How Equine Microbiome Work

Horses evolved to extract a remarkable amount of nutrients out of relatively poor-quality feed. In the wild, they walk around all day, eating for the majority of a day’s 24 hours. Here’s how the system works.

◆ First, the food passes through the mouth and gets mixed (chewed) with a lot of water and enzymes in the saliva; enzymes help speed up the chemical reactions that occur when food is digested.

◆ Next, the food goes into a tub (aka the stomach): a fairly small tub, actually, given the size of the horse. In the stomach, the food gets mixed with more enzymes and acid, and proteins in the feed start to break down. From the stomach, the feed gets released into a long tube.

◆ The small intestine of the horse is long. Really long. Seventy feet long. But the food moves through quickly, biologically speaking. It travels about a foot per minute and can get back to the hindgut in as little as 45 minutes, depending on how much and what kind of food. In the small intestine, carbohydrates, fat, and protein get digested (by more enzymes and absorbed.

◆ The horse’s hindgut is where the things that make the horse’s digestive system so unique happen. The hindgut (cecum, large colon, small colon and rectum) isn’t nearly as long as the small intestine, but it can handle a lot more feed.

In the hindgut, the horse has countless numbers of microbes (bacteria, protists, fungi, even viruses) that help break down the stems and woody parts of the horse’s forage. The microbes do the important work of fermentation, which in addition to producing fatty acids, amino acids, and B vitamins for the horse, also make the horse gassy.

It’s in the hindgut that a great deal of water is absorbed, as well.

The Equine Microbiome

The microbiome breaks down food to release energy—but that’s not all. It also protects the horse against “bad” bacteria; is involved in the horse’s immune system, helping keep the animal from getting sick; and even produces many of the vitamins that the horse needs.
It’s an area of current research because understanding the equine microbiome is critically important for understanding the horse’s health, as well as for understanding what we can and cannot do for the horse.

Before you can effectively try to modify the equine microbiome, it’s important to know what’s in it. Using genetic sequencing of bacteria (instead of trying to grow them), scientists are finding out that the horse’s GI tract has many more kinds of bacteria in it that was initially thought, especially those that live without oxygen (anaerobic bacteria).

As it turns out, the microbiome of most horses is actually quite similar. The microbiome of a Quarter Horse in Texas is about the same as the microbiome of a warmblood in Connecticut. For the vast majority of horses in different seasons, on different diets, and in different locations, there seems to be something of a normal range for the bacteria in the horse’s GI tract.

What Alters the Microbiome?

Certain things can rather predictably alter the equine microbiome. For example:
Nutrition: When horses eat large amounts of grain in their diet, their microbiome changes. Veterinarians have long known that large amounts of grain are associated with all sorts of diseases, including laminitis and colic.

One reason is that large amounts of grain change the bacterial population. As long as a horse gets enough forage (fiber from hay or pasture), giving him some grain doesn’t seem to affect the microbiome. It’s at high concentrate levels—such as are fed to racehorses—that the microbiome changes.

While changes in the horse’s microbiome probably also changes some of the physiologic processes of the horse, it’s too early to say if this change directly causes disease. In many other species, it’s been shown that the microbiome is slightly sensitive to things like diet, season, and acute changes in diet; however, these changes aren’t necessarily associated with disease. This is food for thought and future research.

Antibiotic use: Antibiotics kill bacteria. The gut is full of bacteria. Antibiotics can affect the microbiome, and different antibiotics affect different bugs. That’s easy to understand. Perhaps less easy to understand is why antibiotic-induced diarrhea isn’t more of a routine problem in horses.

Disease: When there’s intestinal disease, e.g., colitis, there are also big changes in the microbiome. It’s been shown in at least one study that the microbiome of horses that colic is different from the microbiome of horses that don’t colic, but it’s too early to say that a change in the microbiome will always cause a horse to colic. It’s another area for future research.

To make things even more complicated, all disease-caused changes to the equine microbiome are not created equal. For example, horses with diarrhea caused by Salmonella bacteria appear to have a different microbiome from horses with diarrhea caused by antibiotics.
If that’s the case, it may be possible to develop a microbiome index to see if it’s possible to tell what might have caused the changes. Such efforts are underway.

The Question of Probiotics

People with GI disease, such as Crohn’s Disease, inflammatory bowel disease, and the like, have different microbiomes than healthy people. However, it’s not yet known if that’s the case in horses.

