Half a Trim?

Front View

A client of mine recently pointed me to the website of another “natural” hoof care practitioner. Always hoping to learn something new about the equine foot, I visited the site and did some reading about her trim philosophy. Wow! What a disappointment. Although what she describes definitely has some elements of proper trimming, her philosophy is marred by an incorrect understanding of the forces at work on the hoof. She builds a series of arguments in defense of her philosophy upon a flawed premise, throwing in bits and pieces of “scientific facts” that are anything but scientific in an attempt to rationalize a trim that’s anything but natural. Most amazingly, she offers up as “proof” a series of photographs of a hoof that, to me, clearly show an increase in hoof distortion because of her trimming! And so, at the end of the day, like countless others who’ve jumped on the “natural” bandwagon, she’s advocating a trim distinctly at odds with true natural hoof care and potentially harmful to her clients’ horses.

Bottom View

Unfortunately, I have neither the time nor the space here to address all of my concerns with her approach to trimming, but another client’s delay in getting her horses’ hooves trimmed ended up giving me a convenient way to describe what I see as the major flaw in this trimmer’s philosophy. This fault, which is shared by many others, centers on the notion that “natural” hoof care involves not trimming some particular part or parts of the hoof. For some, it’s the sole; for others, the bars or frog. In this person’s case, it’s the heels. She states: “While the advice of many is to trim the heels, my advice is to leave them alone.”

The role of the natural hoof trimmer is to provide the trim nature provides; specifically, to trim the hoof as nature would trim it given the right circumstances. We have very clear examples of the end results of nature’s trimming, and can see the effects of the abrasive forces at work on a consistent, whole-hoof basis. Yet, somehow, these folks manage to separate out various parts of the hoof to trim or not trim, based on criteria that are frankly beyond me. I’ve heard some very well-known trimmers make remarks like, “If I trim a hoof and part of it grows back quickly, then I figure the horse must need that part to be long, so I don’t trim it again.” Huh?

In this particular trimmer’s case, some of her comments lead me to believe her “no-heel-trim” philosophy is based on the fact that different environments produce different hoof forms. Take a look at the illustration below –

Ovnicek Environment Effects

– from New Hope for Soundness, Second Edition, by Gene Ovnicek

Given sufficient movement over suitably-abrasive terrain, every horse’s hoof will look like the bottom illustration, just as documented prior to Mr. Ovnicek’s efforts by Jaime Jackson. As the terrain gets softer, less and less abrasive forces are at work on the heels, and so they grow basically unchecked. But, as noted in the illustration, the hoof maintains the same functional angle because the heels penetrate the softer terrain. So one might conclude, as I suspect this trimmer did, that since many of our horses are kept on softer terrain, the heels should be left alone.

Examine the two photos at the start of this post. In the second photo, the red horizontal lines on the left half of the photo mark the ends of the toe and heel buttresses (“heels”). The red lines on the right are equidistant from the left-hand lines, and mark the trimmed position of the heels and an equivalent distance back from the untrimmed toe position. This helps illustrate the important concept that trimming isn’t just about shortening the hoof in the vertical direction; as you can see, the trimmed “footprint” of this hoof has actually moved towards the back of the Excessive hoof length illustrationhorse approximately 10% of the length of the foot, correctly placing the weight of the horse forward over his heels. So excessive length of the entire hoof, even if it’s balanced front-to-back (A-P) and left-to-right (M-L), is ultimately harmful. For a better look, check out the accompanying illustration – a revision of the one that appeared in Hoof Angles – Part 3 from Dr. Deb Bennett’s Principles of Equine Orthopedics. Incidentally, note that the contact point of the toe, indicated by the green line, has actually moved even farther back, somewhat shortening the “footprint.” Most, if not all, of that decrease is due to the “mustang roll” around the outer hoof wall. You can also, by the way, get a pretty good idea from the photo about what would happen to the “footprint” if we trimmed the toe and didn’t trim the heels!

That’s enough about why we trim the hoof, but I need to say more about why we trim the entire hoof. There’s a reason why there aren’t, and shouldn’t be, region-specific “natural trims.” And the reason is quite simple –

Trimming the hoof as if the horse lived in the extremely abrasive environment of the U.S. Great Basin, traveling many miles per day, will always offer every horse the best chance at long-term comfort and soundness because the worst-case riding environments we subject our horses to most closely mimic those conditions.

