Osteoarthritis in horses: symptoms, treatment, painkillers and feeding tips.

What is osteoarthritis? 

In osteoarthritis, the cartilage between the joints gradually disappears. The articular cartilage is a thin layer and is located between two meeting bone ends and is an elastic buffer that absorbs shocks - as they occur during any movement. The joint fluid, the so-called synovia, provides the suppleness. It also supplies the cartilage with necessary nutrients. The synovial fluid is distributed through movement, lubricating the joint with the cartilage and supplying it with nutrients such as hyaluronic acid. In osteoarthritis, this process cannot proceed smoothly - "smoothly" being the key word here. If the cartilage is not sufficiently supplied with synovia, for example because the horse does not move enough or the warm-up phase is regularly too short, damage occurs to it, causing it to lose elasticity. The cartilage receives too few nutrients when there is a lack of synovial fluid. The cartilage layer gradually wears away. The result: the joint becomes acutely inflamed, a condition known as arthritis. As a result, the cartilage continues to degrade and, in the worst case, the bones rub directly against each other. This is extremely painful for the horse and it becomes lame. The joint becomes inflamed again and again - chronic joint inflammation is osteoarthritis. Bony deformities develop, which can lead to increasing stiffness of the joint as the joint space narrows. 

What are the causes of osteoarthritis? 

Osteoarthritis is often considered a disease of old age. It is true that old horses very often suffer from osteoarthritis because the joints simply wear out due to many years of stress. But age-related wear and tear is not the only trigger for osteoarthritis, which can therefore also affect young horses. Chronic joint inflammation (= arthrosis) is often preceded by acute joint inflammation (= arthritis). This can be caused by injuries, for example. Tendon damage or bone fractures can also lead to arthritis if the horse overloads one leg due to a painful posture. Incorrect hoof treatment or a congenital malposition of the hooves can also lead to such an incorrect load. All joints, and especially those of the limbs, are also overloaded if the horse is too fat - obesity can not only lead to metabolic diseases or laminitis, but can also cause severe damage to the joints. The risk of this is often underestimated. About every second leisure horse is now considered too fat.
Another trigger for arthritis and subsequent arthrosis is that the horse is loaded too early and too heavily. The horse is not fully grown and closed to growth joints until it is about six years old. If a young horse is lunged and ridden at a very early age, it can develop joint problems at a young age. Lunging on the circle in particular puts a lot of stress on the joints due to the centrifugal forces acting on them. But also intensive jumping or dressage lessons can damage the young, not yet fully developed joints. However, "too little" can be just as fatal: Since the joint fluid only fills up around the cartilage during movement, long periods of standing are also a risk factor. 

What types of osteoarthritis are there? 

Osteoarthritis can affect different areas, basically any joint. An overview of the most common forms. 

Shell:

One speaks of so-called shell when the arthrosis affects the coffin bone, pastern bone or coronet bone, i.e. the toe joints. In this form, there is a bone formation in the mentioned areas. A distinction is made between shell close to the joint, i.e., growths around the joint, and joint shell. In the latter case, the joint itself is overgrown. Shell restricts the mobility of the joints and can be painful for the horse, whereby the joint shell usually causes more severe discomfort than the near-joint shell.
Depending on the position of the shell, one also speaks of high shell (between the pastern bone and the coronet bone) and low shell (between the coronet bone and the coffin bone). 

Spat: 

Spat is understood to be arthrosis of the hocks. Here, too, ossification of the hock joint can be the result. Once the joint has stiffened, however, the horse is often pain-free. 

Hoof Roll Syndrome:

Hoof roll syndrome, or podotrochlose, is often abbreviated to just "hoof roll." However, first of all, the coffin roll refers only to the area in the lower end of the leg and includes the navicular bone, the coffin roll bursa, and the deep flexor tendon. In podotrochlose, acute inflammatory as well as chronic degenerative processes occur. The navicular bone and flexor tendon are affected during the course of the disease. Almost always the front legs are affected, rarely the hind legs. The hoof roll syndrome can be manifested by a clammy gait, pain on turning, frequent stumbling or refusal to jump. 

Cervical Spine Osteoarthritis:

Osteoarthritis often affects, but is not limited to, the limbs. The cervical spine (C-spine) can also be affected, mostly in the posterior region between the fourth and seventh cervical vertebrae. Affected horses often have trouble bending or eating. In some circumstances, osteoarthritis in the cervical spine can also lead to lameness in the forehand. In severe cases, it can even lead to ataxia, i.e. an uncoordinated gait. 

What are the symptoms of osteoarthritis? 

