Mistaken Identity

Over the past several years, I’ve seen a considerable number of lame horses that have been diagnosed as having one problem or another but in reality have a very different one. And a visit a few weeks ago was no exception. I went out to trim a horse who’d been diagnosed with sidebone – the horse I mentioned in the post entitled What Makes it “Natural Hoof Care?” – and discovered that while he does, indeed, have some sidebone palpable in the lateral lateral cartilage (the one to the outside of the hoof) of one of his feet, it’s not his biggest problem at the moment.

Sidebone, just to remind you, is caused by excessive unilateral concussion – the horse repeatedly banging down on one “side” of his hoof. Since this horse’s conformation is such that his front feet point slightly toward the outside (as many do, especially in the hind legs), I’m sure someone tried to “fix” him by leaving the lateral (outside) wall longer than the medial (towards the horse’s mid-line) side. That’s the “time-honored method” advocated by many veterinarians and used by farriers everywhere to attempt to straighten “problem” legs.  In reality, the only thing it’ll straighten is your wallet as you open it to pay for work that ultimately compromises the long-term (and sometimes short-term) soundness of your horse! You cannot fix at the ground that which originates in the shoulder or hip. Unbalancing a hoof can only cause harm.

That said, I seriously doubt this horse’s sidebone will prove to be much of an issue at all, but we won’t know until the more immediate (and, unlike the sidebone, treatable) problem is resolved.

This horse, like the one I described in Progress!? and Progress Update!?, has a fairly serious infection in the central sulcus of the frogs of both of his front feet. If unrecognized and untreated, these infections can go deep into the frog, invading sensitive tissue and rendering the horse quite lame. Of course, that always leads to the question of how/why the veterinarian and farrier missed such an obvious (at least, to me) problem. I’m not, by the way, critical of the horse owners in such circumstances, because: 1) I have no reason to believe horse owners should necessarily recognize what’s normal for a hoof, and 2) I understand why owners assume they can rely on their vets and farriers to recognize what’s normal for a hoof.

How can you tell if your horse has such an infection? Well, in a healthy hoof, the central sulcus isn’t very deep; it generally looks more like a fairly broad “dent” in the middle of the frog, as if someone had pushed his/her thumb into it. Check out the photos in some of the other posts to see what I mean. The infected frog, on the other hand, has a very deep groove, hole, or “split,” often extending out the back of the frog. The hoof pick will go deep into the groove – a half-inch or more – and bring up a malodorous black “goo.” The horse will usually react to the pick, since the infection has invaded sensitive tissue, so be careful! A sure sign of the problem is when you note a dark line running from the back of the frog up between the heel bulbs and above the hairline. The central sulcus of a healthy hoof will never extend above the hairline. This can often be seen while the hoof is still on the ground, especially on horses with white legs. And scar tissue is often visible on horses who’ve had this infection in the past, appearing as a hairless line or inverted “V” above the hairline between the heel bulbs. The following two examples are of relatively minor cases; the horse in the first two photos is not yet showing any lameness, while the horse in the third photo is beginning to show a mild lameness. These were taken on my first visit: the first two post-trim, while the third before any work was done –

What, exactly, causes it? I don’t know for sure. But what I do know is that it’s most common during wetter times of the year, and that only certain horses in a group will get it, even though they’re all standing in the same mud. Clients ask me if it’s thrush, and I honestly don’t have an answer to that question because I’ve seen equine medical books describe thrush as both a white fungal infection of the frog and a black bacterial infection of the frog. In people, thrush is definitely a white fungal infection (of the mouth and tongue), so my inclination is to say “no, it’s not thrush.” There are a tremendous number of organisms – of all types – present in the soil, and I have no idea which one or ones are responsible for these infections. I do believe it’s bacterial, however, because it definitely responds to certain antibiotics.

It’s usually fairly easy to treat, although it can take a long time for the damaged tissue to regrow. Bearing in mind that I’m not a veterinarian, I generally have clients begin treatment with liquid Lysol mixed according to the bottle directions, and sprayed or poured onto the clean affected area once a day for 2 weeks. Depending on the severity of the infection, I also sometimes recommend making an effort to keep the foot dry with (preferably) a boot or limited turnout. After 2 weeks, there should be a noticeable improvement – the odor should be gone, sensitivity should be reduced, and new tissue growth should be apparent. If not, then I recommend the daily application of either of two over-the-counter topical antibiotics made for bovine mastitis called “Cefa-Lak ToDAY” or “Cefa-Dri ToMORROW” for 2 weeks. My clients report great success with this drug; as long as the horse isn’t perpetually reopening a very deep wound through the natural heel expansion that accompanies movement, there will be a definite improvement. In very severe cases, we’ve also had to restrict either movement (through stall rest) or hoof expansion (using boots) to get the wound to remain closed and heal.

