Mission of the Animal Health Foundation -Don Walsh

..... Laminitis-Founder Syndrome Mission of the Animal Health FoundationTo find the cause and way to prevent laminitis-founder complex in horses. The foundation donates funds to major researchers in the field of laminitis. AHF also offers information to help horse owners prevent their horses from becoming victims of the painful, crippling disease. AHF LinksAustralian Equine Laminitis Research Unit Hoofcare & Lameness American Association of Equine Practitioners Rocky Mountain Research and Consulting www AHF Web site Donors receive a special edition print of Secretariat, who was humanely destroyed to release him from suffering of Laminitis. Help free the horse of this diseaseLaminitis causes the breakdown of the internal supporting the structures (laminae) between the external hoof wall and the coffin bone inside the hoof. The laminae deteriorate when excess activation of enzymes known as Matrix Metalloproteinases (MMP's) cause the attachment of the laminar cells to break loose from their basement membrane. This results in the destruction of the normal blood supply to the laminae and causes severe pain to the horse. Founder is the painful, crippling result of Laminitis in which the coffin bone within the foot "rotates" downward putting pressure on the sole of the foot, sometimes even puncturing it.Causes of Laminitis/FounderCarbohydrate overload - over-eating of grain Consuming too much fast growing, lush grass in the spring and fall Retaining placenta infection that follows failure to expel the afterbirth within a few hours of foaling Mechanical damage to the feet from excessive concussion on hard surfaces Metabolic stress such as becoming overheated Ingestion of Black Walnut shavings Hormone related changes due to Cushings disease Drug induced Laminitis from using corticosteroids Any serious illness may lead to laminitis Signs of Laminitis/FounderSigns of this disease may vary greatly from quite subtle to very obvious.There may be shifting of weight from foot to foot. A slight stiffness of gait may be detected. The horse will not want to move, and often assumes the "founder stance", with all four feet forward of the normal position, head low and back arched. The horse may lie down and not want to get up. Sweating, shallow breathing and a fever are typical. The feet may be warm to the touch and usually a pulse can be detected on the back pastern, below the ankle. From one to all four feet may be involved; most commonly the two front feet are affected. Unfortunately, when symptoms of Laminitis/Founder Syndrome are first noticed, the disease process may have already caused irreversible damage, therefore it is important to call your veterinarian immediately. The first 24 hours after onset may be critical to the outcome.Treatment Guidelines These guidelines are meant to serve as an overview to the general principles in treating and preventing Laminitis. Each case is different and must be treated individually. It is not the purpose to advocate a treatment for all cases, as this is impossible. It should be left to the attending veterinarian and farrier to make the final decision on how to manage each individual case.Remove the cause Make every attempt to determine what caused the onset of laminitis and prevent further exposure. The cause is often difficult to determine, but since we do not understand the ‘trigger mechanism’ of the disease, the cause must be eliminated, even if the horse is recovering. Some of the possible causes of laminitis are: diet and grain overload, allergic reaction of any type, excess concussion to the feet, reaction to bedding, bad water supply, post-parturient retained placenta, aftermath of colic, diarrhea, severe myositis and excess stress such as hauling and prolonged exposure to high temperatures.Control the infection Many horses develop infections due to the death of tissue in the feet. If infection is present (this is not always easy to determine) the feet must be opened to establish drainage of the infection. The feet must be soaked in a warm disinfectant solution (Lysol, betadine or epsom salts) daily. They should be packed with a mild antibacterial salve and kept bandaged until the soles are healed. If fecal material is allowed to continue to get into the feet, the infection will persist.Support the feet Some supportive device should be used to stabilize the bone in the foot if there has been enough damage to the laminae to cause any degree of separation. This includes ‘lily pads’, styrofoam pads, or corrective shoes such as heart bar shoes, which support the coffin bone to prevent further separation of the laminae. Only a skilled farrier should put on these special devices with the assistance of radiographs and the presence of the attending veterinarian. If these are not applied correctly they can cause considerable damage. Care should be taken in selecting a farrier. Again, not all cases of laminitis need these shoes, only the more severe cases. These shoes have been used in many chronic horses with success to prevent continual breakdown of the laminae in the chronic foundered foot.DrugsThe use of excessive and prolonged drug administration may confuse the status of the horse and possibly be detrimental to the case. In the early stages, the use of non-steroidal anti-inflammatory drugs (i.e., bute, banamine) seems