In this article we look at the difference between ligament injuries and tendon injuries in horses and investigate more commonly found ligament and tendon injuries found in the equine community such as a suspensory ligament injury, a bowed tendon injury and Deep Digital Flexor Tendon injuries.
What is the difference between a tendon and a ligament?
Both ligaments and tendons in horses are made up of fibrous connective tissues. Often categorised as the same things they do in fact differ greatly.
Ligaments help stabilise the joint whereas tendons are located at each end of a muscle attaching the muscle to the bone.
Tendons in horses
Tendons are elastic type structures which attach the muscles to the bones of the horse. Most tendons in horses are short in length, but the longer tendons which run down the limbs can be vulnerable to strains and damage, particularly in active work or exercise.
The most common tendon injury in a horse is found in either of the two flexor tendons.
The flexor tendons consist of the DDFT, the deep digital flexor tendon, and the SDFT, the superficial digital flexor tendon. Both of these can be found running down the back of the horses legs from the hock (knee joint) downwards.
Tendons are encased by a fluid filled sheath, with the most commonly known being the digital sheath close to the fetlock.
Along with the digital flexor tendons there are several short annular tendons which help the horses ligaments stay in place in areas of high movement such as the horses joints and hips.
Horses tendons (and ligaments) contain minimal amounts of blood in comparison to muscles.
Ligaments in horses
Horses ligaments are elastic soft tissues which attach their bones to their joints and provide support to the joint.
The main purpose of a horses ligament is to maintain their bones in alignment and to support and stabilise the horses joints, as our ligaments do for us. Some joints have one ligament supporting them on both sides so there are many ligaments within a horses anatomy.
Collateral ligaments are found in the coffin, fetlock and hock joints. Palmar annular ligaments are only found in the fetlock. Whilst the accessory (check) ligament is next to the deep flexor tendon and the meniscal and cruciate ligaments support the stifle.
Common injuries to horses tendons
Equine tendon injuries occur more often in exercising horses due to the nature of the injuries often relating to movement.
Horses are at greater risk of sustaining tendon injuries if overweight or unfit although strenuous activity can create risk for any horse. Movements where the horse may over stretch such as jumping, moving on uneven ground or turning tightly can lead to tendon strains. Galloping on uneven surfaces or flying around a barrel creates significant movement within the joint and which can naturally lead to tendon injuries. It is there for easy to recognise how common tendon injuries are experienced in horses as many of us push our horses to their full capacity.
The severity of the injury can vary which in turn dictates the required treatment.
If a horse receives a knock or bump which does not break the skin then sometimes bruising of the tendon can be caused, in severe cases the tendon may even rupture or tear. Tendons can develop a small hole which runs through the fibres and creating minor soreness to a localised area.
In more severe cases where a wound or laceration damages the tendon immediate attention is required. If the sheath surrounding the tendons is involved then this can lead to potentially life threatening infections.
SDFT and DDFT, deep digital flexor tendons are the most common injuries found in horses tendons. Located in the fetlock region of a horse and providing stability and lubrication to the fetlock these tendons are subjected to a lot of movement and stress and as such can experience strains or trauma.
Tendonitis in horses is a degenerative condition which directly relates to the horse tendons and is thought to develop through overworking the tendon in exercise.
Spotting equine lameness early is a vital part of managing your horses; often establishing whether your horse is showing signs of lameness through a tendon injury can be complicated. Any users adopt the approach of ‘prevention is as important as cure’ and as such provide an ongoing plan to support their horses tendons.
Common injuries to horses ligaments
One of the most commonly reported ligament conditions found in a horse is Suspensory Desmitis but as with fans your horse can experience issues with many of its ligaments, often dependant on the exercise. Jumping horses will put stress on ligaments different to those who compete in barrel racing or dressage, as an example.
The most commonly reported cause of a ligament injury to horses is 'trauma through exercise'.
The more active the horse, the more at risk they are from injuring a ligament.
Horses in active work such as sports horses competing in barrel racing, polo, dressage, eventing, showjumping are at much higher risk to ligament strains than a pet horse turned out at home.
Although ligament injuries are widely found it is with great interest how few ligament injuries are seen in the sports horse community at the highest level; often associated to the horse being trained to stretch the ligament on an ongoing basis. As an example, a professional showjumping horse will stretch its ligaments and tendons to almost impossible levels and show no signs of pain or discomfort. As with someone beginning to work out a home, aches and pain and strains are more frequent as the body begins to adjust to the new activities it is being subjected to - as this is the same for horses.