To say it another way: when we ride our horses on pavement, hard ground, or even well-packed sand, the heels cannot adequately penetrate the surface. So if the hoof isn’t properly balanced for a flat landing on an unyielding surface at the walk, the foot will be subjected to the damaging forces of jerk and concussion, as described in Hoof Angles – Part 4. So the practical form of Mr. Ovnicek’s illustration should look like this –

Ovnicek Comparison

Hooves kept on soft terrain and ridden on medium-hard or hard terrain

We cannot – we must not – pick and choose what parts of the hoof to trim or not trim, because the U.S. Great Basin feral horse model, combined with a bit of common sense, shows that to be wholly improper. And deliberately unbalancing the hoof, as advocated by the aforementioned trimmer, can have very dire consequences for a horse unless the horse is always used in exactly the same environment the trimmer has catered to in his or her trim (highly unlikely, I might add!). The safest and healthiest trim for your horse will always entail removing all excess growth, and not a bit more, as demonstrated by the U.S. Great Basin feral horse model.

In closing, I want to share an excerpt from a video I’m working on. The first clip is of one of my clients’ horses, chosen only because of the wide concrete barn aisle. As you’ll see, the horse lands flat at the walk. The second clip, which I did not record, is of a horse whose trimmer had been mimicking the trim style he saw in a well-known book on natural hoof trimming – or so, at least, he and the owner believed. Note how the hooves, most notably the front ones, literally slam into the ground heel-first. Ouch!

Landings Clip First Frame

– excerpt from an upcoming video about proper versus improper landings, showing the flat landing of a properly-trimmed horse followed by the heel-first landing of an improperly-trimmed horse

More soon…

Comments

  1. Sandy Judy says:

    I was confused by your video as the first horse landed flat-footed (improperly), and the second horse landed heel first (properly). The second horse looked as if it were trimmed properly while the first horse looks as if it had not been trimmed on the fronts and had high heels while the hinds looked like the heels were low and toes were long.
    While there are many trim styles out there, I think the second horse will have less problems than the first horse. MO

    • Steve says:

      It’s a very common misconception that a horse should land heel-first. However, it’s simply not logical for a couple of reasons. First, the hoof, which is softer than the abrasive terrain on which it moves, will necessarily wear the hoof to land flat at the horse’s most common gait, which is the walk. Despite what anyone else may say, it cannot be any other way. Look at the photos of feral horses living and moving on extremely-abrasive terrain to see how very short their heels are – in fact, their entire hoof is extremely short. And second, we know that the jerk and concussion that result from a non-flat landing stimulate the conversion of connective tissue to bone. That would seem to further support the idea that the horse must land flat, since I cannot imagine an animal whose very life depends on a strong, healthy hoof would be “designed” to be self-destructive in that manner.

      I believe the misunderstanding comes from a misinterpretation of a comment by Dr. James Rooney, in which he says the horse lands flat or very slightly heel-first. He does not address the horse’s gait or speed in his comment, however, which may or may not be a factor. He also made that comment many, many years ago, when I would guess that nearly every horse he would’ve observed had excessively-long heels. A well-known hoof trimmer seems to have seized upon the “heel-first” part of Dr. Rooney’s comment, and quotes only that part of it in his clinics (I’ve heard it myself); therefore, many people out there mistakenly think it’s how a horse should land. I understand, incidentally, that that person has since changed his position in his new publication, and now concedes that the horse must land flat at the walk, although I haven’t read it myself.

      What matters to the horse, as I’ve pointed out in several posts, is that his bones/joints line up properly when he’s standing. That’s ultimately what determines how the bottom of his foot must be trimmed. Thus far, every freshly-trimmed horse I’ve trimmed for a proper (flat) landing that has been radiographed has had his coffin bone in the proper relationship to the ground and his bones/joints in proper alignment. I can think of no better evidence than that.