very useful, but beyond this point they only make the horse feel better. They are not really involved in the healing process, and may be detrimental in some cases. Therefore, we advocate using minimal amounts of drugs so that the real status of the feet may be evaluated and not be masked by these drugs. This is often difficult for horse owners to do since they don’t like to see the horse in discomfort. However, this may be necessary in order to evaluate the progress of the case and to tell if the feet are continuing to refounder. Often the best thing is for the horse to lay down and relieve the pressure on the damaged laminae.ExerciseThe effect of exercise may vary in each case. If a horse has severe damage to his feet, exercise (especially early in the disease) may make the horse worse. As time goes on, the amount of exercise may be increased. A rule of thumb to use may be that as you start to exercise the horse and he seems to improve after a short amount of walking, then it is probably helping. However, if he seems to get worse or is very reluctant to move, you should discontinue the exercise and allow more healing to occur before you start to try again. Generally, as horses are recovering you can increase the time you walk them. If you overdo the exercise, the horse will usually be sore the next day so you will know you did too much. Use a surface that is free of rocks and hard material that would put excess pressure on the soles.DietDiet is probably one of the most important areas in the treatment of laminitis as well as the one that we seem to understand the least. It is probably safe to say you should reduce grain intake and increase roughage in the diet. We recommend that corn and alfalfa hay be removed from the diet, as they often seem to be incriminated as a causative factor. The diet we currently feed consists of 3 parts oats to 1 part bran. The average amount of feed given to a 1,000 pound horse is 3-4 pounds total per day. The diet is fed in conjunction with good quality grass hay. It is beyond the scope of these guidelines to discuss all the extra supplements used for the treatment of laminitis.Chronic Cases Chronic obese-type laminitic horses and ponies require no grain, but can be fed good quality dry grass hay. They should not be allowed on grass pastures, particularly in the spring and fall of the year. Sometimes the use of thyroid supplement seems to reduce the incidence of reoccurrence in these animals. They suffer from a form of metabolic disease associated with being overfed. They require little to live on because their genetic makeup allows them to survive in areas with little available food. Their exposure to excess food causes changes in hormones, which increase the appetite and seem to influence the breakdown of laminae in the feet. Many of these conditions can be reversed after a prolonged reduction in food intake. However, many animals have had so much damage to their feet that cold weather, shoeing and other minor insults to the feet result in painful bouts with the disease. These cases are very difficult to manage.History of laminitis Laminitis FAQ Are certain breeds more prone to get laminitis?What are the known causes of laminitis?My horse has laminitis, what is his/her long-term prognosis?What is the difference between laminitis and founder?What can I do to make my horse more comfortable with her laminitis?What are the best times to allow grazing?What exactly happens inside a horse’s hoof during the onset of laminitis?Is there a correlation between degree of coffin bone rotation and survival?Do weather events trigger laminitis? (hot summers, hard winters, etc.)Is my overweight horse more at risk of developing laminitis?Are some pasture grasses safer than others? Hays? Grains?How many horses suffer from laminitis?What is the first thing I should do if I suspect my horse is coming down with laminitis? Is there anything I can do while I wait for the vet?Is laminitis reversible? Can the coffin bone rotate back to its pre-laminitis position?My horse has recovered from laminitis and is sound. Is he more at risk than other horses for future problems?How important is my farrier and veterinarian in laminitis recovery?Has progress been made in laminitis research?What can I do to help find a cure?Where will my donation go?Are certain breeds more prone to get laminitis?No breed is safe from laminitis. Any horse, from a champion Thoroughbred to a back-yard pony, can get the disease. However all pony breeds, Arabians, Quarter horses, and American Saddlebreds seem to have a higher incidence of laminitis. TopWhat are the known causes of laminitis?Here is a list of several known things that can cause laminitis, several of which we as horse owners can control:Obesity Excess ingestion of grain Excess ingestion of grass Black walnut toxicosis (bedding a horse on black walnut shavings) Exposure to corticosteroid drugs Retained placentas in mares Any gastro-intestinal abnormality within the horse (diarrhea or colic) Laminitis can occur after severe bouts of myacitis, kidney failure, or severe lung disorders. After a horse has run a fever. Top My horse has laminitis, what is his/her long-term prognosis?There is no way to predict the outcome. Every case of laminitis is different. It even varies within the case from foot to foot as to the severity and what the long-term