NEW ARTICLE !
The Science and Simplicity of treating common equine lameness.
Patty Stiller CNBF, CLS
copyright 2008
Introduction
I began my career as a farrier back in 1982. In farrier school I was taught the traditionally accepted principles of horse shoeing, most of which had been in use for several hundred years. These principles had been”updated” over time, as new studies and ideas about the mechanics of the equine foot were made available.
I used these principles from the time of my graduation from farrier school in the early 1980’s until the mid 1990’s. I did the best I could treating common equine lameness and trying to prevent it. Some lame horses got better, a few never improved much despite ”doing everything possible ”. Conditions such as “navicular syndrome” seemed inevitable in some horses due to conformation, breed or use. The gradual worsening of navicular syndrome in horses was accepted as the usual progression, and deemed inevitable. Farriers never imagined or blamed themselves for causing it. Most chalked it up to poor breeding, conformation or use.
Treating those cases became more and more frustrating, as the shoeing protocols that I had been taught were applied and would offer some relief for a while. Inevitably the lameness would gradually worsen again, and more radical shoeing would be needed until finally the horse would be deemed untreatable and end up with a neurectomy to cover up the pain, retired, or euthanized.
As well there were those horses who were just never “quite right”. Those who were maybe not obviously lame all the time but a little “off” especially when turning corners . Vets would do diagnostics and X-Rays and never really find an exact cause.
Then something happened in late 1995 that changed my entire outlook on preventing and treating lameness. The event offered me some new insight about the root of many lameness problems.
I was asked by a veterinarian to attend a demonstration and lecture by Gene Ovnicek, who had conducted hoof wear pattern studies in feral horses and was discovering how applying that information might benefit domestic horses. At that time Gene was considered radical in the hoofcare industry because his ideas were challenging some of the traditionally accepted principles about farriery which had been in place for many decades.
The questions that arose from these feral hoof studies opened the door for more research from scientists all over the world about the problems in domestic horses’ hooves. It was just the beginning of a new look at how to better manage hooves.
The advent of high tech research techniques for equines including “MRI”, computerized loading, kinetic and movement studies, as well as computerized joint and tendon stress studies and new techniques in cellular studies began to reveal a bigger picture of how “off track” we were in some areas of our understanding of the domestic equine hoof.
The most encouraging thing is that we now know is that a large portion of foot lameness in horses comes from abnormal stresses placed on various tissues due to internal misalignment of the joints, and improper foot landings. We now know that a large percentage of foot lameness is centered in the connecting structures of the coffin joint and navicular bone, particularly the ligaments, and that by the time lesions are seen on the bone itself these problems have been going on quite some time. The connecting tissues (tendons and ligaments) around the bones are the first to be impacted by abnormal stresses and poor footfall, then the bones eventually takes the brunt of that and suffer deterioration.
Sound horses land flat to slightly heel first, and load the back of the frog at the same time as the heels. The importance of that can not be over emphasized. The frog and other internal support structures help align the bones correctly upon impact. We now know why a horse may land toe first, and how to correct it. Although it is very complicated, it boils down to the fact that most toe first landings originate from poor internal hoof imbalance.
The practice of shoeing to the very end of the flat trimmed toe with a flat shoe unfortunately often leads to these various internal imbalances.
As well the practice of trying to ”grow more heel” on a foot is extremely destructive because it allows the heel to run forward under the foot, which then leads to internal bruising and heel pain. And by allowing the heels to grow too far forward under the foot, the outer foot loses its relationship with the bones inside, setting the ground surface (the footprint) too far forward under the leg. That creates a tremendous amount of stress on everything inside the foot with every step the horse takes. He also can not get his foot off the ground in time with the rest of his body so he has to shorten up his stride and land toe first.
In some domestic horses there is an internal weakness which causes a front to back misalignment of the coffin joint,(“broken back alignment ”) leading to pain in the tissues under and around the navicular bone, and eventually the destructive shortened stride and toe first landing.
