Founder and Laminitis
Founder, or laminitis, is a common problem in horses. The last bone inside the hoof, called the coffin bone, and the hoof structure are attached together by what are called lamina. These lamina can be thought of as velcro, and an adequate way of understanding it is that the inside of the hoof wall puts out one part of the velcro, while the coffin bone itself puts out the other part, and it all gets attached together, like velcro. (Of course that's a simplified explanation and not the scientific way of viewing it, but it's an adequate understanding for our purposes at this time.) When that velcro fails to hold, that is, when the attachment between the coffin bone and the hoof fails, we say that the horse has foundered or has laminitis. Founder occurs most commonly in the front hooves but can and does occur in the back hooves as well.
There are varying degrees of founder. The velcro may fail altogether, or the attachment may just be weakened slightly. On one end of the spectrum, a horse may have a very slight weakening of the holding capability of the lamina and show no noticeable symptoms at all, or maybe show just a little tenderness that gets blamed as a slight "sore-footedness" after riding. Or, a horse may have a moderate weakening and show slight soreness even when not ridden. A horse may have significant weakening of the holding power of the lamina and show soreness to the point where it takes the classic founder stance (front feet parked out in front) or may even lay down and refuse to stand. On the extreme end of the spectrum, the attachment may be weakened to the point where the coffin bone protrudes out the bottom of the hoof. In all these cases, what has happened is that the attachment between the coffin bone and the hoof has failed to some extent.
Much of the pain from founder seems to come from the fact that the coffin bone becomes more or less loose inside the hoof and puts pressure against the inside surface of the sole. The major area of soreness will usually be in a small semicircle a little in front of the tip of the frog. The reason for the classic founder stance is that parking the feet way out in front transfers the weight from the toe area and more toward the heel area. Sometimes the heel of a foundered horse will grow much faster than the toe. As the heel grows, it grows at an angle inward toward the toe, due to the design of the hoof. (Please refer to the video Understanding the Hoof--From the Horse's Perspective for a more detailed explanation of how hoof design affects the way a heel grows.) Since the heel is growing so much faster than the toe, as the hoof gets really long, it looks like the horse is standing on skis. It's important to realize that although it looks like the toe is the problem, since the toe area often looks mashed together, the problem is actually not at the toe, it's at the heel, due to the excessive heel growth. Another major source of pain comes from the fact that many horses develop abscesses during a founder incident. One of the side effects of founder is that it disrupts the blood flow in the hoof, in some cases severely limiting blood flow to the toe and concentrating blood flow in the back of the foot (one reason the growth at the heel outruns the growth at the toe). One of the causes of this abscessing is lack of nourishment from the blood supply, leading to weakened internal hoof tissues, leading to abscesses. The abscess is the hoof's way of getting rid of the weak, unhealthy internal tissue. It's a normal part of a founder incident. Abscessing, in this case, is a symptom of founder. (Please refer to the video Understanding the Hoof--From the Horse's Perspective for more information about abscesses.)
Some horses will have one isolated founder incident, and it will never again recur. Other horses will have what is called "chronic founder," which means either that the horse suffers repeated incidences of founder or that the initial incident never subsides. It is chronic founder that can be devastating to a horse, and it is chronic founder that is so feared by horse owners. There is some debate over whether chronic founder is just one-incident founder "out of control," so to speak, or whether they are two separate conditions.
To hear that your horse has foundered is akin to us humans hearing that we have a dreaded form of cancer, because the prognosis for a foundered horse may not be very good. A founder incident seems to cause permanent damage to the laminar attachment to one degree or another, which means that even after the incident is over, the residual is a weakened laminar attachment. Even after the founder is over, the attachment between the coffin bone and the hoof may never regain its pre-founder strength. This is especially dangerous in situations of chronic founder, because each incident results in further permanent damage, and over time, this damage can reach the point where the laminar attachment may become so damaged that it is no longer viable.