prognosis is. It takes 6 to 8 months to know what kind of recovery the horse is going to make. SMost horses that have a favorable prognosis show marked improvement during that 6 to 8 month period. TopWhat is the difference between laminitis and founder?Laminae are the structures within the hoof that connect the external hoof wall to the internal coffin bone. When the laminae are inflamed, the horse is said to have laminitis. When the bond between the bone and the hoof wall is damaged severely the bone starts to move inside of the hoof capsule, it moves downward or sinks. When that happens, the horse is said to have foundered. Founder is an old nautical term used to describe a sinking ship. TopWhat can I do to make my horse more comfortable with her laminitis? (physically and emotionally)This is a difficult question because the use of drugs to counter the pain of laminitis often encourages the horse to think they have recovered enough to move around. It may be in the horse’s best interest to lie down, and get the weight off the affected feet. So the use of pain medication must be monitored very carefully with restriction of their exercise, because too much movement can be detrimental to the long-term recovery of the horse. It’s important to keep the horse in an area that has a lot of soft bedding, and is large enough to move around a bit. From an emotional point of view, it’s much better if they have another horse that stays with them or in close proximity so that they don’t feel like they’ve lost their association with other animals. Having their best friend with them is a great idea! TopWhat are the best times to allow grazing? (times of day, times of year)What we know about grass laminitis is that there is a sugar called fructans in pasture grasses. Excessive ingestion of fructans is thought to cause laminitis in some horses. The level of fructans is excessively high levels in the spring and fall of the year, when we have cold nights and warm days with bright sunshine. In early spring, when we have very cold nights, level of fructans are probably high in the plants all day long because they haven’t been utilized during the night. This is due to the plants being in a very low metabolic state due to the cold temperatures. In the latter part of spring, when we start to have warmer nights, the safest time of day to allow grazing would be in the afternoon and the early morning hours. In mid-summer after the plants have stopped flowering, in this stage of its growth the plant is the safest for the horse to eat. In the fall when the colder nights return and the days are still warm and sunny, even after a light frost the fructan levels can be very high. The best times of year to allow total grazing are in the depth of winter or in mid-summer. Exact times vary by region. TopWhat exactly happens inside a horse’s hoof during the onset of laminitis?When the trigger factor (for which we are still searching) arrives in the horse’s foot, it triggers an event which activates the protease enzyme located within the basement membrane. When these protease enzymes are activated for too long a time, the basement membrane starts to slip away from the dermis. The destruction of the basement membrane by these protease enzymes results in a stretching of the laminae (this resembles a glove coming off of a finger). The result is the bone loses the support in the hoof capsule by the laminae. This lack of support causes the bone to sink into the hoof capsule. After this occurs the horse has severe laminitis, and when this tearing is happening and the coffin bone is sinking there are great amounts of micro hemorrhaging and inflammatory response in the foot.Over the next 6 to 8 months the foot is in the process of trying to rebuild itself. It is not very well understood why this rebuilding process is more successful in some horses than others. We try to keep the horse from moving around very much when it is in the acute stage of the disease. Then gradually as the horse starts to heal and improve, we encourage them to move around. We think it ultimately helps the process of re-growing the hoof to occur much more normally if they have exercise. TopIs there a correlation between degree of coffin bone rotation and survival?For a number of years the degree of coffin bone rotation was used as a prognostic indicator as to whether the horse would be usable again. In the past few years this has proven to be an invalid method of evaluating how bad laminitis will be in a horse, and we no longer recommend using this as a prognostic tool. Many horses that have made recoveries and appear to lead fairly normal lives would have been put to sleep using the old guidelines. TopDo weather events trigger laminitis? (hot summers, hard winters, etc.)Other than the fact that weather influences fructans in the grass in the spring and fall of the year and the associated impact on grass laminitis, there is no evidence that any weather event can trigger laminitis. We do see some correlation with horses that have chronic laminitis, some of these horses have Cushings disease or metabolic syndrome. Many of these horses have reoccurrences or an exacerbation of laminitis about a week following extremely hot weather. Similarly in the winter after very severe weather for a week or two, a week or so afterward we see an outbreak of a number of cases.It is not