Various signs can indicate osteoarthritis in the horse: 

• "Running in" - If the horse runs clammy or even lame at the beginning of a riding session, but after a short time runs in and then moves much better, this is a typical sign of osteoarthritis.
• Lameness
• Swollen joints
• Difficulty getting up and lying down
• Frequent stumbling
• Gall on the joints 
• Disinclination to move
• More severe lameness in cold, damp weather. Metabolic processes are slower in cold weather. Also, the synovium is more viscous. 

Diagnosis of osteoarthritis

If arthritis is suspected, a veterinarian should be consulted. The veterinarian will first have the horse walk and trot on various surfaces and test the joints for mobility. Systematic anesthesia or conduction anesthesia is also frequently used. In this case, specific areas in the horse's leg are anesthetized one after the other, followed by a lameness analysis after each section. 

In this way, the pain can be precisely localized. Various imaging procedures then provide certainty about a possible joint disease: X-ray, ultrasound, computer tomography, but also MRI and diagnostic arthroscopy (joint endoscopy) are used if necessary. For arthroscopy, the horse must be placed under general anesthesia. Such an operation is therefore only possible in a clinic. The joint must be filled with a saline solution for this, as otherwise there is too little space to view the structures closely. The surgeon then inserts an arthroscope with a small camera into the joint. This allows a close look at the damage to the cartilage. After the examination, the fluid is aspirated again. 

A scintigraphy can also be useful for an accurate diagnosis. The horse is injected with a radioactive substance that is deposited in the bones and accumulates in damaged areas. This allows changes in bone metabolism to be visualized before they affect the bones and become visible in the X-ray image. Diseases can therefore be detected at a very early stage. In the following video, we explain what a scintigraphy is and how it works in horses:

Scintigraphy is relatively expensive and, according to the new GOT (scale of fees for veterinarians), costs at least almost 460 euros - not including hospitalization, sedation and other treatments. In addition, it is very time-consuming, since the agent must be processed in the body for at least two hours before the examination, which also takes an hour or more, can be started. In addition, irons must be removed from the front legs. Since the horse must be completely still during the scans, it is sedated. A scintigraphy should therefore be carefully considered.

Which diagnostics are necessary depends on the severity, localization and visibility of the osteoarthritis.

How can osteoarthritis be treated? 

As already mentioned, osteoarthritis in horses is not curable. The goal of treatment is therefore to enable the horse to live as long as possible without pain. The earlier the disease is recognized and treated, the better the chances of successful therapy. In acute phases, anti-inflammatory and painkilling drugs help. 

Hyaluronic acid

A very common method of therapy is the injection of hyaluronic acid, intravenously or directly into the joint. It is a naturally occurring component of the synovium and lubricates the joint. In addition, hyaluronic acid neutralizes metalloproteins and prostaglandins that trigger inflammation - they are so-called inflammatory mediators. In severe cases, cortisone is also administered.
Furthermore, in cases of severe damage, high-molecular hyaluronic acid or a combination preparation of high-molecular and low-molecular hyaluronic acid can be used. While low-molecular hyaluronic acid is more fluid and forms a thin film around the joint, high-molecular hyaluronic acid remains longer in the joint and forms a gel-like buffer. The injections may need to be repeated.

Hyaluronic acid can also be administered orally through the feed, which increases the level of hyaluronic acid in the blood and allows the joints to be better supplied with the substance. 

Autologous Blood:

An expensive but very modern therapy option is treatment with the horse's own blood. Autologous blood therapy originates from human medicine.
The aim is to use the body's own regenerative capacity. For this purpose, a small amount of blood is taken from the horse, which is processed and incubated in special procedures. Certain substances that are present in the blood only in small quantities are concentrated in the process, and the serum is then injected into the horse. Several portions are produced per collection, which are stored frozen and thawed before use. In osteoarthritis patients, the so-called IRAP/ACS is used. IRAP stands for interleukin, receptor, antagonist, protein and ACS for autologous conditinated serum. It works as follows: In severe osteoarthritis or arthritis, proteins (called cytokines) are released in the horse's body. These drive the degradation of cartilage. In the production of IRAP, the substances that stop these cytokines and thus cartilage degradation are to be increased. In addition, substances can be increased that ensure the regeneration of cartilage, so-called growth factors. The treatment must be repeated two to five times and costs up to 1000 euros. 

Arthroscopy: 

Arthroscopy is not only a diagnostic tool, but can also be used therapeutically. During arthroscopy, the cartilage surface is smoothed and loose fragments are removed. Therapeutic arthroscopy is often used for joint chips, but its usefulness in osteoarthritis is controversial. In fact, a 2014 study in human medicine showed no benefit over no treatment. 