One of the most feared things to hear when your horse has foundered is that the coffin bone is "rotated," which means that the coffin bone has tilted downward inside the hoof and is no longer being held parallel to the ground surface of the hoof. Rotation can be seen on an X-ray and is measured in terms of degrees, or angle of tilt from parallel. The severity of founder has traditionally been measured in terms of degree of coffin bone rotation. The prognosis for recovery has traditionally been seen as a function of the degree of rotation, i.e., the more rotation, the less chance for recovery.
As in cancer, the cause or causes of founder are not well understood. Chronic founder seems to occur more in middle-aged to older horses, those over 10 years old. Certain body types seem to be more prone to founder, such as horses who tend to be overweight and have more fat on their necks. Some types of illness are theorized as a trigger for founder. Some suggest that the stretched lamina on horses who have developed long toes as a result of shoeing or improper trimming may predispose those horses to founder. Others theorize that the restricted movement and lack of exercise and stress to the feet of foals raised in the confinement of stalls or small paddocks may stunt the development of the lamina and predispose the horses to founder. Other theories postulate that horses maintained with high heels are more prone to founder. Recent research by Dr. Pollitt in Australia indicates that, on a cellular level, certain cells associated with the lamina may lose their ability to absorb and utilize glucose, which is necessary for proper cell functioning. This leads to unhealthy cells and weakening of the attachment and thus the founder incident. The cause or causes of the inability of the cells to adequately take up glucose are the subject of debate and are not well understood. Popular theories include the overcomsuption of certain types of sugars found in green grasses, the overproduction of certain steriods inside the horse's body, or a combination of those, or even other, some as yet unknown, factors. The point is that today, at this point in time, no one can say for certain exactly why horses founder. What is clear, though, is that founder is not a disease of the hoof. Founder is a hoof condition that results from some problem or disturbance inside the horse's body that, for some unknown reason, causes the attachment between the coffin bone and hoof to weaken. Founder is a symptom of a larger problem, and the site of the larger problem is not the hoof.
Founder seems to be mainly a problem for domestic horses. Founder has not been observed in wild horses to the extent that it occurs in domestic horses. From this one can conclude that either wild horses are not as susceptible to founder or that the ones who do founder soon die, with the most probable conclusion being that wild horses are not as likely to founder. This conclusion is reached because of the fact that some wild horse herds are monitored, and problems with founder are seldom if ever observed.
As with cancer, the concentration has been on treating founder once it occurs, and a large treatment industry has sprung up around founder. If your horse founders, you have a wide range of opinions and products and treatment options to choose from. One of the most popular current theories about founder is that it comes from the horse eating too much green grass. This is a conclusion derived from studies, again by Dr. Pollitt, that have induced founder by introducing overloads of certain kinds of sugars into the horse. Thus, one of the popular treatment options is to limit the amount of certain kinds of carbohydrates in the horse's diet. Various kinds of medications have been tried on foundered horses, both to counteract the founder process itself and to ease pain. (Medication to ease pain may ease pain but not necessarily do anything against the founder itself.) Various kinds of herbs, herbal remedies, and natural supplements are promoted for use on foundered horses. The main treatments are used on the hooves themselves, as the hooves have traditionally been the major focus of founder treatment. There are many kinds of shoes you can have put on a foundered horse, ranging from shoes that look more less like a standard horseshoe, to shoes that look like a standard horseshoe but with other things added on, to shoes that look nothing in the world like a horseshoe. There are also various methods of trimming used to combat founder, sometimes combined with exercise programs and diet restrictions. If you are or have been the owner of a foundered horse, you know it's not easy to know which option to choose.
One of the reasons for the confusion is that founder is not well understood, and so it's hard to say that this is "right" and that is "wrong." But, I think the main reason for the confusion is that no matter which approach you choose, you can find success stories for that approach, testimonials from people who used it and their horses got better--maybe not totally well, but at least better. You can find stories from people who had tried everything to no avail, until they tried such-and-such method and finally had success. You can even find success stories from people who did nothing--they just waited it out, and it finally went away. Over the years I've run into people who've had success with all kinds of different ways of dealing with (treating) founder. I began to understand that these were the owners of horses who just had isolated events of founder, and that eventually their horses stopped foundering.