      The two horses in the video are actually trimmed the opposite of what you stated. The first horse has very low heels (compared to the second one), and therefore lands flat because he’s properly balanced. The second horse has excessively-long heels with respect to the toe, and therefore lands heel-first. This is another common source of confusion; since the horse does not correct the flight arc of the hoof according to how the bottom is trimmed (just as you don’t correct the flight arc of your foot according to what type of shoe you’re wearing), whatever has been left long necessarily strikes the ground first. Hence, a heel-first landing is caused by excessive heel length.

      And just so you know…the first horse, who has been a client for several years, has always been very sound. The second horse, however, is dead lame, which is what made the owner seek my advice, and why I asked her to send me a video of the horse. Even the veterinarian who examined the horse noted in his report (much to my surprise) that the heels were way too long.

      Thanks for your comments.

      Steve

      • ALISON says:

        So do you agree that heel landing is preferred at higher gaits on flat unyielding surfaces with the perfect trim. This is my understanding.

        • Steve says:

          Sorry, but I don’t have enough data (yet) to answer that question. But, logically, a heel-first landing is undesirable at any speed, as it eventually leads to DFT and navicular bone arthrosis i.e. navicular disease.

  2. LJackson says:

    Amazing post. Your article deftly explains the mechanics of a horse. There is no argument to the mechanical science of a horse’s movement. The patience you exhibit in attempting to educate horse owners is to be commended. Thank you for being my farrier!

    • Steve says:

      Thanks for your very kind words.

      It’s admittedly a challenge to try to present material that can be somewhat technical in an easily-understood manner, and I’m glad to hear I’m making my point! But in reality, many of the issues horse owners seem to get hung up on are actually very simple concepts that have been obscured and complicated by the horse world through some fundamental misunderstandings that continue to be perpetuated by well-meaning but ignorant people. In my (technical) world, everything has to pass a “head and gut” test; if it doesn’t quite make sense, and it doesn’t “feel” right, guess what? It probably isn’t true. But there’s an awful lot of that type of “information” circulating in the horse world, making it extremely difficult for horse owners to sort out truth from fiction. I’m working on a post that discusses this subject more at length, by the way.

      Thanks again.

      Steve

  3. PR says:

    Should every horse be trimmed like example A in the illustration “Trim indicates comfort and soundness”, having the heel back under the leg? This is what I thought and asked a farrier about that. He said yes on some horses and no on others, explaining why. I don’t remember understanding the explanation. My horse has the heel slightly forward and I’m working on bringing that back and the toe back… the whole hoof back about 1/4″. I just want to make sure this is the right thing to do for every horse.

    • Steve says:

      The short answer is “yes,” but I very much need to emphasize that the appearance of the hoof in “A” is the end result of proper trimming over what may be a considerable amount of time, and is also highly dependent on the conformation of the particular horse. This is the problem with hoof care providers who don’t understand that hoof form is the consequence of movement, and not the cause. If you were to attempt to trim every horse’s hoof to look like “A”, you’d end up with some very lame horses, because many, many horses have a much more upright pastern (while some, like my Paso’s, are much more sloping) than the one depicted in “A”. So you have to make certain you understand what you are and aren’t looking at in “A”. What you are looking at is a hoof trimmed to follow the live sole contour to a consistent white line depth, resulting in: 1) proper alignment of the bones below the fetlock, 2) a base of support that’s as far back as possible under the limb, and 3) a flat landing. What you’re not looking at is a particular hoof angle, pastern angle, or hoof length. Those characteristics are the consequence of proper trimming, and, therefore, optimal movement. They’re not the cause.

      Thanks for your question, and best of luck with your horse!

      Steve

  4. Alison Ball says:

    Very interesting. Thank you Steve. One question. What do you consider to be normal relationship between ground and P3?

    Alison

    • Steve says:

      Hi Alison –

      Great question! I assume you’re talking about the A-P relationship. I think the generally-accepted textbook relationship of a forward “tilt” of between 3 and 6 degrees is probably correct, although I’d love to do a study on the subject. I do know that when my clients have their horses radiographed, their flat landings occur with angles in that range. Interestingly, many vets don’t know what that shallow an angle actually looks like; I’ve had to overlay protractors on radiographs to show vets who claim the heels are too low that the coffin bone angle is, in fact, right “on the money!”

  5. Wanda Colburn says:

    Thank you for your incredible explanations!!!

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