Retiring sport horses however have higher-risk with issues with their ligaments (and tendons) and as such many are treated accordingly throughout their career and into their retirement.
The most widely diagnosed ligament injuries in horses are suspensory ligament injuries, annular ligament injuries and collateral ligament injuries.
Suspensory Ligament Injuries in horses
The suspensory ligament in a horse is there to support the fetlock and prevent it from hyperextending within exercise. The ligament itself starts behind the cannon bone in both the front and back legs and runs down the back of the cannon bone before branching into two and attaching to the sesamoid bones at the back of the fetlock. Although the ligament is strong it is only slightly elastic.
Due to the location and purpose of the suspensory ligaments, unfortunately injuries to the suspensory ligaments are common and particularly in sports horses or animals leading an active lifestyle.
The suspensory ligament goes through excessive stress when a horse is travelling at speed and when landing from a jump. In essence a suspensory ligament strain is through over stretching the ligament (hyperextending) which creates trauma within the ligament itself.
Although a suspensory ligament injury can occur through a single movement many suspensory ligament issues are actually caused through repetitive strain and over a period of time. More serious suspensory ligament injuries will often show a complete tear (or hole) in the ruptured fibres of the ligament.
Treating suspensory ligament injuries in horses can be a long process. A period of immobilisation (box rest and recuperation) will be required, sometimes for as log as 12 months, and in some cases painkillers and anti-inflammatories will be administered. Surgical intervention may be required if the injury to the ligament is severe. High hind suspensory ligament injuries are notoriously difficult to recover from without exacerbating the injury - because of this many owners now look to diagnosis tools to establish how the ligament has healed prior to returning to light exercise. Thermal imaging is relatively low cost technique now used within the equine community.
Annular Ligament injuries in horses
The annular ligament, similarly to the suspensory ligament, is located at the back of the fetlock and is found within the tendon sheath of the horse. When the ligament is injured and begins to become inflamed or swollen the the annular ligament will begin to constrict the tendon sheath. This puts additional pressure on the surrounding tendons and can lead to various levels of pain and lameness.
Damage to the palmar or plantar annular ligament (PAL), created through either direct or indirect trauma can lead to primary desmitis. Secondary desmitis is created through septic tenosynovitis and non infectious tenosynovitis.
Bowed Tendon injuries in horses
A ‘bowed tendon injury’ in a horse is when swelling occurs in the superficial or deep digital flexor tendon. This swelling causes the appearance of the leg to look ‘bowed’, hence the terminology. The bow in the horses leg can appear between the knee joint and the pastern joint of the horse.
The horse will show signs of lameness and often walk with their toes tipped-up.
Bowed tendons occur through chronic and repetitive stress on the tendons or in some cases as a result of the tendon being injured. Regular issues with bowed tendons can result in the horse being diagnosed with tendonitis.
A horse with a bowed tendon requires immediate medical intervention as further health complications can occur if the horse is left untreated.
How to detect a tendon injury in a horse
When a horse has a tendon injury this will often result in swelling and inflammation. The leg will often increase in temperature as the fibre damage creates heat. This can be detected by feeling the opposite limb and establishing the difference. It is rare for minor tendons injuries to create lameness but recognising any early sign of an injury will aid a reduction in the horses several recovery time by emphasising the need to recuperate.
Severe tendon injuries can be extremely painful to a horse and require immediate medical advice. Serious cases will lead to the horse being significantly lame.
If you believe any injury has occurred then a clinical examination will be required. The vet will establish the extent of the damage often requiring the use of technologies such as ultrasound scans to ensure an accurate diagnosis.
How to detect a tendon injury in a horse
As with tendon injuries, diagnosis of a ligament injury in a horse is first recognised by the presence of heat and/or swelling in the localised area. In some cases the horse will be sore to touch and be show clear signs of pain. The horses gait and overall mobility level may well reduce.
In the majority of cases where a ligament issue is diagnosed an ultrasound will be required to ascertain the extent of the injury. In many cases a full examination will be required by a medical professional to ascertain the level of lameness and the most appropriate treatment moving forward.
MRI scans and X-Rays may be required and thermal imaging is also widely used to diagnose the initial injury and throughout the recovery process.
In severe cases where the horse is in significant pain and natural recuperation is not enough nerve blocks may be issued until an accurate diagnosis is established.