Although “supporting,” “improving,” or “protecting” microbiome is a goal of equine digestive products everywhere, giving such products—for example, pre- or probiotics—doesn’t magically make a horse’s GI tract safe, secure, and efficient.

While the relatively few bacteria that are in equine probiotic products may provide some benefit, they do not “normalize” the equine GI tract. There are a few other things that are known.

◆ The horse’s stomach is, among other things, a vat of acid. Acid is one of the worst things you can run into if you’re a bacterium, and there’s a lot of question about how much, if any, bacteria can survive the stomach if you squirt some in a horse’s mouth.

◆ Probiotics are not drugs, and they aren’t regulated as drugs. This is to say that you really have very little idea what you’re giving when you’re giving a horse a probiotic.

◆ There’s also the problem of content. Various products may not contain the bacteria that are said to be in them, the bacteria in the product may not be alive, and the cell count (the colony forming units, or CFU) may not be as advertised.

◆ There’s the question of dose. In humans, products may have as many as 900 billion CFUs, and humans are about 10 percent of the size of most horses. While equine products vary, the doses are usually much, much smaller. Even if a product were to be effective, a dose of 2 billion CFU (or even 25 billion) isn’t like to go very far in a horse.

When it comes to the equine microbiome, scientists don’t yet know enough about what’s normal to go about making any strong recommendations or having any firm conclusions about what to do when things are abnormal. Happily, horses seem to do pretty well without any help, even though there’s certainly a lot more to learn.

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Without question, one of the more respiratory diseases of the horse is infection with a bacterium called Streptococcus equi, more commonly known as “strangles.”

But what is strangles, and how can it be prevented? And if your horse gets strangles, is he going to be OK?

What is Strangles?

Strangles is a messy disease caused by a contagious bacterium. It is one of the most commonly diagnosed contagious diseases of the horse, and it occurs throughout the world. It was first reported as early as 1251. To put that in perspective, that’s about the same time that the Mongols were rapidly expanding their empire.

Although most horses recover from strangles without a problem, the disease can make some horses extremely sick; it even kills a few (although the same can be said for every other infectious disease). The fact that infected horses look like they feel so bad—combined with the name—probably makes horse owners panic about strangles more than just about any other equine infectious disease.

Horses infected with strangles typically have a fever (temperature above 101.0 degrees Fahrenheit), go off their feed, and develop a snotty nose (just like many respiratory infections). What distinguishes strangles from other respiratory diseases is that affected horses quickly develop swollen, sore lymph nodes, especially in the space between the jaw bones. These lymph nodes eventually abscess, open up, and discharge a lot of pus (which, quite frankly, is disgusting). Most infected horses recover. In most cases, antibiotics are not required.

Complications

While most horses recover from strangles uneventfully, complications do occur in others. In particular, the infection can spread to other lymph nodes, including those inside the horse’s body.

Infection of internal lymph nodes is colorfully known as “bastard” strangles. When the internal abscesses rupture, it can pose a serious problem.

In order for recovery to occur, affected horses must be given antibiotics for several weeks. Additional complications include purpura hemorrhagica, a serious immune system reaction, muscle soreness (immune-medicated myositis), and a lack of milk production in infected, lactating mares.

Three Truisms About Strangles

There are three basic truisms about strangles:

◆ Nobody wants their horse to get strangles.
◆ Everyone gets worried when their horse gets strangles.
◆ Everyone gets worried that their horse is going to get strangles when someone else’s horse gets strangles.

Given the above, there are many opinions about what to do about strangles. Some interventions are effective, others probably don’t help, and others may hurt.

OPINION NO. 1: Vaccination is a good way to prevent strangles. (Doesn’t seem to be.)

Without question, vaccination is one of the most important things that has ever been done to help improve the health of most species on the planet. Many vaccinations have been tried for strangles. Unfortunately, none of them have been shown to work.

There are currently two types of strangles vaccines. One is given in the muscle; one is squirted up the horse’s nose. Both have reported complications (to be fair, so do most vaccines). However, there’s no consensus on the effectiveness of the available strangles vaccines. In fact, most countries in the world don’t vaccinate against strangles, and there’s no evidence that the disease rate is any different in those countries.

When deciding about whether to use a strangles vaccine on a horse, one has to weigh the perceived benefit of “doing something” against the possibility of causing harm. While there’s little evidence that the vaccines are of much benefit in preventing strangles, there’s some evidence that they can cause harm, not only in terms of reactions, but, in the case of the intranasal vaccine, conversion of the bacteria used to the disease itself. Follow the advice of your veterinarian.

