Understanding Laminitis

The most common sign of the onset of laminitis is lameness. If the horse can be persuaded to walk, it moves with a shortened stride, with each foot quickly placed back on the ground. Standing still, the horse appears to have its "feet nailed to the floor" in the parlance of old-time horsemen. The characteristic stance of a laminitic horse includes hind feet brought forward under its belly to get most of its weight off its front feet, which are stuck out in front of its normal center of gravity. If all four feet are affected and the horse is in severe pain, it might lie down and be reluctant to get up again.

On closer examination, you may find that the horse has a bounding pulse. Always check the pulse before moving the animal, because even in a healthy horse, a few steps can increase the pressure within the blood vessels.

There are cases of severe, acute laminitis in which the pulse is very faint or not detectable at all. Most have warmer than normal feet. But in rare cases, they can be ice cold as well. Therefore, you must use other clinical signs if you have a suspected case of laminitis. The most obvious sign is acute lameness or signs of pain. You most likely have an emergency. Even if the horse ultimately does not have laminitis, its pain requires prompt attention, so call your veterinarian and your farrier. Ask them to come out to see the horse right away. You want to include your farrier because he or she knows your horse's feet better than you do and can be extremely helpful in telling the veterinarian what changes might be noticeable.

The quicker you get help for your horse, the greater the chances that the horse will recover. Help means treating the acute inflammatory stage as well as the inciting cause, and mechanically reversing the forces at play that are working to destroy the vital, sensitive areas inside the foot. It's vitally important for your vet and farrier to work together at this point to treat this potentially devastating disease.

Therapy that's initiated the moment the horse shows the slightest sign of laminitis increases the window of response time so critical to the horse's recovery.

Establish the grade of lameness
It helps to be able to tell your vet how lame your horse is. There are several published grading systems referring to lameness in general. However, it's helpful to differentiate the degree of lameness in the context of possible laminitis.

  • Grade 1) Walks sound, trots lame, turns sore. You can readily pick up any of the four feet.
  • Grade 2) Walks sore, turns on hind feet, reluctant to trot. Reluctant to have feet picked up.
  • Grade 3) Refusing to trot. Has to be persuaded to walk. Very reluctant to have feet picked up.
  • Grade 4) Stands with feet rooted to the ground. Reluctant to move even with strong persuasion. Refuses to have feet picked up. Very painful facial expression. If lying down, very difficult to make them get up.

Industry wide statistics are not very encouraging as far as prognosis is concerned and many veterinarians worldwide consider complicated laminitis akin to a death sentence. A majority of laminitic cases recover using various means of treatment -- some even without treatment -- and seem to suffer no ill consequences. However, 20% to 30% of the across-the-board cases will have a very devastating insult, resulting in catastrophic damage to the laminae, costing either careers or lives.

A lackadaisical approach to this syndrome works well if you have a very mild insult. But unfortunately it is impossible to differentiate between mild and complicated cases at the onset of the syndrome. If you treat the complicated case as you would a mild case, you essentially have destroyed your chances of saving the career or even the life of the horse.

In my experience, I have had good success rates with complicated cases using a disciplined, methodical approach.

Laminitis can strike one or all feet
Many people think laminitis is caused only by overeating and that it always involves the two front feet. Therefore, it is unlikely for them to suspect that a multitude of other problems can cause laminitis. While overeating grain or grass can cause laminitis, commonly resulting in lameness in the front two feet, there are numerous other causes that are just as prevalent and every conceivable combination of feet -- from one to four -- can be involved. Cases involving a single foot, called unilateral laminitis, are quite common. Laminitis involving both hind feet with no front feet involvement is rare. When it occurs, damage can range from mild to severe.

The degree of damage varies considerably from case to case and is influenced by the severity of the insult at the onset. Due to the complexity of the syndrome and response to therapy, I have found it impossible to describe a single set of signs, or a preferred treatment protocol yielding a good response.

Therefore, to help you understand laminitis, I will make references to specific signs that are representative of the basic categories of this syndrome. Each example will be described as to its characteristics, signs, symptoms, history, response to treatment, and prognosis for recovery. 

To talk specifically about laminitis, you will need a point of reference. Trying to lump all of the possible variables and all cases into the single, broad category of laminitis becomes very confusing to owners, veterinarians, and farriers and leaves us without a meaningful way to initiate a precise treatment regime for a specific case. After 25 years of extensive experience, I have found this blanket approach to be the main reason the prognosis for complicated cases has always been so poor.

