention and one week post-farrier intervention. And then we took, using Dartfish software, we took linear and angular measurements that you can see sort of mocked up here on these images to look at between those two interventions. Now, what was really important was that particularly for, we didn’t go any more than one week

pre the intervention because the foot would have changed quite significantly at that point. So no more than one week before and no less than one week after. So we went to as close to one week within a few days after as possible. part of that is because it takes about four days for a horse to become settled into its new shoes, into its new trim. So that’s something to bear in mind when you’re competing.

is think about where you are having or the timeline in which you’re having your horse shot because actually you want to make sure that you give it enough time to become comfortable in its new feet before you then compete it.

In terms of our results, and this is where I kind of, when I present this in person, where I see some very baffled looking faces when I then present the results, because some of these are not what you then expect to find. Bearing in mind, the farrier at this point has taken a length of foot off of the bottom of the shoe. So if the farrier has then taken the length off of the bottom of the shoe,

Why do we see some of these changes? So if we look from the lateral aspect, some of these changes are as we’d expect. So in terms of the lateral aspect, we see that the dorsal hoof wall angle increases, so it becomes more upright. The heel angle follows that, it becomes more upright. The weight bearing length, so the green line at the bottom, decreases. That’s not surprising really. We’ve taken some length off, but the coronet band length decreased. So how do we decrease the coronet band length when we haven’t trimmed the coronet band?

The palmar coronary band height increases, so the height at the back here increases the red line. How are we getting an increase in height when we’ve then taken stuff off the bottom of the foot? Similarly, if we look from the dorsal view, so from front on, we were seeing the coronet bandwidth again decrease. How did that happen? The weight bearing length decreased, which is expected, but the medial and the lateral, so the left and right hoof wall length, both increased.

How was that happening if we’d taken length off the bottom? And then we looked at what was called Hoof Angle Displacement. So this is the displacement from the sort of ideal Hoof Past and Axis. And we saw the Hoof Angle Displacement. So displacement from the ideal Hoof Past and Axis had decreased. So the Hoof was actually becoming more appropriately aligned, which was a positive. But we were trying to then work out why we were seeing these factors. So…

Other sort of medial lateral alterations included changes or differences in the angle and proportions of the angles. So our pre measurements of the walls, we saw that the lateral wall was four percent longer than the medial, but post that different, that different, that increased. So after shewing, there was a bigger discrepancy between the left and the right, sorry, the median and the lateral walls. Pre and post

terms of the wall angle, we saw that the wall angle, the medial wall angle, was seven percent greater than the lateral wall pre and ten percent greater afterwards. So again we were getting these bigger asymmetries and bigger discrepancies coming through, which was a little bit of a concern at that point, I have to admit, but I’ll explain it all in a minute. And what we did see that was that across this time period as well was actually

at the pre-intervention, so before the horse was then trimmed and rebalanced, actually the centre of pressure was more palmarly placed, so was placed further back and through the trim that was then shifted forward back into what was considered a more correct positioning. So as I said, normally I get very confused faces and this is where I try and explain the why we saw what we saw. So

In terms of what this tells us, this tells us that trimming through farrieri interventions increases the dorsal hoof wall angle, increases the heel angle and the heel height, reduces the weight bearing and the coronary band lengths and reduces the dorsal hoof wall length. So how does it do this? Because if you imagine this little sort of schematic outline as being our pre-foot and then we apply the post-foot over the top, you can see that the foot becomes

taller and narrower and there are slight changes in the angulation that are seen. So where is that coming from? And that’s more easily understood if we actually look at it from a lateral view. So this is our pre-outline. So this is what we saw initially. And actually this horse then has a broken back hoof-pastorn axis, just as Mollman’s studies suggested it would do at the end of the farrier interval. There’s been eight weeks and ours being six weeks, but there was a broken back hoof-pastorn axis.

