Recognizing A Chronic Founder, and How To Trim for Rehabilitation
Toni Pacey-Miller wrote to me from Australia several months ago: 'I hope you may be able to give me some advice on my pony's feet. They have been trimmed every 6 to 8 weeks by a farrier for the two years that I have owned her; they were already
very bad when I got her.' Looking at the photos, it was clear that the pony, Muffy, has been chronically foundered and that no-one had recognized this and therefore nothing was done to rehabilitate her feet. Ponies weigh so much less than horses that they may seem less lame and sometimes don't go into the typical 'founder stance' with the front feet placed far forward. This pony was moving around without the extreme pain that we would expect when we look at the photos. Many ponies have feet that look something like this, through neglect or infrequent trimming, or because neither owners nor farriers recognize that they are foundered.
I marked Toni's photos, showing what she could do to begin healing the feet. As she is completely new to hoof trimming, she was cautious about doing too much in the beginning. She sent photos after her first trim, and again I marked to show what she could do next.
I will use Toni's photos to point out some major clues to chronic founder, and explain how we can trim a foundered hoof to make it immediately more comfortable and to get it started on the road to complete rehabilitation. I hope that seeing all the photos together will give you a more 3-dimensional understanding of what is going on in a foundered hoof.
Photo 1. Here is Muffy with Toni's 9-year-old stepdaughter, Kaleisha, showing what a small pony we are dealing with.
Photo 2. This is a side view of Muffy's left front foot. All four feet looked about like this; the hind feet were slightly less deformed than the fronts. It is not a direct side view, so the marks I will make are only approximate.
The first things we see are the toe which has flared way forward, and the overgrown heel. Notice that the growth lines in the hoof wall are wider at the heel than at the toe. This is because the ground 'pushes up on' a flared toe, forcing the wall upward against the coronet where the toe wall is forming, therefore slowing the growth of the toe.
Photo 3. I have marked some less obvious landmarks. The arrow points at a bulge just above the coronet, where the P2-P3 (short pastern bone/ coffin bone) joint is flexed because the coffin bone has rotated.
I drew a 'new toe line' following the direction of the new growth in the toe wall, visible just below the coronet. All of the toe that is beyond this line is flared, and the difference between the existing toe and the 'new toe line' shows how much the white line is stretched.
I drew a 'new ground line' to show about how much the heel needs to be shortened. The actual amount will be decided when we look at the sole.
Then, using these two lines as guides, I drew approximately where the coffin bone would show in an x-ray. It's close to the toe line because a pony's hoof wall is fairly thin; I have drawn in a thicker sole but that may not be exact.
Photo 4. Here the photo is tilted to show the 'new hoof' as it will be after rehabilitation. It's easier to see how the foot has become deformed - the flared toe and the overgrown heel.
Photo 5. Here are the 'new toe angle' and the 'new ground line' to use as guidelines. We will trim to the new ground line (guided by the level of the sole in the seat-of-corn). However, if we rasp off the entire toe flare all the way up the wall, the hoof will be very weak and will likely fall apart completely. Instead, we can use a vertical cut - the short line on the toe - to get rid of the flare at ground level, where it most hinders the horse, while keeping the upper wall for strength. It is a 'vertical cut' because it is at a right angle (about 90 degrees) to the 'new ground line'. We begin with a straight cut across the toe, and round it in, around to the quarters, so that there is no 'corner' in the outline of the foot.
Photo 6. Here is the bottom of the foot before Toni trimmed it. I put marks at (my best guess of) the heel buttresses; note that one is farther forward than the other, indicating that the heel on the more forward side is longer; so Muffy has been walking on an unbalanced foot as well as a foundered one.
I drew a curved line at the present edge of the sole. This is not where the sole will be after rehabilitation; it has pulled forward along with the flare. It does give a guideline for beginning to remove toe flare, for someone who is cautious about overdoing the first trim; even removing this much would make the horse a lot more comfortable.
The dark material (arrow) is very stretched, dead white line. Toni was worried that it would hurt Muffy if she cut through it, but it is many months' growth beyond its blood supply and cannot feel anything.
Photo 7. This is the bottom of the foot after Toni's first trim. She has done a very good job of shortening the heels and giving Muffy a new ground line (flat surface to stand on); this will make standing much easier for her. The heels are shortened until the rasp begins to touch the sole in the seat of corn, after scraping away any chalky exfoliating sole in the heel area. Using the sole as the guideline for heel length gives the coffin bone a level ('ground-parallel') position.