To make your in-depth study of laminitis more productive, consider the following "typical" laminitis scenarios.

Example # 1 (typical acute)
In this example, we start with a fit and healthy horse which has been in rigorous training, either for racing or some other type of athletic competition. The horse is handled and observed on a daily basis, so that the changes would be noticed almost immediately.

It began showing a marked reluctance to move in the stall or to walk out of the stall. When the horse was encouraged to move forward, its head went up, its hind legs traveled under the abdomen, and its front legs moved forward in a very stiff fashion.

The horse's eyes told a painful story. Its respiration and heart rate increased. The horse seemed "nailed to the floor, exhibiting signs of distress when you tried to pick up either front foot (one is usually more painful). The feet seemed warmer than normal, but since the feet of some laminitis cases remain quite cool to the touch, this was not a reliable sign.

When you checked the digital pulse it seemed quite strong. To feel for the pulse, reach down and lightly touch the vessels where they course over the back corner of the fetlock. There the digital vein, artery, and nerve can be found under the skin. It is the artery that has the bounding pulse, if it exists.

In a healthy horse, the normal resting pulse can be very difficult to detect and you must have a very light touch in order to feel it. Regularly checking the pulse of your horse helps you better understand the range of normal. In a laminitic horse, the pressure with every pulse beat seems to thump hard against your thumb and forefinger. The heart rate might be normal or elevated, but it's the increased pressure within the vessel that we're actually feeling.

It is thought by some horsemen as well as some professionals that a mild case of laminitis doesn't warrant immediate treatment as they have had good prior experience treating this syndrome with various conservative methods. Unfortunately, in the early stages of the syndrome, there is no way of determining the course of events that lies ahead for your horse. If you decide to risk playing the odds and do not immediately treat the laminitis syndrome aggressively and there has been a very significant insult to the laminae, you have lost a large majority of the window of time where prompt treatment can make the biggest difference.

Treating complicated cases aggressively from the onset does not guarantee you with favorable results as cases with massive lamellar death at the time of onset can be non-responsive to the most aggressive of techniques. On the other hand, using a maximum mechanical and therapeutic treatment regime at the outset offers unlimited options that are not available with a more conservative approach. Treating a horse with great hope of total recovery in this fashion assures you that you're doing everything possible and, barring unforeseen setbacks due to vascular collapse, your end results can be very favorable.

Looking for clues
Early treatment is designed not only to attack the syndrome but to prevent the secondary mechanical destruction. While you wait for your veterinarian and farrier to arrive, review what might have prompted the onset of laminitis. Consider what occurred the previous 48 to 72 hours. Did your horse travel and have a stressful trip? Did it have a high fever or signs of labored breathing? Has it been exposed to conditions that might precipitate pneumonia or some other respiratory disease? Has one or more of its limbs become swollen for apparently no reason? Has the horse recently received an influenza vaccination or any other kind of injection? Has the horse recently been given corticosteroids?

Although treating horses with corticosteroids can have very beneficial effects, I advise caution. A small percentage of horses have developed laminitis within a few hours to a few days following corticosteriod therapy. Many veterinarians believe that there is a direct correlation. Even though the incidence is quite low, I am among many veterinarians who believe there is an inherent risk in such treatments and therefore caution is advised when using corticosteroids.

Note: As far as steroid therapy, we basically have two: (1) corticosteroids (such as Dexamethasone, Depo-Medrol,Vetalog, etc.) have potent anti-inflammatory properties indicated for numerous uses; and (2) anabolic steroids (including Winstrol-V, Equipoise,  and others), which are used to increase appetite, stimulate muscle development, and are hormonal in nature. Anabolic steroids should not be confused with corticosteroids.

Has your horse inadvertently consumed a much larger amount of grain than it normally eats? Many horses require tremendous amounts of grain to maintain peak condition, whereas others might need only a handful. When a horse manages to break into the feed room, it might eat only what it needs while others will gorge until they have consumed all of the grain. If a horse devours too much grain, you have a major problem. Call your veterinarian immediately as swift action cannot only prevent gastritis and subsequent laminitis but it might save the life of your animal.