Once the farrier had then trimmed and taken a length off the bottom, we got a shorter foot. But of course, the foot then doesn’t sit suspended in the air like this. It has to sit on the floor. So if we pop the foot to the floor, actually the leg has then got to change position to then meet it. So we can change the position of the limb and that then changes the position of our hoof-pastorn axis. So to kind of make this clearer,

and to split the two apart. We’ve got our pre on the left and our post on the right. We’ve in effect rotated the hoof capsule. So we’ve taken a bit off the bottom and the rest of the hoof capsule has to rotate. The limb then has to move into a slightly different position to then sit over that new trimmed foot. So we then get a more correct hoof pasten axis.

Now, what you’ve then got to think about is across that four to six week interval, we start off here and then progresses to this broken back. So it’s tipping back as Mollman suggested it would do and as our research has then highlighted as well. So across that intervention interval, we can see that heel, toe and dorsal hoof wall angles become more acute. They become smaller. Medial and lateral walls become more sloped.

Hoof capsule rotates towards the heel, so the sense of pressure moves towards the heel and then there is going to be more heel loading, shifting the weight back onto the horse’s heels. Now remember what we talked about at the beginning in terms of anatomical relationships. What’s that then going to do to the anatomical relationships that we talked about? This caudal or palmar shift of pressure increases the load on the deep digital flexor tendon and its associated check ligaments.

It increases the load on the superficial digital flexor tendon and its associated check ligament, as well as the suspensory ligament and the whole realm of sesamoide ligaments that sit down here, as well as the annular ligaments that sit around here and hold these structures into position. So whilst the distal limb, whilst the foot is of concern, the distal limb then is of concern because we’re altering and shifting the loads that are on these structures.

but then we’re altering and shifting the loads that being placed on the muscle above it, changing the positioning of the limb, that’s going to change the position of the horse’s posture, it’s going to alter the horse’s posture. Potentially, you’re going to get horses that are going to stand with their feet slightly further out in front of them and put them into an extended posture. So you’ve got a lot of soft tissues that are then compensating for this change in alignment. Now, if this is once in a while,

and we have, you know, this regular intervention, it’s four to six weeks, and we can shift that pressure back, that’s fine. But if we’re repeating that time and a time again, or if we’re pushing past that six weeks and going to seven or eight weeks, every single time that the horse is shot, then these soft tissue structures are accumulating excess load at a quicker rate than they can potentially heal from. So any potential damage to those structures, albeit microscopic, might take longer to heal than the time that we’re allowing.

So we’ve always talked about horses that are long sloping past and being more prone and more susceptible to tendon injuries. This kind of explains why really, but also shows that even your horses that aren’t long sloping pastens can be put under the same risk of excessive loading if we allow them to go for too long between shoeing intervals. So we have to ask that…

Whilst increasing intervals by one or two weeks might save a couple of hundred pounds annually, is that really worth it when those risk of our horses becoming injured? And actually the cost of getting them back onto the road and healing them is significantly more than a couple of hundred pounds.

So I was asked after the initial publication to write this up for a couple of journal articles, sorry, a couple of lay articles. So the sort of lay articles can be found in the Horse magazine. There was one that I wrote up for Horse Hub, which is online magazine, as well as the American Farias Journal. And it’s work that keeps kind of resurfacing, particularly now that we, you know,

globally affecting our economic sort of troubles. And therefore it’s something that I really want people to bear in mind because it is something that we can, an area that we can potentially cut costs on. But the impact that that potentially has on our horse, short and long term might negate that quick cost saving. And therefore, actually, if we’ve got a horse that we really want to keep on the road and working.

effectively and looking after its health from a moral and ethical standpoint, then actually that hoof care interval needs to be optimum for them. So in conclusion, we know that the shearing interval of four to six weeks is sufficient duration to result in that shift of pressure towards the heels that increase the loads on the heels. It alters the distal interphalangeal joint angulation to create a more broken back foot. It increases the load on those susceptible structures.

But because of that, it then has a wider and more holistic impact both up the limb, across the back, potentially through the head and neck posture as well and into high and quarter posture. So it has a far wider reaching effect than just the foot. So a four to six week intervention interval will enable the farrier or the hoof care practitioner to correct any of these changes early enough that actually cumulative excess loading doesn’t get chance to cause injury.

and therefore you’re looking after the long-term health of your horses. Thank you for listening and I’d be happy to invite any questions. My email address is also on the slide so please do feel free either to contact me directly or through animal web.