OPINION NO. 2: If your horse—or a group of horses—is near a horse with strangles, vaccinate them immediately. (Probably not necessary.)

When faced with a disease outbreak, it’s certainly tempting to vaccinate all horses who could conceivably be exposed to the disease. That may not be a good strategy, however. Because not only is there little evidence that the vaccines are effective, vaccinating—particularly in the face of disease—runs the risk of immune system reactions, especially an immune reaction called purpura hemorrhagica.

If a horse is exposed to the strangles bacteria, his immune system will start to react; that’s a big part of how your horse gets rid of the disease. However, overstimulating the immune system can have severe consequences. In fact, there is significantly increased risk of purpura reactions in horses that have been exposed to strangles and then vaccinated.

OPINION NO. 3: Horses develop natural immunity after they’ve been infected. (In a word, yes.)

Approximately 75 percent of horses who have recovered from a strangles infection will remain immune to another infection for five years or longer (the immunity is not lifelong).

OPINION NO. 4: The infection spreads through the air. (Nope.)

Strangles is spread by direct contact: contact with things such as snotty noses, contaminated halters, shared water troughs, dirty human hands, or mucous-covered shirt sleeves.

Nasal shedding usually begins two to three days after fever begins, and horses may be infectious for at least six weeks after their noses have dried up.

More troublesome are those uncommon horses with persistent guttural pouch infections. These carrier horses can shed the bacterium for years and be a source of outbreaks.

The infection isn’t easily spread by particles that get blown into the air (which is how viral diseases like influenza or herpesvirus spread). As such, stall walls, or isolation, serve as fairly effective barriers to the transmission of the disease.

Otherwise stated, if your horse is in one barn, and a horse that’s sick with strangles is in another barn, your horse will probably be OK. Just don’t walk your horse over to rub noses with the sick one. S. equi can remain viable in water for four to six weeks. However, contrary to “common knowledge,” it does not persist in manure or on the ground.

OPINION NO. 5: Antibiotics cause horses with strangles to get “bastard” strangles. (Again, nope.)

A stated concern has been that antibiotics are the worst thing possible for horses with strangles. In particular, there’s a myth that giving antibiotics to a horse with strangles will make the bacteria run and hide—that is, it will make the affected horse more likely to get internal abscesses (“bastard” strangles).

There’s simply no evidence that this is the case. It’s certainly true that antibiotics should be used judiciously when treating horses with strangles, but that’s the case in any situation where antibiotic treatment is being considered.

In fact, in selected cases, antibiotics are useful in strangles treatment. For example, it has been shown that penicillin given early—prior to the development of abscesses, when horses only have a fever—can prevent the full-blown disease. Of course, antibiotics should only be used after first consulting with your veterinarian.

Prevention

While not as severe a disease as many people fear, strangles can be a real problem for herds of horses that aren’t carefully managed, as well as for individual horses that are severely affected.

If your horse has strangles or is at a facility where strangles has been diagnosed, a careful and comprehensive approach to getting rid of the problem, directed by your veterinarian, is important. Such an approach may include:

◆ Isolating and treating sick horses.
◆ Quarantining incoming horses before introducing them to a herd, checking them to see if they are carriers and treating them if they are.
◆ Using good hygiene measures, such as cleaning stalls and waterers, to prevent transmission. Although rare, infections in humans have been reported. When dealing with infected horses, handlers should avoid contact with infectious material, especially around the nose and mouth.
◆ Limiting exposure of healthy horses to sick horses.
◆ Recognizing horses with fevers early and giving them antibiotics before abscesses start to form.

Strangles can be a serious disease in an individual horse, but control of the spread of the disease requires careful, thoughtful management of the entire herd and premises. Prevention can’t be achieved merely by vaccinating horses and giving antibiotics indiscriminately. If you know the facts, you can more effectively tackle the disease head-on.

This article about strangles in horses appeared in the April 2020 issue of Horse Illustrated magazine. Click here to subscribe!

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You or someone you know has probably had a horse come up lame for a reason that’s not immediately obvious. He doesn’t have an obvious wound or a swelling that you can see from across the barn aisle, yet is limping nonetheless. It’s perplexing. Horses are a significant investment of time, money and emotion. You’d really like to know what’s wrong. However, you most likely also have a few questions rolling around in your mind about diagnosing a mystery lameness:

◆ Assuming that you don’t want to provide a blank check, what should you do?
◆ Even if you do write a blank check, how likely is it that you will come up with an answer?
◆ Even if you do come up with an answer, will the answer make any difference in your treatment?