Whether from an inherent weak foot or imbalanced shoeing, the scenario may go like this: first a toe first landing, which then leads to damage to various internal tissues, which then leads to pain in the tissues around the navicular bone (“navicular syndrome” ) which then leads to the horse deliberately shortening his stride and landing more toe first, leading to more internal foot pain, and so on until eventually he ends up with a diseased navicular bone.
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We also now know that a lot of lameness in performance horses originates in the coffin joint and the two ligaments on the sides which connect the coffin joint together (the collateral ligaments). Side to side (medial-lateral) imbalance, as well as stress turning corners are major causes. Horses’ foot joints are simply not designed to turn a lot of corners, especially at speed. And we ask out modern horses to turn tight corners all the time.
Newer anatomical studies have shown that the traditional way of trying to balance the foot medial laterally by sighting down the leg can be very misleading. Studies done on the sole have shown that carefully following the sole of the foot is much more accurate to balance the coffin bone to the ground and evenly load the coffin joint.
Then let’s look at the symptoms of a medial laterally imbalanced foot. It may show up first as a vague shortness turning one direction, then reluctance to take that lead, then reluctance to perform at all until finally he begins to show visible limping.
So to summarize the sources of the foot problems, it is heel pain, internal imbalances, stress to the coffin joint and collateral ligaments, and an outer foot that is no longer centered around the bones which cause a cascade effect that eventually can lead to most common foot lameness issues found in today’s horses.
So here lies a question. Is the toe first landing the cause of the lameness or the symptom?
The answer is that it doesn’t matter when treating the horse. Just fix it.
The treatment goals are fairly simple. Fix all the causes.
That comes in five steps. How exactly you apply the steps is individual, but the principles are the same.
1) Properly trim the foot. Get overgrown heels and bars trimmed back to remove the abnormal pressure that causes bruising, and to move the back part of the “footprint” back where it belongs.
2) Properly balance the internal structures from side to side. Follow the sole plane or get X-rays to insure that you have achieved medial lateral balance.
3) Properly center the outer foot around the coffin joint. If the horse is to be left barefoot this means placing the “breakover point”, or the place the foot pivots over the toe in the correct place relative to where the bone is inside by rasping the bottom of the toe to rocker it . There are means to map this placement out without X-rays which are very accurate. ” If shod, this means centering the shoe around the bone the same way.
4) Insure a slight heel first landing. Most horses will go back to a heel first landing as their comfort level increases with the first three steps. Those that can not will need artificial help to achieve that, possibly in the form of artificial frog support materials, wedges, etc at least for a while until they heal. Mature horses with inherently weak internal structures who can not align their own coffin joint bones may always need some help.
5) Insure that there is eased turning, allowing the foot to roll over in any direction, tipping into the ground easier as the horse turns. This can be done in many ways and at the very minimum, if shod it means using a shoe with a rolled edge. In treating lameness from collateral ligament or coffin joint damage this can be enhanced more with many modern hoes designed for this purpose.
Soft tissues such as tendons and ligaments have the ability to heal if not too far damaged. Therefore a lot of “navicular syndrome” and vague coffin joint pain may be curable. However if the destruction has gone on too long, some things may never heal to the extent that the horse will go soundly without his man made help.
The good news is that we can actually cure so much now than ever before by understanding and removing the causes.
Even horses with tissues that are far damaged to totally heal can be kept so much more comfortable in their jobs despite the presence of that damage, who would have been given up on and either retired or destroyed not too many years ago.
And we have only touched the tip of the iceberg in understanding and treatment. There is more to come in the future.
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Challenges in Managing Horses With Metabolic Issues and Laminitis
By Patty Stiller, Farrier copyright 2005
The Complicated Underlying Problems Laminitis is a devastating condition in which the laminae of the hoof become diseased or damaged, and the coffin bone loses its attachment to the outer hoofwall. The shifting of the bone inside the foot as a result of laminitis is called founder. If you have a horse afflicted with this devastating condition, who is not getting better despite good farrier care, you are not alone in your frustration. The problem with treating laminitis is that the laminitis itself is not always the root problem, it is sometimes a result of deeper issues that may be ongoing.