known whether this is stress-related or has to do with thermal problems in these horses’ feet. TopIs my overweight horse more at risk of developing laminitis?Yes. In study after study the most important factor in trying to prevent horses from getting laminitis is to make sure they do not become obese, either as babies or as adults. There is evidence that obese-related laminitis is the most common form of the disease that we presently see. We know that if these horses exercise and diet that they can become normal again not have abnormal blood work or have any reoccurring bouts of laminitis. So this is a preventable form of the disease if we can get the weight off of these horses. Please see our risk assessment for more information: Risk Assessment. TopEstimate a horses' weight (75K PDF) Are some pasture grasses safer than others? Hays? Grains?What we know about pasture grass is that the lower the level of non-structural carbohydrates the safer the grass. The warm-season or C4 (i.e., native grasses, prairie grasses and Bermuda grass grasses) generally have a lower level of non-structural carbohydrates. The cool-season or C3 grasses, which includes the most common types of grass hay (i.e., timothy, orchard grass, brome, fescue, clover), have higher levels of non-structural carbohydrates.We usually recommend not feeding alfalfa hay. And we recommend having the non-structural carbohydrate level in your hay evaluated. It should be less than 10% if being fed to a horse that has previously had laminitis.All grains have the potential, if over-fed, to cause a starch overload in the hind gut. So you need to be careful not to over-feed grains. TopHow many horses suffer from laminitis?In the USDA study conducted in 1998, 2.1% of the population of horses studied had had or were suffering from laminitis in the prior twelve months. Of that population of horses studied, 4.8% had to be put to sleep.Those don’t seem like large numbers until you do the math. There are an estimated 8 million horses in the US. If 2.1% of them suffered from laminitis, that would be 168,000 cases in a year. And 8,064 of those horses would have to be put to sleep. TopWhat is the first thing I should do if I suspect my horse is coming down with laminitis? Is there anything I can do while I wait for the vet?The first thing to do is call your vet and try to get him/her to see the horse as soon as possible. The next thing to do is try to put the horse’s feet in ice water. Try to ice all four feet and legs up to the mid-cannon bone area with very cold or ice water. Do this as much as possible for at least 24 to 48 hours. This slows the activation of the protease enzymes in the feet and it also reduces the blood flow carrying the laminitis trigger factor to the foot.For information regarding activation of the protease enzyme, see the question regarding what happens inside the horse’s foot during the onset of laminitis. TopIs laminitis reversible? Can the coffin bone rotate back to its pre-laminitis position?The horse will never be as sound as he would have been had he not had laminitis. However, laminitis is treatable and to some extent the effects of the disease can be reversed. Although many of the horses can have improvement after re-growing their foot, they will always show the effects of having had laminitis. TopMy horse has recovered from laminitis and is sound. Is he more at risk than other horses for future problems?Yes. All horses that have had laminitis are in the highest risk category to redevelop the disease. It is very important to keep this horse from becoming obese, and to control his diet and grazing habits. TopHow important is my farrier and veterinarian in laminitis recovery?These are the professional people who have the ability to evaluate the healing process inside of the horse, and also the condition of each of the four feet. It is essential that the horse owner, the farrier, and the veterinarian work together with good communication. Communication must be open between all three of these people for the benefit of the horse. It is imperative to the success of treating these cases. TopHas progress been made in laminitis research?Over the last 20 years much progress has been made in identifying the actual way that laminitis takes place. We have moved from understanding that it is now a disease that is caused by the over-activation of an enzyme system instead of a circulatory failure as we once thought. We have also traced the mechanism by which this occurs down to a molecular level. We know within which cells it occurs, and we are now looking at the molecular structure of the hemidesmosomes. These are the objects that start to come apart which allow the basement membranes to loosen and pull away. TopWhat can I do to help find a cure?Support laminitis research. The only way that we will ever be able to prevent laminitis is to understand completely how it is caused, what the trigger factor is, and the ways in which we can control that trigger factor. Without good laminitis research we will not be able to prevent the disease. TopWhere will my donation go?One hundred percent of all public donations to the Animal Health Foundation go directly to fund laminitis research. All expenses incurred by the foundation are paid by the Board of Directors. More information on the researchers we support... ©2006 Animal Health Foundation