The standard for lameness diagnosis and treatment has been to try to find out exactly what the problem is and then try to “fix” it. If you know the exact cause, you can often come up with a treatment plan that is most likely to result in a horse that is lameness-free (and as soon as possible).

But it’s more than that. Knowing “exactly” what the problem is a powerful and important psychological motivator. Knowing what’s going on with a horse gives a sense of control to an emotionally unsettling situation. The horse has a problem, but with knowledge, veterinarians and owners become empowered to do something.

Trying to define the precise reason for a horse’s lameness is a good goal, but
unfortunately, it’s one that’s not always possible. In spite of careful observations and extensive diagnostic work, and even with the advances in diagnostics and therapeutics that have occurred over the past several decades— ultrasound, MRI, CT scan, scintigraphy, et cetera—there are still lame horses that defy an accurate diagnosis.

There are also those that in spite of a precise diagnosis don’t respond well to treatment. What’s an owner to do? We’ll break down a lameness exam and go step-by-step through the procedure and the costs.

Cost LeveL 1: The Physical Exam

To diagnose a mystery lameness, the horse is initially examined from a distance for things like how he holds his leg(s), abnormal bumps or swellings, his attitude, and other hints that might indicate the source of the problem.

Next, the horse is usually examined up close. The leg is poked, bent, hoof-tested, prodded, moved, et cetera, in a variety of ways to see if there’s a response that might indicate pain (with emphasis on the “might”).

Many times—probably more than 50 percent of the time—careful examination is all that’s needed in order to determine the source of the lameness, or at least to give a good idea if there’s a serious problem.

A good physical exam is important, but it can be misleading, too. Sometimes, a horse with an obvious lameness does not respond in any meaningful way to all of the poking, prodding, and manipulation. On the other hand, some horses respond to just about any sort of poking, prodding, and manipulation, thereby rendering such well-intentioned annoyance (to the horse) somewhat meaningless.

For example, if a horse reacts to having the base of his neck pinched, it’s possible that could indicate some neck or shoulder soreness. It could also mean that the horse doesn’t like to have his neck pinched.

Such things are important to keep in mind when diagnosing a mystery lameness, especially when you’re confronted with unique diagnoses based on a response to a horse being poked at some special “point.” One of the difficulties in interpreting the response of horses to various stimuli is that they’re subjective. If your horse is doing fine and someone tells you that there’s a problem based on responses to such stimuli, don’t be too quick to think that there’s a hidden problem.

The Horse in Motion

After the physical exam, the horse is usually examined in motion. In the field, this can be done in hand, at the longe (on a line or free), or under saddle, and after various stress tests (e.g., flexion tests).

Here, too, there can be a lot of room for error. For example, riders can alter the way horses move, and flexion tests are notorious for being non-specific—that is, they don’t pinpoint lameness—as well as causing a lot of false positives. Some horses may trot “off” after flexion because they don’t like having their legs bent up, not because of any real problem.

Even with the limitations, watching the horse move is an integral part of a lameness exam.

Cost LeveL 2: Local Anesthetic Blocks

It’s often a good idea to confirm that the reactions noted during the physical examination are actually associated with the lameness. Alternatively, if the physical examination is relatively non-productive, that is, no sore spots or swellings are found, but the horse keeps limping anyway, local anesthetic “blocks” are usually the next step.

The idea with nerve blocks is disarmingly simple. The horse is limping because something hurts. You make the part that hurts go numb and, voilà, the horse stops limping.

Nerve blocks are a very important part of a lameness exam. However, over the past couple of decades, veterinarians have become aware of the fact that nerve blocks are not as precise as was previously assumed. That may mean a veterinarian may be “blocking” more anatomical sites than he or she thought, and that the lameness has not really been specifically pinpointed to a particular location. On the other hand, some spots are so big, or so difficult to reach, that they can be very difficult to block.

Regardless, after anesthetic blocks, in most horses you can eventually make the horse stop limping, and you can begin to focus on a specific area as the source of the lameness problem.

Cost LeveL 3 (and Higher): Additional Diagnostic Tests

Unfortunately, even if you can make a horse lameness-free with an anesthetic block, you still may not know exactly what’s wrong. As such, there may be a desire to look deeper, that is, to go on with additional diagnostic tests.

That’s when veterinarians may suggest diagnostic tools such as MRI, ultrasound, radiographs (X-ray), scintigraphy, or CT scan, to get even more information. Of course, all of this diagnostic curiosity, while perhaps ideal from a diagnostic standpoint, can get really expensive.