The owners of chronic founder horses, however, were not so lucky, for two main reasons. First, their horses either never came out of the foundered state or foundered over and over again ... and this was even though they were using the same methods of treatment that had seemingly worked so well for the people in the group above. Yet just when they thought their horse had recovered, another founder incident would occur. What they found was that each successive incident became harder and harder to treat because of the cumulative damage of all the different incidents. And remember, they were by and large treating the symptoms of founder, not the cause. Since founder itself is a symptom of a larger problem, they were in effect treating the symptoms of a symptom, at least two layers removed from the actual problem.
The second reason they weren't so lucky is because the negative effects of the treatments themselves finally took a toll on their horses' soundness. As stated in the video Understanding the Hoof--From the Horse's Perspective you can do just about anything you want to do to a horse's hoof for a while and get by with it. The bad effects of the eggbar shoes, pads, corrugated metal plates used as hospital plates, and elevated heels could be absorbed by the horse's body for a while and not cause significant permanent damage. That was the experience of owners whose horses just foundered once or twice and then stopped--the treatments weren't used long enough to cause severe permanent damage. But on the chronic founder horses, treatments were used for long periods of time; so long, that the horses' feet and limbs sustained considerable damage from the treatment methods. In effect, those horses had the symptoms of chronic founder plus lameness resulting from the treatments. Usually, though, the owners didn't recognize that and instead blamed it all on the founder. This is the reason so many owners report success with the natural, barefoot methods of treating founder--those methods are still symptom treatments but don't usually cause long-term lameness problems, i.e. other symptoms.
Most chronic founder horses I've seen who were treated long-term with conventional methods had hoof and lameness problems resulting from the effects of the treatments themselves, while the horses who had been treated by barefoot methods didn't have that problem. The conventionally treated horses often had three levels of symptoms--the symptoms resulting from the treatment methods applied to the hooves, which were applied to combat the symptoms of founder, which itself is just a symptom of a larger problem. That's also why owners who switch from conventional to barefoot treatment methods often see dramatic improvement--the detrimental effects of the treatments themselves begin to heal, and what's left eventually becomes just the effects of the founder. And, in milder cases, the problems with the founder itself turn out not to have been as bad as originally thought. No wonder founder is so confusing! The horse exhibits a maze of symptoms, and it becomes hard to sort out exactly what is coming from where. Is the lameness and hoof deformity coming from the founder or the long-term use of the eggbar shoes? It eventually reaches the point where there is so much going on that it's hard to sort out. The point of all this is that if you have a chronic founder horse, many of the problems you might be tempted to blame on founder may actually be resulting from the founder treatments applied to the hoof.
But what if you have a horse with more than a mild case of founder? What if it keeps happening again and again? Some people have experienced success, at least for a while, by limiting the sugar (carbohydrate) content of the horse's diet. This is commonly done by restricting the horse's intake of green grass and sweet feed, but in some cases owners will have hay tested and feed only hay containing below a certain percentage of carbohydrates. Some owners go farther and have more extensive testing done in order to select hay that meets more specialized criteria. While there's no doubt that an overconsumption of certain sugars can aggravate founder, we need to be cautious and follow Dr Pollitt's example by not making too much out of the green grass issue. For example, a woman called me several years ago with a chronic founder horse. Someone had told her that her horse had chronic founder because it was eating too much green grass. The problem was that she had four other horses in the same pasture eating the same grass who were not foundered. Plus, she and her husband had kept a number of different horses in the same pasture for over 40 years, eating the same grass, and this was the first horse that had ever foundered. You can't really expect her to take the statement, "Your horse foundered because of all this green grass" seriously, because she had kept lots of horses there over the years, and this was the first one who had ever foundered. I've seen lots of owners of foundered horses like this woman, and, although I tell them about the studies relating to sugar and green grass, I won't tell them the green grass is causing their horse's founder--I just tell them it may be aggravating it. I regularly drive by a pasture that is at least 20 acres, full of green grass, and one horse lives in there alone. The horse has been in there for years, and I've never driven by and seen it in a founder stance or lying down, so I feel safe in assuming it's not a chronic founder horse. And of all the foundered horses I've seen, the great majority were living in pastures with other horses eating the same grass, yet the other horses weren't foundered. I've seen chronic founder horses improve somewhat when their diet was limited, but at the same time, I've seen horses on a severely limited diet who nonetheless continued to be plagued by chronic founder. This leads me to conclude that among some foundered horses at least, sugars found in green grass may aggravate the problem; which is to say, there is something within the horse that makes it more susceptible than the other horses in the pasture to harm from the large concentrations of certain types of sugars found in green grass. That means that the actual cause of the founder is not the carbohydrate content of the grass, but rather the "something within the horse that makes it more susceptible." Thus, restricting the diet of a chronic founder horse is a symptom treatment.
