PRP for Horse Tendon Injuries

Horse tendon injuries are quite common. Certain breeds of horses are more susceptible to certain types of tendon injuries, than others.  The same is true as it concerns the type of activities a horse engages in. For instance, a race horse will typically suffer different tendon injuries then horses which are ridden for leisure. However, though this is true, there are two tendons which horses tend to injure the most. They are the superficial digital flexor tendon and the deep digital flexor tendon.

 Tendons are made of fibrous bundles that form elongated chords.  They are bundled in groups and help connect muscle and bone. Tendons allow the bone to move whenever the muscle is contracted. Tendons, in large part, are categorized as either extensors or flexors. Extensor tendons allow joints to extend, hence the name. Flexor tendons do just the opposite. They allow tendons to bend inwardly.

The two tendons, mentioned above, superficial digital flexor and deep digital flexor tendons, are the most commonly injured. They are located along the back of horse’s leg.  They are especially prone to injury because they handle much of a horse’s work load during movement.

Horse tendon injuries are categorized based on their severity. A strained, stretched tendon is categorized as a Type 1 lesion. A horse that has this type of injury will experience some inflammation in the tendon. The leg where the injury has occurred may appear larger than normal and the site of injury may feel warm. The horse will likely feel pain. The extent of that pain will depend on how badly the horse is injured.

With a Type I lesion, a horse may or may not have trouble with movement. Sometimes these injuries are hard to detect because the horse doesn’t always exhibit lameness.

A torn tendon is considered more severe and is categorized differently then the aforementioned. If the tear is small, it will likely be categorized as a Type II lesion. Bigger, more severe tears receive a Type III lesion classification. These injuries cause the horse a greater amount of pain. There may also be increased swelling and heat.

A horse with a Type III injury will most often experience lameness. Movement will be difficult. The worst classification of tendon injuries is the Type IV lesion. A horse diagnosed with this injury will exhibit a great deal of heat and lameness. The swelling will be noticeable and the injured leg very painful.

When speaking of tendon injuries a person may refer to it as low, middle or high bow. These “zones” are in reference to the injury’s positioning in relation to the rear side of the cannon bone.

The majority of a horse’s weight is carried in its forelimbs. Because this is true, many of the injuries a horse experiences, are in this area. This is because this part of the body tends to more easily become over worked.

As mentioned above, one of the tendons which is more likely to become injured is the superficial digital flexor tendon. It helps to stabilize the horse’s lower leg as well as the flexion. If a horse injures it, it may or many not experience lameness. Even a very serious superficial digital flexor tendon does not necessarily have to spell the end of a competitive horse’s career.

A more serious tendon injury is one to the deep flexor tendon. This tendon helps to stabilize the horse’s leg when the maximum amount of weight is placed on it. In addition to the aforementioned, during hoof flight this tendon flexes every one of the horse’s lower leg joints. If a horse severely hurts this tendon, they may not be able to compete an longer. The horse’s career could, in fact, be over.


When a horse has an injury to their tendon, it may or may not exhibit lameness. Whether or not it will, in large part, depends on how severe the injury is and where it is located. If the injury has just occurred or is really bad, there may be some heat and inflammation. The leg may also appear larger in size,


In order to diagnose a tendon injury, a veterinarian will palpate the leg. This simply means to feel it. This will allow him or her to determine where the injury is, specifically which ligament is injured. Palpitation is generally the first diagnostic step but not the last. A vet will also typically perform an ultrasound on the injured leg.

Ultrasound is often used to diagnose soft tissue injuries. It allows veterinarians to see exactly where the injury is located, and how bad it is.  In addition to ultrasound, a horse may have a MRI done as well.

Traditional Treatment and Forms of Care

When a horse injures its tendon, it will need to rest. Anti-inflammation medication may be given as well. Cold hosing and icing also helps to reduce inflammation. This is done for the first 2 -6 days after the injury has occurred. A little later, a cataplasm may be placed on the leg and it may be wrapped. This does two things, it helps to provide support and further helps reduce inflammation. Recently, more advanced treatments have begun to be utilized.

PRP Treatment

In addition to rest, ice and anti-inflammation medication, newer, more advanced forms of treatment are being used to treat equine tendon injuries, one or them being PRP. Others include Extracorporeal Show Wave Therapy (ESWT), bone marrow transplant, stem cell therapy, IRAP.

ESWT, a bone marrow transplant, stem cell therapy and IRAP are considered at this point to be experimental but promising. The same is mostly true of PRP therapy.  However, it holds an advantage over the others because it is relatively inexpensive, simple to administer and minimally invasive.  The complications and side effects are minimal as well. For this reason PRP is one of the most oft used, newer forms of treatment for equine soft tissue and bone injuries.

PRP therapy is a very simple but effective procedure. It utilizes a horses own blood to jumpstart the healing process. In recent years, there has been a push to harness a body’s own natural processes to help heal it self. Stem cell research is an example of this. PRP is one of the more promising examples of the body working to heal it self. It has been used with much success by world famous athletes such as Tiger Woods and Alex Rodriguez, to expedite the healing of serious injuries. The success in the human realm has encouraged vets to give it a try in the animal one.

PRP therapy is effective because of the injection of concentrated amounts of growth factors and other proteins found in the blood’s platelets and plasma. Growth factors are what the body uses to heal damaged soft tissue and bone injuries as well as wounds.  Growth factors, in concentrated amounts, can be especially helpful in areas of the body where blood flow is minimal. The less blood that flows through an area, the slower the injury will heal. PRP therapy is noted for its ability to accelerate in healing in both human beings and animals.

When a horse undergoes PRP therapy, a veterinarian will draw their blood and place it in a centrifuge, where it is spun. Spinning separates the blood’s components, which is made up of red blood cells, white blood cells and platelets which are suspended in plasma. The veterinarian will remove the platelets and inject them into the site of the injury. In this case, they would be injected into the injured tendon. Typically 52 mLs of blood is drawn and mixed with 8 mLs of anticoagulants before being injected into the horse. PRP gel can also be used.

Before administering PRP therapy, a veterinarian may sedate the horse lightly so that it feels minimum pain. The surface of the injection site might also be temporarily deadened prior to the injection.

Complications are rare with PRP therapy. This is because the therapy involves the use of a horse’s own body fluids. There is a very small risk that the site of the injection could become infected but that risk is the same whenever a horse receives a shot.

After a horse is treated for a tendon injury with PRP, they will need to rest. This is partly because the therapy but also due to the nature of the injury. Tendon injuries typically require rest and then a modified exercise schedule before eventually returning to normal activities.

PRP therapy, when used for equine tendon injuries, is typically done so in conjunction with other forms of care. It is typically not used in lieu of traditional treatments.  Anti-inflammatory medication continues to be used to treat equine tendon injuries because a decrease in swelling is necessary for the healing process. Ice and eventually heat also help with inflammation.