One thing I don’t recommend is using some of the harsher chemicals people often use on feet, like chlorine bleach. It’s important to kill only the disease-causing organisms, and not new tissue growth. And, so far, the treatment outlined above has worked just fine, so my advice is to stick to it.

These cases apparently baffle many veterinarians and farriers, and every case I’ve seen has had at least one of each look at the horse prior to my involvement – sometimes several of each. Besides the sidebone case mentioned here, other misdiagnoses include laminitis/founder, pedal osteitis, and “navicular.” In a number of cases, the problem has been somewhat masked by shoes, often with full pads. Covering the sole with a pad, especially in conjunction with silicone poured between the sole and the pad, is particularly problematic because it traps moisture and seals out air, making a practically ideal environment for the offending (and often anaerobic) organisms to thrive.

So the next time you hear of a lameness issue, maybe you can pass this on to the horse owner. The real cause may end up being a relatively pleasant surprise!


  1. kelly says:

    I see so many horses with this and no one tells owner to treat it because they do not recognise its there . I have pointed it out and then owner asks farrier and and farrier says no its ok. Very frustrating !! Thank you for posting. The product Hoof RX works great as well .

  2. Steve says:

    Thanks for your comments, Kelly. Yes, it’s got to be very frustrating for a horse owner to spend time and money on vets and farriers and have them either diagnose and treat the horse for an entirely incorrect condition, or not diagnose a problem at all. I have one client whose horse suffered with an absolutely crippling case of this infection for a year. She’d had at least one vet, and several farriers, tell her there was nothing wrong with her horse, even though he was extremely sore! The only reason she found out what it was is because I overheard her struggling with the horse one night over trying to lift his feet, and when I leaned out of my horse’s stall to see what was going on, I could see dark lines running up the backs of his legs above his heels.

    On another occasion, I lost the battle with a horse owner (actually, her horse lost) over a very severe case of this infection because the area’s leading “expert” leg vet told her the horse’s problem was pedal osteitis due to being barefoot, in spite of my repeatedly pointing out the infection to her. And, I might add, in spite of me previously saving one of her horses from founder when the very same vet told her there was no hope for the horse and recommended putting him down!

    The fact is, horse owners tend to place their confidence in veterinarians. While I won’t get into the whole subject in this note, let me just say that, logically, what percentage of their 6 – 8 years of education in veterinary medicine (a very large subject, indeed) do you suppose is spent on equine hoof disorders? Seems like I’d tend to believe the guy who’s spent, at this point, 18 years studying nothing but hooves and hoof problems…

    • kelly says:

      I am happy that my horses are barefoot and sound …I thank you for that ! I spent years and oodles of money on farriers making my horses sore and knowing something wasn’t right but getting no real answers from socalled professionals . Only through the horrible circumstance of Hooray falling head over heels from the pain in his shod feet did I start to realize that there had to be another way. After reading about all the problems shoeing can and does cause I started studying about horses performing barefooted (is that a word?) I then came across you when I learned there is a difference between trimming a horse naturally and what farriers do as a “barefoot’ trim which leaves horses sore and then they say “you better put the shoes back on” . Long story short I will always have barefoot horses! Hooray thanks you as well . Have fun teaching and see you next week!

  3. Belinda Borders says:

    A very good series of articles was published in The Horse’s Hoof about healthy frogs and recognizing infected frogs and sulci. You can view them online at thehorseshoof.com. As an average horse owner I didn’t realize that thrush could take on so many areas of the hoof and what devestation it could bring.

    • Steve says:

      Thanks, Belinda, for sharing that with us. But I do want to point out that, of the many, many hoof infections I’ve seen thus far, none of them have been thrush. These infections are apparently bacterial, and thrush is a fungal infection.

  4. Sandy Judy says:

    Since the circulation (blood vessels) to the frog has got to heal the frog from within by growing new tissue and fighting infection, it is important not to impede this circulation. High or long impacted bars will squeeze upward, cutting off this circulation. I advocate, in addition to the info here, trimming the bars. Sometimes it seems as if you have to dig the bars out and this does make sense if the bars are impacted. But many hoof trimmers are not trained to do this so they don’t advocate it.
    As an aside, my daughter had a rash that was driving her crazy. She went to a dermatologist in addition to her regular doctor. Both misdiagnosed the rash. But the lactating nurse correctly diagnosed it as a rash that is common and associated with nursing a baby, which she was doing.
    So even specialists can make some mistakes in diagnosis. It is important for vets to look at the obvious first.