For example, MRI, which can give a very detailed picture about what’s going on inside the area examined, can easily run $2,000 or more.

Diagnostic Costs vs. Benefits

When evaluating lameness, horse owners can rapidly run into a conflict between wanting to find out exactly what a horse’s problem is and wanting to be able to buy groceries next week. It may be great to know exactly what’s causing a
horse to limp, but at what cost?

Furthermore—and this is an important question to ask—even if you decide to pay for the test, is the knowledge gained likely to change the treatment?

Resetting the Bar

In my opinion, while knowing exactly what anatomical area is causing a horse’s lameness is a great goal, in some circumstances, it might be good for horse owners to think about resetting the diagnostic bar.

There is such a thing as “overdiagnosis,” that is, information that doesn’t really help in selecting a treatment or improving an outcome. Perhaps a more realistic and less expensive standard—especially when it comes to difficult “mystery” lameness cases—might be to try to find out if the horse’s problem is likely to be serious, and then go from there.

This article about diagnosing a mystery lameness originally appeared in the October 2019 issue of Horse Illustrated magazine. Click here to subscribe!

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Tendon and ligament injuries are among the most common and concerning injuries that affect athletic horses of all breeds and disciplines. Injuries such as a bowed tendon or strained suspensory ligament carry fear, sadness, and frustration for horse owners who may be concerned that such injuries mean the end of their horse’s riding career.

What is a Tendon or Ligament?

Structurally, tendons are ligaments are similar to ropes. That is, they’re one large fibrous structure made up of many individual fibers. They are critical in supporting and/or transmitting forces throughout the horse’s musculoskeletal system. There are dozens of tendons and ligaments in the horse’s body, although the ones that are of most common concern are in the horse’s lower limbs.

Tendons connect muscles to bones. When muscles contract (which is the only thing that muscles can do), the force of contraction is transmitted to the bones via the tendons.

Ligaments, on the other hand, connect bone to bone. Ligaments are like shipping tape used to hold two boxes together (with the boxes being bones in this analogy). Ligament functions are more passive than those of tendons, but certainly no less important.

How do Tendon and Ligament Injuries Occur?

In general, injuries to a horse’s tendons or ligaments occur in one of two ways: suddenly, or over time. Sudden injuries are perhaps easier to understand, and occur after a single incident or accident where the forces placed on the horse’s limb exceed the strength of the tissue.

An awkward step, unexpected blow, or misplaced limb can result in immediate and obvious damage to a tendon or ligament, usually resulting in swelling, pain and lameness. However, sudden injuries appear to be the exception rather than the rule.

Most tendon and ligament injuries occur over time from chronic stress and fatigue to the tissues. Stress and fatigue is what causes a paper clip to break when it is bent back and forth repeatedly. A single bend causes no apparent damage or weakness; repeated bending in the same place causes the clip to weaken and snap.

Repeated stress to tendons and ligaments without adequate time for rest and recovery, such as can occur when horses are overtrained, causes strain and injury to the tendon or ligament fibers. While the damage can be occasionally be catastrophic, in most cases only a relatively small percentage of the fibers are damaged.

How are Tendon and Ligament Injuries Diagnosed?

It’s usually not difficult to see the signs of injuries to tendons and ligaments. They are often accompanied by signs of inflammation that have been recognized since the days of the Romans.

• Swelling: Swelling occurs due to bleeding and fluid movement into tissues. The swelling of lower-limb tendon injuries gives rise to the common term “bowed” tendon: the contour of the injured tendon bows out from the swelling. In other cases the swelling is not so obvious, such as with an injury to a tendon or ligament inside the horse’s hoof.
• Pain: Injured tendons and ligaments are painful. Pain causes gait abnormalities (limping) that are most commonly seen at the trot. Swollen, injured areas may also be painful to the touch, or flexion of the limb may compress injured areas and lead to pain when a horse is trotted off after the limb is flexed for a short period of time.
• Heat: Although perhaps harder to detect, inflamed and injured tendons and ligaments are demonstrably warmer than surrounding tissues. While investigators have tried to take advantage of this fact by using instruments that detect heat as diagnostic tools, so far, these tools have not been widely employed by the veterinary community, as their accuracy and reliability is suspect.
• Redness: The fourth classic sign of inflammation is rarely diagnostic in the horse due to thick, pigmented skin and the hair coat.

