Please remember!

The information presented on this blog represents "learning in progress" on my part, a horse owner, who was not satisfied with professional farriers and took matters in my own hands. As far as I am aware at the time of the post, the information presented is correct, but may change with me understanding more about hooves, in which case I will edit or remove the post. In order to follow my learning and understand everything about Molly's hoof, you need to start reading at the bottom.

Thursday, August 29, 2013

the problem with measuring heel height

I recently had quite dramatic events happening to me and Molly. I try to summarize them here, as far as I understand everything right now.

About 3 months ago, I started to trim Molly according to the HGM method. HGM stands for "hoof guided method". More information about it can be found here. The reason why I wanted to do something different as I always did was because I just could not get Molly to walk comfortably on concrete or asphalt. This statement is not completely true, as Molly usually was comfortable walking on concrete at the end of a trimming cycle, especially when I had been away for a few weeks and did not do anything to the feet. Not even pick them out. Every time when I got back and had not interfered with Molly's feet for several weeks, Molly was cruising over concrete, but when I finished trimming, she did not, but was stiff and careful again on concrete. So at this point I knew that I was the problem with her walking on concrete!

For the longest time I thought this was simply because I trimmed her generally to short. However, as it turns out, this was not the case, I simply trimmed her in the wrong places, and as I know now, I trimmed her lateral heel too short.

The way I fond that fact out was the following. I had started the HGM trim, which basically does not do anything else than beveling the toe, but leaves the heels alone, unless the wall is more than 3-5mm above sole. That was not the case on Molly and so I left heels alone for at least 2 months.

On July 22, Molly had this FL foot:

I liked this foot a lot. Molly and I were riding and riding, for the first time in 2 years she was sound on all surfaces!

Then I made a mistake. I had no experience with this new HGM method and I was too much influenced by other trimming methods, and my feeling was that the heels were becoming too high and needed a trim. The HGM method would still not have trimmed those heels, as the sole was right up there at heel level. And as I said, Molly was as sound as never before. Nevertheless, I decided to shorten them. In hindsight, it was stupid, BUT I learned a lot from this mistake! And that really is the important thing, learning from the mistakes.

Since I did not really have any indication from the sole how to trim the heels, I resorted to my "heel gauge", that I still have from the times when I followed the ABC trim (which I stopped doing a long time ago, for many reasons I don't want to go in to). However, that little heel gauge I still had used even though I had updated it to incorporate a larger heel height than originally recommended.

This is an example of how this tool works:


The little L-shaped tool is held against the heel (red line) and the tool would then indicate a vertical heel height of 3 cm (in my case).

So I went ahead and marked and trimmed the heels as I used to do, using that gauge on both sides of the hoof.  The tool indicated to me that the lateral heel was higher than the medial one. It also looks like that, when looking at the picture above, and I was convinced that this is what needed doing, shortening the lateral heel to match the medial.

The next morning, Molly was very sore. And I had absolutely not done anything else than shortening the lateral heel, to what I thought would match the medial. She was way worse on her FR than FL. The FR has large ossifications of the lateral cartillages, which the FL does not have, and thus the FR can cope pretty much not at all with an unbalanced foot. And lowering that lateral heel must have seriously unbalanced the foot. I could hardly believe how dramatic the effect was.

The next thing I did then is cut Molly a pad and glued a piece of firm rubber mat under the lateral heel, lifting the lateral heel up to what I thought it may have been before I lowered it. Molly went from looking almost like a foundered horse to walking 99% normal on pasture. Incredible effect, of simply raising the lateral heel. So that confirmed to me that I lowered Molly's lateral heel too much. Unfortunately I don't have a picture. Molly did not want to lift her feet and I was devastated thinking about other things than taking pictures.

Luckily, during the last couple of months Molly had grown rather high heels and I was now in a position to remedy at least some of my mistake by lowering the medial heel too. But I did not have any good trimming guidlines from the hoof, so the whole thing was kind of a mess. Nevertheless Molly was ok with the lowered medial heel, which kind of restored the heel proportions to before I did anything to them. After 2 weeks I started to ride again and Molly is almost back to what she was before the mistake.

But for the last weeks I have been trying to figure out why this heel measurement does work so badly on Molly and why my visual judgement of the heel height also failed me. Many people trim the heels back to the widest part of the frog, and Molly's lateral heel was definitely ahead of that landmark, and much more so than the medial.  I was by then pretty convinced that this must have been my problem all along, unbalanced heels after my trim.

The explanation I came up with is shown below, as a model. What I realized is that the lateral heel is different from the medial in the fact that it grows at a more shallow angle. The medial and the lateral side of Molly's hoof (and almost all domestic horses) are not identical. The medial wall angle is usually more upright. I think as a consequence, the medial heel also grows at a steeper angle. I have never read about that fact, but I am pretty convinced it is true on Molly (and also on Gus), and I had actually noticed that phenomenon earlier, just never realized what it means with respect to shortening the heels using a measurement.

What happens to the heel height, when the gauge is applied to heels that grow at a different angle, is shown above. Of course the tool is supposed to be hold vertically, but in reality, this is pretty much impossible with the hoof in hand, nor is it emphasized anywhere in the ABC protocol. In my case, I just held it to the medial heel as I did hold it to the lateral heel.  But this procedure leaves the lateral heel with a too short vertical height, IF the heels grow at a different angle, as is the case on Molly.

Since I am always studying the hoof wear patterns on Rockley Farm horses, I began to notice that the same phenomenon, as I observe on Molly, happen to the Rockley Farm horses, when they are allowed to self trim and grow their feet as the like. Below is a picture of Paddy, taken from the Rockley farm blog.

This is Paddy's front left foot, after 8 weeks at Rockley farm, self trimming. What I noticed is that the lateral heel, just like in Molly's case, grows forward. I have marked the heel purchase in green on the right side of the picture. Yet, when sighting the hoof from behind, if anything, the lateral heel is lower than the medial. This is because of the shallower angle it grows at.
Again, my observation is that when Molly's lateral heel has grown forward, in a similar way than Paddy has grown his heel, she is SOUND, when I take the heel back, to the widest part of the frog she is stiff on concrete. That must mean something, I would think! And obviously, Molly is not the only horse who grows her feet like this.

In any case, I am back with the HGM, now waiting patiently until the heels show me any indication for wanting to be trimmed.


  1. Kewl! Thanks for that. So when you do your next trim, perhaps you could measure the vertical heel heights the old fashioned way to see how high her heels need to be to stay sound on concrete? I don't much like the idea that ALL horses should be trimmed to 1 1/8 inch heel height on ALL feet. I would also be interested to know if the heel heights are the same before trimming to live sole and of course after trimming to live sole. There are quite a few mustang pictures floating around now where the heels are not 'self-trimmed' back to the widest part of the frog.

    1. First it's 1/4 inch above the sole, and second, why not? No one seems to have a problem with trimming down to the sole - which often makes horse sore.

  2. Hi Josie, I am not 100% sure I understand what you mean:
    "I would also be interested to know if the heel heights are the same before trimming to live sole and of course after trimming to live sole."
    Can you try and explain?

  3. If the sole is not giving you any guide to trimming the heels, it's telling you NOT to trim the heels. It really is that simple.

  4. Molly, I'd like permission to use some of your mustang hoof photos, because as Josie noted, all mustangs do not self-trim as people are teaching.

    1. sure, please go ahead. On which photo do you think they are not self trimming?

  5. Maureen, have you noticed that horses grow lateral heels more forward, than medial, generally? Off course not all horses will do that, but is there a trend?