Special Fitting:

In addition to therapy by the veterinarian, special shoeing can help. If the horse is to run barefoot, regular professional treatment is necessary to avoid malpositions - these put additional stress on the joint. 

Alternative Methods:

In addition to the classic methods, alternative therapy approaches can also be tried. Many horse owners have had good experiences with leeches. The small worms are attached to the horse and suck blood. This is said to have an anti-inflammatory effect. Acupuncture can also help: Long, thin needles are poked into the affected regions and are said to remove blockages in the energy flow. Special therapy boots with ceramic fibers can also help the horse. However, such approaches should only ever be tried as a supportive measure and do not replace treatment by a veterinarian.

Can a horse with osteoarthritis still be ridden? 

Generally, a diagnosis of osteoarthritis does not mean that a horse has to retire - on the contrary. Exercise is important to prevent osteoarthritis from getting worse. A good muscular condition takes stress off the joints. Lack of exercise also often leads to excess weight, which puts extra strain on the legs in particular. Nevertheless, it should not be forgotten that a horse with arthrosis is no longer as resilient as a horse with healthy joints. A long warm-up phase of at least 20 minutes is a must, so that the joint fluid can be well distributed and the cartilage is not further affected. Also, tight turns should be avoided as much as possible. Better are straight lines on soft ground, gladly also in the area - naturally here all the more attention should be paid to the ground condition. Riding at a walk over small tree trunks, roots or over poles in the riding arena can be quite helpful in encouraging the horse to lift its hooves and thus not only mobilize the joints but also train the muscles. If the arthritis is only mild, pole work at all gaits can be useful. A horse with arthrosis should not be jumped, especially if it is in the front legs - the shock absorption in the joints is ultimately limited and can no longer cushion the jump so well. Classic lunging on the circle also puts a strain on one side and is therefore not recommended. In contrast, horses with osteoarthritis benefit from work in hand, on the long reins or the double lunge on the whole track, since the additional rider weight is eliminated.
It should go without saying that a horse should only be ridden or otherwise exercised when it is free of lameness - lameness, just like "ticking", is always a sign of pain. Since osteoarthritis often also affects the horse's well-being more or less depending on the weather, the rider must be alert: Is today a good day, or is my horse acting harder than usual? Special consideration for the day's form is indispensable! 

Furthermore, for all horses, but for those with osteoarthritis in particular, plenty of free exercise is important to prevent the synovia from "falling asleep" in the first place. Ideal is an active or open stable in a quiet herd with movement incentives and sufficient possibilities to shelter from wind and rain.

How much a horse with osteoarthritis may still be worked should be discussed with the attending veterinarian. 

Which foods can help with osteoarthritis? 

No miracles can be performed with feed supplements, nor can they replace treatment on their own. But some home remedies can support the horse because they have anti-inflammatory and analgesic effects. These include: 

• Green-lipped Mussel Powder 
• MSM (methylsulfonylmethane)
• Devil's Claw
• Ginger 
• Nettle
• Hyaluron 

The supplements should be fed in short courses, as they can upset the horse's stomach if given continuously. For each horse a different remedy works best - therefore it must be tried out what helps the horse.

When does a horse have to be euthanized due to osteoarthritis? 

Osteoarthritis is now easily treatable - but not curable. If the arthrosis and the resulting pain are so severe that the horse no longer has a chance of a life worth living, then every horse owner is responsible for taking the final step at some point and putting the animal out of its misery. 

FAQ - The most frequently asked questions about osteoarthritis in horses

1. can I still ride my horse with osteoarthritis? 

Yes, exercise is actually very important for affected horses. However, osteoarthritis horses are no longer as resilient as healthy horses. The intensity of training should be discussed with the vet.

2. what can I feed my horse to help him?

Supplements such as devil's claw, ginger, hyaluron, nettle, traumel and green-lipped mussel powder can be fed to support the therapy. 

3. how can I prevent osteoarthritis in horses?

Young horses should be carefully introduced to the stress of riding. A sufficiently long walk phase should always be ridden, and plenty of free movement is also important. 

4 Which treatment is best?

This varies from case to case and cannot be answered in general terms. Talk to your vet about the right therapy.

5. can I breed a horse with osteoarthritis?

It is generally assumed that the predisposition to osteoarthritis is not inherited. However, a pregnancy, as well as mating, is very stressful for the horse, which is why it is not advisable to use it for breeding. 

6. can a young horse also develop osteoarthritis?

Yes, even if osteoarthritis is primarily a sign of wear and tear, young horses can also develop osteoarthritis as a result of too much strain or too little exercise.