In the 1980s, ultrasound was introduced to help diagnose tendon and ligament injuries. Ultrasound has revolutionized care of these injuries. Ultrasound allows for earlier diagnosis, as well as the ability to monitor injuries through the recovery period.

What Treatments for Tendon and Ligament Injuries Work Best?

In humans, the gold standard for immediate treatment of tendon and ligament injuries is known as RICE therapy:

• Rest: Horses with tendon and ligament injuries should be rested in the immediate post-injury period.
• Ice: Ice constricts blood vessels and slows down the process of inflammation. Ice can be applied for periods of 30 minutes and should be applied several times a day. There are no benefits gained from icing injured tendons and ligaments for more than three days.
• Compression: Bandaging helps keep the swelling down, which may help prevent further disruption to the injured tissues. There are also compression devices that can be applied to the limbs; these devices can help cool the limb.
• Elevation: In humans, the “E” in rice stands for elevation of the limb. Elevation keeps fluid from collecting in the injured area. Obviously, this isn’t an option for horses.

Medication to control pain and inflammation, such as non-steroidal anti-inflammatory drugs, are also a cornerstone of post-injury therapy. The goal of such medications is not necessarily to make the horse pain-free; rather, it is to help control the inflammatory response. The use of such medications should be short-term and as prescribed by a veterinarian.

After the acute injury has been treated, successful rehabilitation usually requires several months of controlled, increasing exercise, depending on the severity of the injury. Exercise increases both in time and intensity as the injured limb heals.

Monitoring of the healing process by serial ultrasound examinations is often recommended to make sure that the rehabilitation process is occurring without making the injury worse.

Do You Need to Use Expensive Treatments for the Best Results?

Tendon and ligament injuries can be frustrating in horses because they don’t heal with normal tendon and ligament tissue. The tissue that replaces the normal type 1 collagen is a different type, called type 3 collagen, which is neither as strong nor as elastic.
Recovery can take a long time. For decades, people have looked for ways to get tendon and ligament injuries to heal more quickly and with a better quality of repair.

There are few parts of the horse that have received more therapeutic attention than the tendons and ligaments. The past several decades have seen the rise and fall of therapies such as tendon splitting and stabbing, laser therapy, various light devices, magnetic boots, pulsating magnetic field therapy, Bapten (an injectable therapy thought to help direct the healing process), Adequan, bone marrow injections, and many others.

More recently, therapies optimistically and perhaps disingenuously referred to as “regenerative” have entered the fray, leading to treatments with therapies such as platelet rich plasma or any number of stem cell regimens (which themselves are now under increasing scrutiny).

To date, the only thing that can be said about such therapies is that, in spite of their enthusiastic, optimistic, earnest promotion and application, none have been shown to increase the quality of repair or decrease the time required for recovery injury compared to the tried-and-true methods of rest and rehabilitation. And all of them increase the cost of care.

How Long Does Rehabilitation Take?

As with any injury, the prognosis for recovery and the time needed for successful rehabilitation of tendon and ligament injuries is directly related to how severe the injury is. The more damage that is sustained, the more difficult it is for the horse to recover.

The prognosis for recovery is also dependent on what is expected of the horse after injury; the prognosis for a horse to go back to pleasure or trail riding after an injury is far better than that for a racehorse that will be running at full speed. In fact, racehorses with tendon or ligament injuries may go on to find happy and useful homes post-racing as pleasure and trail horses.

Can a Horse Ever Be Considered Completely Recovered?

Although tendon and ligament injuries do not heal with normal tendon and ligament tissue, repair tissue is usually strong enough for horses to fully return to athletic performance. Of course, there are many individual exceptions:

• Horses that are expected to work to the limits of their capacity, such as racehorses, have a much more difficult time recovering from injuries to the digital flexor tendons than do other horses.
• Jumping horses that have injured a hind limb suspensory ligament may have difficulty staying sound because they will be asked to jump again on a ligament that is weaker than normal.
• Horses with poor conformation or genetic conditions such as degenerative suspensory ligament disease (DSLD) may have trouble recovering because of inherent structural problems.

Understandably, tendon and ligament injuries are one of the injuries of most concern to horse owners. Unfortunately, none of the many therapeutic options that have been presented over the past several decades have resulted in measurable improvements in the quality or speed of healing.

Fortunately, and although there are notable exceptions, most horses that suffer from such injuries can go on to lead productive athletic lives after a slow and careful recovery.

This article originally appeared in the September 2018 issue of Horse Illustrated magazine. Click here to subscribe!

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