Laminitis can be caused by many things. Twenty or thirty years ago , most laminitis cases were thought to be due to fairly identifiable causes. Common triggers were things such as fat horses on too much spring grass, or getting into the grain bin and gorging one meal , or a retained placenta in a foaling mare creating toxins in the blood. At times it is caused by some other disease process that creates toxins that affect the laminae. In very old horses, laminitis is a frequent result Cushings syndrome, a pituitary problem thought to be caused by a tumor and characterized by classic signs such as an extremely long hair coat. Although all of those same things still cause founder, in the last couple of decades it has become more apparent that the vast majority of horses with laminitis or founder are afflicted with more complicated and sometimes vague metabolic issues. And these problems are showing up in much younger horses. Breed type and bloodlines seem to have some influence as well.(1,2)
Recently veterinarians are diagnosing more of these horses with metabolic issues being termed “Insulin Resistance” (IR), or “Pre Cushings Syndrome ” or “Peripheral Cushings”, or Equine Metabolic Syndrome” (EMS). (2,3) For ease of discussion I will use the term EMS. EMS horses have a characteristic “look” about them. You may notice things like a cresty neck, even though they may not be overweight, puffiness about the eyes, “lumpy” fat deposits around the tail head and behind the withers, and later, a loss of overall body condition, a sort of “sagging” look. As well ,they may be susceptible to infections because of a lowered immune system. Sinus and tooth infections are fairly common. It appears that EMS involves abnormalities or imbalances in one or more blood levels of insulin ,or cortisol, or glucose, certain minerals and may actually be separate conditions that are somehow related, or all parts of one bigger condition . Though there is research ongoing concerning this issue, and plenty of theories, no one has presented definite answers yet.
Whatever the actual scenario, most affected horses have become unable to process carbohydrates correctly, sometimes resulting in high blood glucose and insulin levels, (just like type 2 diabetic humans). (1,2,3,4) With blood testing, some are found to have elevated fasting glucose levels, elevated insulin levels, or elevated cortisol levels, or a cortisol level that fails to fluxuate properly throughout the day. In a normal horse the cortisol is supposed to be lower at night. Therefore a “cortisol rhythm” test may be helpful along with other tests. (2,4) The horses thyroid levels often test low as well, but some veterinarians believe that the low thyroid level is probably a secondary result of other imbalances, not the primary issue. Veterinarians disagree on the best or most accurate blood tests to administer , but in my own farrier practice the horses with the most successful recoveries have been those who received thorough blood work , treatment based on those test results, and follow up blood work to monitor changes. I will give directions at the end of this article to resources where you can gather more detailed information helpful to the horse owner and veterinarian get more information.
The biggest challenge for the farrier is trying to manage the hooves of these affected horses while the metabolic problems are still ongoing. As long as there are active metabolic imbalances, the laminitis will still be active. In that case, no matter what the farrier does for the hooves mechanically, the horse may still be in pain due to recurring inflammation and instability inside the feet, and the feet can not heal. Therefore it is up to the owner and veterinarian to find a way to control the metabolic problems.
The horses who have the best results are consistently those who got the most intensive nursing and medical and dietary management from their owners. This is easier said than done. Managing the metabolic issues can be extremely complicated. It seems that one imbalance may be driving another, which drives another, and so on. So you may have several “vicious cycles” going on all at the same time. At any rate, the end result is chronic and sometimes unrelenting laminitis. Though there is much disagreement among scientists as to exactly what IS the root cause that begins all this, the secret in getting it under control seems to be to break the cycle somewhere. Here are just a few of the difficult scenarios that may be going on. Certainly horses that have been obese for a long time are at the most risk. “Easy keeper“ breeds are especially susceptible . (1) Fat cells release an inflammatory chemical, TNFa . TNFa is speculated to cause “stress induced” insulin resistance and increased cortisol levels. (5) Therefore it is dangerous to allow those breeds to develop a fat cresty neck just because the breed type is commonly seen that way . A cresty neck may NOT be normal in most breeds. We could be just so used to seeing it that it may appear the ‘norm’. Most susceptible breeds include Pasos, Morgans, Arabians, Ponies, Mustangs etc. (1).