I have drawn two curved lines. The one nearest the toe is the present edge of the sole; Toni has shortened the toe a little but there is plenty more flare for her to remove.
The other line shows about where the hoof wall will end up after rehabilitation - a fairly round outline. Probably it will be even rounder as the foot re-shapes itself. A big point that I want to get across is that all toe that is beyond this rounder hoof shape will continue to cause the new wall growth to flare as it grows down from the coronet. So we don't want to take months and months removing the toe flare, because those months are lost time as far as growing a 'new foot'. Any time the toe extends beyond this line, the new growth will flare instead of having a tight white line connection.
(This line is still a safe distance from the coffin bone. If you trim any more, you will get too close to the coffin bone. Watch carefully the color of the white line; if you see the color changing towards pink, stop immediately, and protect the toe for a few days with duct tape or other protection. In a pony foot, this is only a matter of a couple of rasp strokes, even using the soft side of the rasp.)
Photo 8. Side view showing Toni's first trim. Again we can see that she has done a good job of shortening the heel and giving the foot a flat bottom surface that's comfortable to stand on. (Pony heels 'seem' higher or more upright than horse heels because all equine heels are about the same height, but horse feet spread out wider to carry their greater weight, thus the horse's foot looks less upright.)
The new ground line makes it more obvious how much the toe has flared (same thing as how much the coffin bone is rotated). I have drawn in white the direction of new growth in the toe wall; I hope this line helps you to picture the hoof as it will be after rehabilitation.
In black I drew where we can make a vertical cut to about where the toe line reaches the ground. The hatching shows the vertical cut rounded in as far as the quarters. All the non-hatched toe in front of the vertical cut should be removed, and when it's gone Muffy will be dramatically more comfortable - a flare is painful in the same way that pulling your fingernail off is painful.
Photo 9. This is a front view of the hoof before Toni's first trim.
Photo 10. I have drawn three lines. The upper two lines follow the growth rings in the toe wall. You can see how the growth is compressed at the front.
The lowest line is about where Toni trimmed off some flare in her first trim.
Photo 11. Front view after the first trim. The arrows point to some landmarks: Top arrow, the outer hoof wall. Middle arrow, the white inner layer of hoof wall that we call the 'water line'. This layer is very tough and takes concussion well; it is what the horse 'walks on' when the outer wall is worn or trimmed away in a 'mustang roll.'
Bottom arrow, the yellowish 'white line'. You can see the stripes of the laminae. It's very wide (seen as the dark area at the arrow in Photo 6) because it has been stretched a lot as the hoof wall flared away from the coffin bone.
Here are recent photos, four months and about eight, 2-week trims later.
Photo 12. The toe is dramatically shorter than it was. There is a good white line connection partway down the toe wall. Following the new toe angle, we can see that there is still a substantial toe flare, which continues to press upwards into the coronet. This slows growth of the toe; the dashed lines along some of the growth rings show that the heel is still growing faster than the toe.
Although a pony foot will look longer-heeled than a horse foot, it looks to me like the heel can be shortened a little more. If nothing else, it's important to keep up with the faster heel growth.
The black arrow points at the 'founder bulge' in the P2-P3 joint. It is less now than in the beginning, but reminds us that the coffin bone is still rotated away from the wall.
Photo 13. On the sole view we see the same dramatic improvement. The toe is much closer to where it needs to be.
I marked where I think the point-of-frog will be if Toni trims off a flap of excess frog growth. The spot where frog material and sole material join is an important guide for looking at the proportions of the hoof.
Again I marked the heels to show that they can be shortened a little. The curved line shows about where the toe flare can be removed to completely take all wall pressure off the coronet so that the toe can grow down faster and without re-flaring. The dark brownish-yellow material in front of the toe curve is stretched white line. We expect to see it here because in the side view we saw that the lower part of the wall is flared.
Toni is doing an excellent, if cautious, job of rehabilitating Muffy's feet. She reports Muffy is moving a lot better. In another 6 months I would expect Muffy's feet will be in excellent condition.
I hope that now you can recognize a chronically foundered foot, 'see' the rotated position of the coffin bone inside the deformed hoof, and understand how to trim a foot that's deformed in this way, whether or not this severely, to start it on the road to rehabilitation.