White Line Disease
Next to founder and navicular disease, white line disease is probably the third thing horse owners hear about most often in relation to their horses' hooves. A lot of people are told their horses have "white line disease." But what actually is white line disease? A farrier or trimming or veterinary text will tell you that white line disease is a fungal and/or bacterial infection of the lamina. (The visible part of the lamina is what is commonly referred to as the white line.) And when we think of white line disease, we may think of those gross hoof pictures we see in a magazine article...where the hoof is practically eaten away. But is that actually what your horse probably has when you're told it has white line disease? I doubt it.
Let's think a little more about white line disease and about studies that have been done. I put the most trust in the informal "studies," studies done not in a laboratory, and certainly not by product manufacturers, but studies done by people like us...average people with open minds and the common sense to use their eyes and minds. And so, a while back, a farrier decided to do a study on white line disease. He went out to horse after horse who had it, took samples from their feet, rubbed it in Petri dishes, and saw what grew. He found four fungus...but no bacteria. The interesting thing about this is that the fungus were all common fungus, which all horses are probably exposed to every day of their lives. It's not like they were some rare and wierd fungus that an unlucky horse just happened upon and got infected with, but they are fungus that probably every horse is exposed to every day. So...if you think about that fact for a minute, you can see that the fungus is obviously not the problem.
If you've read our article about The Unhealthy Horse, you know that any kind of "disease" represents the failure of the body's self-healing mechanism. There is no better example of this than white line disease. You see, the fungus themselves are not the problem...they're around all the time. A healthy horse has an immune system which keeps the fungus where they belong--out of the hooves. But a horse with a compromised immune system can't repel the fungus, so they gain a foothold and grow. This is actually the case in the gross examples of white line disease which you see in the magazines. Unfortunately though, as is the case with all conventional medicine, the symptoms are treated...that is, the fungus in the hooves. The actual reason for the fungal infection--the failure of the immune system--is not addressed. You see the "success" photo after the treatments...but what you don't see is the hoof a year or so down the road, when the fungus is back. And, it's reasonable to expect the fungus to come back, because what was treated was the symptom (the fungus), when the actual problem was (and remains) a failure of the immune system. If that failure of the immune system is not addressed, it will continue to manifest itself, maybe not in another episode of white line disease, but in some way. It's important to realize here that such white line disease is not actually a hoof problem, but like most hoof problems, is a problem within the horse's body as a whole that manifests itself in the hoof. If you understand that, then it really doesn't make sense to treat it as a hoof problem and focus attention on the hoof, and most of all you see the futility of trying to "cure" it with medication to kill the fungus. Kill 'em today, they'll be back tomorrow, because they're all around the horse.
But, all that aside, most of you who are told your horse has "white line disease" don't actually see hooves that look like the pictures in the magazines. You see something quite different. Hooves like you see in the magazine pictures are actually quite rare. In fact, I've never seen anything like that in all the horses I've worked on. What I see when I get called out to look at a horse that has been diagnosed with "white line disease" is different, and if you've been told your horse has white line disease, probably what your horse has is the same thing that I see over and over again, which is commonly labeled as "white line disease." It is not the same thing as true white line disease like you read about in the magazines, and I think it's a mistake to call it white line disease....but in the vernacular it gets lumped in there with white line disease. This causes alarm for many horse owners. They hear the term white line disease, and although their horse's hooves don't look all that bad at the moment, they have a fear of walking out one morning and finding hooves like the ones in the magazine pictures. And this fear is the reason so many products are sold which are said to cure white line disease. You notice a little deteriorated spot on the bottom of the hoof; the farrier says it's white line disease, so you go to the store and buy one or more of the preparations advertised to cure it. The thing is...the medications probably won't help, at least not in the long term. And obviously they don't, against true white line disease. Think about it a minute....if those medications which you can buy from any feed and tack store are a cure, how in the world did those hooves that you see in the magazine pictures ever get in such bad shape? Why didn't the medication knock out the white line disease long before it reached that point? So, obviously those medications, while they may kill some fungus, don't represent a cure for white line disease. And if you use those medications when your horse is diagnosed with white line disease, you're not only missing the target, you're throwing the dart in the wrong direction.
Why do I say that?
Well, let's think about the white line. (The red arrow in the picture points to the white line.) The white line itself is the part of the lamina that you see underneath the hoof, the line between the sole and the hoof wall. If you've seen my hoof video, you know that the lamina are what hold the hoof capsule together. The lamina basically hold the static part of the hoof (the coffin bone) and the growing, changing, and movable parts of the hoof together. Keep in mind that one part of the lamina is attached to the coffin bone, and the other part is attached to the inner hoof wall. Any kind of shoeing or trimming which causes the foot to forward extend; that is, the area forward of the frog to extend laterally, will cause the lamina to stretch. The picture shows an example of stretched, weak lamina. The lamina stretch because they're attached to the coffin bone, which is solid bone and won't stretch, so as the hoof itself stretches forward at the toe, something has to give...so the lamina stretch. When they stretch, they get weak and unhealthy. Any kind of tissue that gets weak and unhealthy will begin to deteriorate and decay--that is a natural bodily mechanism to get rid of weak and unhealthy tissue. On most horses I see that are said to have white line disease, the problem actually is deteriorating and decaying lamina due to being stretched. And this usually results from hoof maintenance that has caused the toe area to extend laterally. You can use all the preparations advertised to cure white line disease that you want to, but until you address the forward extended toe, you'll fight a losing battle against what you've been told is white line disease. Keep in mind that the problem is not fungus, the problem is not even deteriorating lamina or an extended toe, but the root problem is hoof maintenance that causes the toe to extend laterally.
Occasionally, there is no extended toe, but rather just a generally unhealthy foot due to long term use of shoes, which causes all hoof tissues to become weak and atrophy. However, in either case, the cause of the problem is the same--hoof maintenance that deforms the hoof and causes it to be unhealthy. And in either case, the solution is the same--discontinue the hoof maintenance that is causing the hoof to be unhealthy. There is no magic medication, no magic preparation, and no magic shoeing or trimming technique that will negate the effects of improper hoof maintenance.
If your horse gets diagnosed with white line disease, please keep these things in mind. Also keep in mind that we've seen horses with forward extended toes so long that we think they're normal...but they're not normal. If your horse has been shod for any length of time or trimmed in a manner that trims the sole, especially the sole at the toe area, I can just about guarantee that your horse has forward extended toes, even though to the horse world they may look normal.