Most of the researchers and veterinarians agree that glucose intolerance is at least a large part of the problem. IR horses are similar to human type 2 diabetics. They have insulin, but the cells have become resistant to it, so it no longer moves the carbohydrates in the blood into the cell for use as food. The blood levels of insulin get high as the body continues to try to process the carbohydrates, and the carbohydrates float around in the bloodstream unable to feed the cells. The laminae may then starve (7)There may be gut toxins at work too, especially when the horse has been kept on long term “Bute” (an anti inflamatory drug) for the pain. (7,8)
Cortisol is another player, probably the most important one in this complicated scenario. Cortisol is naturally released into the bloodstream in response to stress, pain or inflammation. Excess cortisol in the horses system causes a process called “catabolism”, in which the cortisol scavenges protein out of connective tissues to gather “raw materials” for use elsewhere in the body.(9) In the long term, catabolism weakens ALL the connective tissues in the body . For instance, dogs with Cushings syndrome sometimes are first presented to the vet with a ruptured Cruciate ligament. This connective tissue weakening can cause not only tearing of the laminae in the hoof, but also chronic pain all over the horse. That may be why horses with ‘full blown’ Cushing syndrome get sore joints . It is also the probable reason that the farrier struggles so much trying to find comfort for these horses.
Plain grass hay has long been the recommended diet for foundered horses, and is still probably the best choice as the base diet and is recommended by most veterinarians. But beware, not all grass hay is the same! Recent research (www.safergrass.org) has shown that grass hay can vary widely in carbohydrate content. Some hay can be as high as over 25 percent carbohydrates! It depends on variety, geography, weather, harvesting times and so on. And a lot of carbohydrates in a meal will drive your horse’s insulin response up as the body attempts to process it. STRICT limitation of carbohydrates is necessary. (6) Katy Watts, forage researcher at www.safergrass.org therefore strongly recommends that your hay be tested for carbohydrates. This is not a normal hay test that your feed dealer would have done. The website has references where to get that done. In the absence of testing, she has also done research that shows how soaking the hay can extract some of the carbohydrates. Please visit that site for more information.
As well, lowering carbohydrates means no more grain, molasses, sweet feeds ,sugar, apples or carrots. And no cheating. But your horse DOES needs good overall nutrition and some good carbohydrates to feed his cells and repair tissue. Plenty of protein, a little fat, and balanced minerals and vitamins. However it is not prudent to just toss in more of anything without first knowing what you are starting with. This means knowing the nutrition content of your hay .(3) Because of the growing demand for low starch but nutritionally complete diets , several feed companies are now manufacturing low starch, forage based, supplemented pelleted feeds. Two examples are LMF Stage 1 and LMF complete, (LMF is the only one that tests the hay that goes into the pellets) and Triple Crown ‘Low Starch’. There are now other brands too so you will have to check your local dealers. Do NOT just trust that a feed is low carb simply because it is not a sticky molasses filled “sweet” feed. Read the labels and look for ‘red flag’ ingredients such as grain and molasses. Senior feeds can be particularly dangerous if they contain grain or molasses.
Most practitioners also agree that dietary supplementation is also useful. Many horses in my hoofcare practice have improved with careful supplementation to balance their minerals, and removal of carbohydrates from the diet. Magnesium is an important mineral . Magnesium regulates many hormonal functions. Though the veterinary community is mixed on its feelings about the helpfulness of mineral supplementation, there are consistent anecdotal reports of supplemental magnesium helping these horses more rapidly lose the cresty neck, lose the excess weight, and regulate the thyroid levels. Chromium Picolinate has been shown in Human type 2 diabetes to help process carbohydrates , so it too is being used to help treat these horses. There are many feed supplement companies that have these supplements available by mail order. One example is Uckele Animal Health. (www.uckele.com) . Many natural supplement companies are making supplements available specifically for Insulin Resistant horses. Uckele has one called "Glycocemic EQ” which contains chelated magnesium, chromium, as well as other ingredients for hoof growth, all ready mixed. Zinc, copper and manganese are important to help grow hoof and connective tissue. As well, Manganese deficiency may also be a factor in the development of insulin resistance.(11)
Sulfur, (found in the joint supplement MSN) is an important structural component as well as an anti oxidant. Some veterinarians also say that laminitis is an example of ”free radical damage out of control” (8) and therefore employ anti-oxidants with good results. Anti oxidants include but are not limited to CoQ10 enzymes, MSM, and Vitamin C. Many horse owners as well as their veterinarians are using homeopathic and herbal medications.(3,8,10) Each has a very specific and sometimes strong action so please consult a trained veterinarian herbalist before you just toss any to your horse. . These include (but are not limited to) Slippery Elm bark, Hawthorne berry, and Chaste berry. In the cases where diet and feed supplements do not get the metabolism under control.