Other things to consider:
When was your horse last shod? Did your farrier have any problems or comments concerning the feet? Your farrier most likely knows the unique characteristics of your horse's feet much better than you, which is invaluable when assessing the degree of damage. Things the farrier might look for: increased sensitivity around the coronary band; changes in the coronary band itself, such as swelling or discharge or moisture that might indicate serum leakage or a possible abscess; an abnormal ledge formation or an abnormally distinct margin to the hoof wall; increased sensitivity over the sole and toe area detected through use of a hoof tester.

Has the conformation of the sole changed? Is the sole sagging, does it seem to be fuller? Is the sole bruised? The farrier might pull the shoe to better inspect the area under the shoe for hot nails and other shoeing-related problems. His or her findings become invaluable in helping the veterinarian interpret the visual as well as radiographic evidence of a potential problem.

The veterinarian will assess the overall health of the animal in an effort to rule out underlying metabolic problems that could possibly have precipitated the acute signs of pain. It is extremely important to address the seat of the problem if it can be diagnosed.

When nothing out of the ordinary has occurred, consider whether your horse has experienced stress. This could be stress from traveling, any change in routine, or changes in feed or water. Veterinarians have long acknowledged a link between stress and the onset of laminitis.

We are aware of certain disease syndromes that can precipitate laminitis, but it's difficult to relate known causes to a particular case. Owners and trainers are distraught thinking they have done something wrong because they can't pinpoint a precise reason for the horse showing laminitic signs. You don't need to know the reason to try to resolve the problem. It can be a helpful indicator to what lies ahead, but close observation of the horse, radiographs, and response to therapy is more valuable than knowing precisely what caused it.

Example # 2 (Unilateral laminitis)
In this example, the horse has a very serious injury in one leg, which leaves him quite lame for several weeks, regardless of treatment, consequently causing him to bear full weight on the opposing limb throughout the recovery. Treating the original injury in successful fashion is one thing, but protecting the other foot from opposing limb laminitis is quite another. Many cases of acute unilateral lameness develop complicated opposing limb laminitis within six to eight weeks of injury. This problem occurs because the horse shifts its weight to that sound limb to relieve pain and pressure on the injured or sore leg. Constant and chronic weight bearing on one limb severely compromises normal blood flow to the laminae and precipitates local ischemic laminitis.

Anticipating potential laminitis in the supporting foot helps us to become alert to subtle changes in stance, shifting back and forth, increased pulse, and other clinical signs. If you wait until the horse is favoring the good limb and putting full support on the injured leg before employing mechanical aids, the prognosis is severely jeopardized.

Other signs of opposing limb laminitis include a ledge along the coronary band, which is a sharp, protruding edge of the wall. The ledge can be confirmed radiographically. The horse's coffin bone has slipped down into the hoof capsule (we call this a sinker). You also might find serum (yellow fluid) oozing from the coronary band. The sole can be flat or bulging down. Palpating the coronary band daily on high-risk patients will help you notice subtle changes which can save your horse's life.

Another typical sign is for the horse to jerk the good foot up, momentarily, as if it were stinging. It then might develop a consistent shifting leg lameness. The foot is in serious jeopardy.

Horses with weak, thin hoof capsules, toe cracks, and other previous injuries or disease are at a much higher risk of traumatic laminitis than those with strong, durable feet. This is important to recognize and efforts should be made to protect the opposing foot mechanically from the ill effects of prolonged, excessive loading.

Fortunately, many of these catastrophic injuries can be treated successfully in four to six weeks. Unfortunately, that's about the time the good foot crashes with a devastating case of laminitis.

In my experience, light-boned fillies tend to have a higher incidence of traumatic laminitis than do colts and mature horses. It is not unusual to see it within two weeks following an acute injury. A large percentage of traumatic laminitic cases can be prevented with early mechanical aids

Example # 3 (Hind limb laminitis)
Hind limb laminitis might not occur as frequently as front limb, but it does happen and it is as much of an emergency. Being alert to the early signs can improve the prognosis.

Horses suffering from hind limb laminitis stand with their hind legs stretched out behind them. They look as if they want to urinate. They will tread back and forth, but are reluctant to move forward. This type of laminitis is difficult to detect early. In fact, it is often misdiagnosed, or mistaken for other problems such as kidney problems or acute back pain. Sometimes the horses will appear to have signs of a neurological disorder such as you may find with EPM (equine protozoal myeloencephalitis). Being aware that hind limb laminitis does exist should become a valuable part of the tentative diagnosis. It should certainly prompt those emergency calls to the veterinarian and farrier. They will thoroughly check the horse's feet with hoof testers and radiographs.