Although many different types of medications have been tried on chronic founder horses, none has shown consistent results, and that includes anti-inflammatories, medications to improve circulation, and steriods. That doesn't mean that Joe's horse down the road didn't get better after a series of injections of some kind of medication; it just means that no medication has shown consistent results. The same can be said of herbs, herbal supplements, and dietary supplements. Here is a good place to talk about pain medication. While no medication has shown an ability to cure founder, or even help it, pain medications can reduce the pain a foundered horse has. Just keep in mind that it's just a suppressal of the pain, a reduction in the symptom of pain...it does nothing about the cause of the pain. While relieving pain may seem to be the humane thing to do, keep in mind that pain serves a purpose. It deters the horse from standing or moving in ways that might cause further damage to already weakened and damaged internal parts. If you artificially relieve the pain, you might encourage the horse to do things that will cause further internal damage. The same reasoning in reverse can be applied to shutting a horse up in a stall when it's foundered. It could be that movement, when the horse feels like it and chooses to move, is good for a foundered horse, and if you artifically restrict that movement with confinement, you prevent the horse's ability to move when it feels like it. It's probably best to trust the horse's instincts and let it do what it feels like doing.
As far as treating the hoof goes, you can have pads or special shoes put on the horse that will insulate the hoof from the ground and thus provide some pain relief, but those methods are nothing more than pain relief methods and do nothing to promote healing. They will, in the long run, lead to hoof deformity and lameness problems regardless of what happens with the founder. There are also shoes which are specially designed to support certain structures underneath the hoof or relieve tension on certain tendons and ligaments with the aim of preventing, halting, or reversing coffin bone rotation. If you prefer not to use shoes, there are various methods of barefoot trimming used to treat foundered hooves. All these methods have success stories. But, in addition to all the success stories which you hear about, there are horses who were treated by people with the (often self-proclaimed) reputations for being the best in the business, but without success. You just don't hear as much about the ones that didn't turn out well. The bottom line is that at this time there is no magic solution for foundered horses. There are lots of different treatment methods available, and they all have their success stories ... and failure stories, which naturally aren't publicized like the success stories. And keep in mind that all these methods are symptom treatments. For a more detailed discussion of success stories, please read the manual Maintaining a Natural Horse.
At this time, then, no one can truthfully claim to understand founder or be able to consistently treat it successfully. Founder is a symptom of a larger problem in the horse's body. What happens in the hoof during founder is a result of something amiss inside the horse as a whole, a result of something in the horse's body negatively influencing the hoof. The popular treatments for founder treat the symptoms of founder--either the horse's inability to process the sugars found in grass, or the pain, or other symptoms in the hooves. But even the personalities who have latched onto the results of a certain study or studies and run out into the world claiming that they have found "The Answer" have not had consistent results dealing with chronic founder horses.
Two things should stand out to us--wild horses have less problems with founder, and some symptoms blamed on founder are actually caused by common treatments rather than the founder. So, with our limited understanding at this time, it would seem that the best we can do is try to maintain our horses as close as possible, in all respects, to how self-maintaining horses live. For more information on that, please refer to the video Understanding the Horse--From the Horse's Perspective and the manual Maintaining a Natural Horse. And, should founder occur, it's best to use treatments that don't interfere with hoof function and thus cause future lameness problems. For more information on hoof function, please refer to the video Understanding the Hoof--From the Horse's Perspective.