There are medications your vet may want to try. In the past, veterinarians used Cyproheptadine, but more common now (and reportedly more effective) is Pergolide mesylate (Permax). Most veterinarians reserve it for the most stubborn cases but some practitioners use it on all their cases or as a diagnostic tool. (1) As a diagnostic, the reasoning is “If the horse gets better, he probably has Cushings and therefore needs the drug.” The major considerations to using either of these this drugs are the both may cause or exacerbate liver impairment over time,(12) and Pergolide is relatively expensive. Also, most veterinarians say once a horse gets better on it, he must stay on it. That may be debatable though, because of anecdotal reports of its successful use seasonally or just when as the horses have laminitic relapses. (12), and personal anecdotal reports) It all boils down to the fact that the veterinarian and horse owner must really dig deep to try to stabilize the horses problems. If you don’t get to the root of the problem, the horses chances of recovery are slim and the all farrier work in the world will not help.
Once the metabolism issues are corrected, many of these horses go well barefoot or with fairly simple therapeutic shoeing. If the metabolism is out of control though, nothing will help. Some resources I strongly recommend are as follows: 1) Yahoo.com EquineCushings discussion group. Go to Yahoo.com, click on “Groups” and join the EquineCushings group. It is free When you get there, click on “files” in the left side of that homepage. Read the “START HERE” file first to get yourself oriented. Then, go back into “files” and scroll down to the “JOHNSON ON METABOLIC SYNDROME” file. It is a wonderful dissertation by Dr. Phillip J. Johnson from University of Missouri, and is a Must Read” , in my opinion. After that just read all the files you can. There are lots of scientific papers posted there about supplements, feeding, hoofcare and so on.
For endocrine testing. BET labs in Lexington Kentucky will do consultations with your vet if they want to help understanding some of the tests and exactly how to administer and interpret them. BET labs is found at www.betlabs.com. The phone numbers in KY are (859) 273-3036, fax (859) 273-0178 Dr Eleanor Kellon, at the Yahoo group also does consultations.
For finding out more about general hoofcare, including laminitis, go to the The Farrier and Hoofcare resource Center, at www.horseshoes.com. The Discussion Forum has two bulletin boards devoted to laminitis, one for farriers and one for horse owners. As well, that site has Dr “Tookie” Myers as their consulting veterinarian and he also does individual consultations.
Bibliography: 1) Laminitis! Hope for refractory Laminitis, Matt and Susan Frederick 2) Phillip J. Johnson, Professor of Equine Internal medicine, Veterinary medical teaching Hospital, University of Missouri. 3) Eleanor Kellon DVM, Yahoo Equine Cushings discussion group 4) BET endocrinology laboratory, Lexington Ky. www.betlabs.com 5) Dr. Barry Fitzgerald, University of KY , referenced in www.horseproducts.stablemade.com 6) Katy Watts, www.safergrass.org 7) Dr.Chris Pollitt, University of Queensland, Au. 8) Dr.Madelyne Ward DVM,, Dr. Joyce Harman DVM MRCVS “Laminitis Treatment, A natural Perspective”, Hoofcare and Lameness Magazine 9) “Is Cortisol leading You Down the catabolic Pathway? Rehan Jalali, @ThinkMuscle .com 10) Yahoo Groups, EquineCushings @www.yahoo.com 11) Complete Book of Minerals For Health , J.I.Rodale and Staff, 1974 12) Equine Cushings Disease, Robert A Eustace FRCVS, abstracted from the scrutineered Veterinary Journal In practice (1991) Vol 13, No 4, July P 147-148