Treating tendon injuries in horses
Treatment options with horse tendon injuries vary according to the severity of the injury.
There are no guaranteed treatments which ensure a return to soundness. Some injuries can led to permanent scar tissue which make the tendons less elastic and thus impact the performance and overall mobility of the horse.
Previous damaged tendons are more prone to injury than healthy tendons.
Commonly a period of roughly two weeks box rest would be recommended but some injuries can require up to 12 months of rest and recuperation.
In the recovery stage the horse will be recommended treatments that do not increase the temperature of the legs such as bandaging to immobilise the limb and ice applications to help reduce the heat within the tendon. It is there for important that owners do not use traditional magnetic products on tendon or ligament injuries as these have shown to increase a thermal reaction within the horses body. Advanced magnetism by StreamZ is gathering momentum in the market to support horses recovery after injury as their unique approach does not create heat and thus can be used on horses recovering from a tendon injury or condition.
Most horses will be prescribed anti-inflammatory medications to aid the reduction of the inflammation within the tendon, and NSAID painkillers (such as Bute) which can provide the horse with short term pain relief. Some horses, particularly competing horses cannot use NSAID painkillers though and there remains adequate about the long term use of NSAID medications. As such, holistic and alternative therapies are becoming more popular and widely adopted within the equine world.
The most severe cases of injuries can often lead to surgical corrections or even Neurectomy (nerve blocking) techniques.
Physical therapy and rehabilitation techniques will also be required in the majority of cases.
Treating ligament injuries in horses
The initial treatment of ligament injuries in a horse are treated similar to that of a tendon strain or injury. Again, there are no guaranteed treatments which ensure a return to soundness.
Some injuries can lead to permanent scar tissue of the ligament which make them less elastic and thus impact the performance and overall mobility of the horse moving forward. This can mean the end of a professional competing horses career. Previous damaged ligaments are more prone to injury than healthy ones so any horse with a history of ligament damage should be closely monitored.
Commonly a period of roughly two weeks box rest would be recommended. In this time the horse will be recommended treatments that do not increase the temperature of the legs such as bandaging to immobilise the limb and ice applications to help reduce the heat within the ligament. Most horses will be administered anti inflammatory medications to aid the reduction of the swelling and provide the horse with short term pain relief.
In severe cases surgery may be required. Other treatments include stem cell treatment, plasma therapy and shockwave therapy.
Following treatments a slow and controlled rehabilitation period would be required, sometimes as much as 6 to 12 months. The horse needs to increase its fitness levels and overall wellbeing and be completely sound before bring them back into work.
Frequently Asked Questions regarding Tendon or Ligament Injuries in horses
Are tendon/ligament strains more common in sports horses?
As with us, the further horse pushes it the more at risk the horse is to over extending and thus damaging the muscle, tendon or ligament. It is therefor more common to experience torn, damaged or even ruptured tendons/ligaments in horses who have the opportunity to extend themselves in this way. Competing sports horses or younger horses who are naturally more active are more prone to this condition and as with an athlete means the horse will undergo an extensive recovery and rehabilitation process between competing or exercising.
Are tendon and ligament injuries due to the genetic make-up of my horse?
Not as such however the genetic make-up of the horse have significant impact on whether a horse will be more at risk to tendon or ligament issues at some stage. Poor confirmation has shown to lead to greater risk so it is advised to look at the confirmation at the back of the knees, how straight the hind limbs are and whether it has a long back and a short croup.
Can traditional magnetic boots and rugs be used with tendon injuries?
No. If you look at how traditional magnets operate they create a pulsating action from the face of the magnet. This process creates an internal thermal reaction within the horse. When looking to support tendon or ligament recovery avoiding heat is vital and thus traditional pulsating magnets could create further issues. A non invasive complimentary device such as EQU StreamZ and a joint supplement containing Glucosamine or similar is advised, neither of which will increase heat in the tendon or ligament.
Can monitoring technologies such as Magnetic Resonance Imaging (MRI) and Ultrasounds (X-Rays) help diagnose tendon/ligament injuries?
Yes. Advancements in technologies over the past few decades have led to extremely accurate diagnosis of tendon and ligament injuries. Although not cheap they are widely available from most equine professionals. Thermal Imaging is now gathering a reputation for being accurate whilst lower cost than other diagnosis tools, ideal for ongoing investigations.