    • Steve says:

      Yes, it’s absolutely crucial in trimming to remove all of the “junk,” and that definitely includes excessive bar growth. That was assumed in my post because I have not (yet) comprehensively described the trimming process on my website, mostly because I don’t want to give the impression that I believe horse owners should attempt trimming their horses without adequate instruction from a highly-qualified source. And that doesn’t include some “how-to” plan on a website! You’re certainly correct that many trimmers don’t remove enough bar (or sole or frog, for that matter). There are far too many people out there who read a book or two and think they know enough to go trim horses, much to the detriment of the horses! Again – proper instruction is necessary for good results. Thanks for your comments!

      • Sandy Judy says:

        Since I have been trimming for 10 years, and attended the 2005 SHP hoof professional’s course and several clinics with SHPs prior to the course, I feel I received as proper an education on the hoof as was available world wide at the time. I still have my SHP “student” status because I have yet to pass the final exam due to disagreeable terms. I just didn’t feel it was worth the additional expense to retake the test when the questions I answered incorrectly were politically charged.
        But my real education continues with each horse I trim.:-)

        • Steve says:

          And that’s the real lesson I believe every trimmer should pursue – the opportunity to learn with every trim we do. Thanks for your comments.

  5. Franco says:

    I’m sure someone tried to “fix” him by leaving the lateral (outside) wall longer than the medial (towards the horse’s mid-line) side. That’s the “time-honored method” advocated by many veterinarians and used by farriers everywhere to attempt to straighten “problem” legs.

    May you check it? The farrier method in case of toe out should be: the medial wall from the quarter to the toe higher than the lateral wall. The opposite if toe in. Not much, 1/16, just in an attempt to discourage outward or inward rotation.

    Thank you for the very interesting posts!

  6. Nancy says:

    Hands down, the best for this type of “infection”, is Clean Trax. My t-bred mare is prone to these for some reason, despite efforts to keep her pasture and run-in clean and dry. I’ve tried everything, the Dry Cow, the Lysol, the diaper rash ointment mixed with antibiotic cream….but usually one hour-long soaking with Clean Trax cures it.

  7. Susan says:

    So thankful for this blog…as well as pictures.
    My horse came to me from a very wet region. The farrier said he had thrush…which I treated over & over. Every time I asked him…is it getting better…he said don’t worry about it. Fast forward a few months…
    My horse starts tripping. And by tripping I mean going down on his knees at the walk. Sometimes with me on him. Once he somersaulted in pasture at the trot…head over heels. I thought he broke his neck.
    I have three different vets out. Both I mention the possibility of thrush…etc. I get blown off…I get ..Oh, he’s just lazy. From another I get that he probably has arthritis. (he’s 8).
    He was pretty much unsafe to ride for a year. I had 4 farriers look at him…none of them mentioned that his feet could have deep sulcus thrush.
    I did not give up on him…and through months of research, trying different options and your blog I realized that he had severe deep sulcus thrush. To the point that I could insert my whole hoof pick into the crack.
    Not one of the vets or farriers ever mentioned that this could be a problem.
    My horse was tripping because he was walking on his toes…he could not load his heels. While glad that I finally figured it out…I was furious that I had spent several thousand dollars to figure it out by myself. He had probably had it for years before even coming to me.
    I did a soak with CleanTrax and then Tomorrow for two weeks. (as any other thrush medicine and even Tomorrow did not really touch it..)
    His frog was so rotten that it eventually shed and fell off. He had it on all 4 hooves…the front two being the worst.
    So thank you for educating us

    • Steve says:

      You’re very welcome, Susan, and I hope you continue to get a handle on your horse’s infection. These infections can be absolutely crippling to the horse, and I continue to see them undiagnosed and misdiagnosed.

      For example, I was recently called upon to examine a young horse used only lightly for casual riding who came up lame. The vet diagnosed the horse with navicular disease, which, given the horse’s history, would’ve been (in my opinion) extremely unlikely. The vet told the owner he needed to have “special” shoes and pads put on, and so the owner spent a year, as well as a lot of money, waiting and hoping his horse would show some sign of improvement, which she never did.

      After getting the horse’s history over the phone, it took only a couple of minutes of examining the horse to confirm that the horse had, in fact, very serious infections in all 4 feet. So the owner’s very reasonable question was, “Why did the vet not recognize the infection when he examined the horse, and how did the farrier look at these feet every few weeks for a YEAR and not recognize it?”

      Great question, right?


  8. Oriana says:

    I live in Portugal,and trim my own horses feet. One horse has always had contracted heels.This means that the central sulcus is deep, and prone to what I call thrush. He has never been shod, and I have owned him since the age of 3.I find the best way to treat this type of infection is to keep his feet cleaned out every day, and also spray with a mixture of Listerine, cider vinegar, and eucalyptus or tea tree oil.Cutting out the diseased bits helps open the area. The bacteria dislikes air.I do use Cleantrax when I have to, also some of the Red Horse products.The immune system of this horse is not good, and so I have had to accept what is.Both my horses are on a no grain diet, with mineral supplementation done from forage analysis.

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