Example # 4 (Obesity)
It's springtime and the grass is long and lush and you are proud that all your horses look great. But there is a likelihood that they are all quite heavy. When they start consuming spring grass that might contain up to 35% protein, they gain several pounds every day. Suddenly, your favorite horse shows acute signs of laminitis. It's standing with its hind feet pulled under its body and is reluctant to move.

Overweight ponies and horses are at high risk of laminitis because fat storage increases the risk of carbohydrate overload, which can trigger the laminitis. Remember that the perception of what's obese and what's not is viewed differently among various breeders and their breed standards. For example, Quarter Horses shown in halter classes could be considered overweight if judged by other breed standards. Excessive weight complicates laminitis as it increases the stress to the feet and internal structures, jeopardizing the magic balance that is basically designed for a much lighter animal.

Many horsemen think that stallions with cresty necks display more masculinity, and therefore, it is a commonly accepted management practice to allow Thoroughbred stallions to increase in bulk quickly as soon as their racing days have ended. Once they have started into the breeding program, many Thoroughbred stallions carry 200 to 400 pounds more than they did while in training. These horses are always at high risk. We must be careful when distinguishing between muscle mass and fat storage. Excessive weight inhibits maximum healing as it adds insult to injury.

Unfortunately, the mindset that accepts excessively overweight horses as being ideal, healthy, and a sign of good management is a real killer worldwide and is the norm on many of our horse breeding farms. Many times the owner who has a huge laminitic stallion or broodmare says, "I know they're a little heavy, but they're just easy keepers."

Once you have recognized and accepted overweight as a blinking caution light, do something about it. I often hear my clients say they do not want to be mean to their horses. The clients claim they can tell the horses look hungry and want to eat all the time. Obesity has serious consequences for man and beast. Domesticated horses must have a controlled diet.

How do you make sure your horse gets a good balanced diet? There is a lot of very good information on today's market concerning what is right or wrong for a horse to eat. Use a reliable source to help you set your program standard and use logic. The fat horses should get less, the thin horses should get more.

Aged broodmares often become very large and carry tremendous weight due to their lack of activity, especially when they are fed an excessive amount of grain throughout the winter and are turned out in lush pastures in the spring. It is amazing the amount of weight these mares can put on in a matter of days. Being alert to each animal as an individual and attuned to their escalating weight can help you make more enlightened management decisions.

Many broodmares' feet are in deplorable condition for various reasons. For many horse owners and breeders, the fact that these mares are used for breeding purposes only might make them ignore the condition of their feet. The mares develop toe cracks, flat feet, have practically no heels, with poor quality horn, sole bruises, abscesses, and combinations of all the above. Given a set of feet as poor as the ones described above, when these horses develop laminitis there is little natural reserve available to combat the ill effects of laminitis. Therefore, horses with deplorable feet are at very high risk when affected by even the slightest insult.

An overweight mare or stallion with very poor quality feet has little chance of surviving the significant insult of laminitis. The same horse, given a strong, durable hoof capsule, has a better prognosis for recovery.

Other Causes of Lameness
There are causes of bilateral lameness other than laminitis. In some cases, bilateral lameness is often found in horses which have less than optimum foot mass and balance. Their lameness comes from one or more of several problems, including bilateral bruising, bilateral abscessing, and even marginal fractures of P 3. The signs they show for these various problems will be similar to the signs of acute laminitis. Fortunately, these problems can be treated very successfully with the same mechanical approach used for laminitis. Therefore, when in doubt, always treat for laminitis as you won't have a better opportunity than at the onset.

Many brood animals will show radiographic signs of chronic laminitis even if the mares have had no previous history of actually having suffered from laminitis. These radiographic signs can be very misleading when presented with an animal that has bilateral bruising, abscesses, or other problems due to direct trauma.

Every acute foot problem has the potential to be an emergency. Therefore, never ignore the lameness and hope that it will go away. Always treat such problems as veterinary emergencies. Call in your veterinarian and farrier for a consultation right away. Together, they can quickly determine the significance of the problem and establish a course of treatment. 

About the Author

R.F. Redden, DVM

Ric Redden, DVM, is known throughout the horse world as a veteriarian, farrier and educator. He owns and manages the International Equine Podiatry Center in Versailles, Ky, the first exclusively podiatry practice in the horse world. Dr. Redden is one of the world's foremost experts on laminitis and other hoof problems and travels internationally, teaching others his ground-breaking techniques and concepts.

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