Joint Health.

A look at a range of supplements and herbs which can help with joint health

Unlike almost all other domesticated animals we keep horses for their athletic ability. Because they are expensive to keep we also aim to have them performing as soon as possible. Unfortunately this sometimes means that they are subjected to the rigours and stress of training at too young an age. This can result in the early onset of arthritis so often seen in the lower leg joints. This form of arthritis is called degenerative joint disease (DJD).

Studies in the USA have shown that genetics is the most important influence on joint degeneration. So the choice of sire and dam is important. Next in line is the age at which the horse starts training, followed by the extent of the horse’s preparation for shows or sales. The reason for this is that they tend to put on too much weight too early in their development. To have a better understanding of why this is so we need to look at some of the detail of a joint.

For bones to grow they need to increase in width and length. To increase width the bone material is removed from the inside and deposited on the outside. To increase in length bones grow from the epiphyseal plate. There is one at each end of all long bones. Excessive growth and inflammation exhibits as epiphysitis in young horses. If young animals are overfed, are carrying too much weight or are forced to train hard too early this process of bone maturation can be upset and result in joint problems at a later stage. It is important to remember that the musculo-skeletal system in a horse does not mature until 3 years of age at the earliest. Some breed may take up to 5 years.

The joints are the main part of the skeleton that can cause problems in the athletic horse. They are complex structures made up of several different types of tissue.

In the middle of a joint is a capsule of synovial fluid. This capsule is responsible for supporting and protecting the joint and maintaining the normal range of motion. On each side of the capsule is the cartilage and then the epiphyseal plate. Have a look a chicken thigh bone and you will see all these structures quite easily. The joint itself is held together by ligaments . The cartilage is a very important part of the joint and that which seems to cause the most problems. It is a matrix structure including collagen. Within the structure itself are chondrocytes which are the cells responsible for collagen metabolism.

Problems with joints often arise because they tend to heal quite slowly. Although bone is well supplied with blood vessels, ligaments are not. This means that they find it hard to get sufficient nutrients and other things supplied by the blood and so heal slowly following damage. This poor vasculation does not affect a ligament’s ability to become inflamed as the white blood cells migrate out of the blood to the area of damage. White blood cells play a major role in the inflammation process. Although the inflammation process is the same in all types of tissue it is more complicated in a joint. Here inflammation is responsible for stimulating the degradation of the chondrocytes and reducing synthesis of matrix molecules. This results in a cartilage matrix with poor mechanical properties.

Inflammation is part of the immune response but as we have seen can have some detrimental effects. To support the joint there are two approaches that we can look at. Firstly we can try and help the integrity of the joint by supporting the matrix of the bone, cartilage and joint fluid. Secondly we can help to inhibit the degradation of the joint by preventing damage and reducing inflammation.

The goals of joint therapy, from whatever your viewpoint, must be to: decrease pain, decrease disease, increase longevity of the joint and maintain performance and quality of life.

The term chondroprotection is used by vets to describe the medications that use certain chemicals found in the cartilage matrix. These include glucosamine and chondroitin. The theory is that making excessive amounts of these chondroprotectors available will enable the body to more quickly repair any cartilage damage. The differing approaches still seem to be generating a fair degree of discussion in the scientific press with studies showing diverse results. Indeed it does seem that the major effect that most supplements are having is in their anti-inflammatory effect. The prevention of inflammation prevents the degradation of the cartilage which in turn allows the joint to recover in the way that it should.

Although they are widely used, we have some concerns with the use of animal by-products on horses. After all they are herbivores. Glucosamine is extracted from chitin which is the exterior skeleton of crabs, shrimps and lobsters. Chondroitin can be extracted from the cartilage of sharks, poultry or cattle. It seems that the most usual source is cattle. Although I am quite sure that the appropriate controls are in place the feeding of a beef extract to horses is of concern. Particularly when suitable plant extracts are readily available.

The Herbal Approach

As herbalists we try to look at the cause of a problem and treat the whole animal. The approach is to look at the lifestyle factors as well as just giving herbs.

The main factors to look at are:

• Nutrition. A good diet is important to make sure that all the building blocks are available.
• Rest. In acute cases of joint injury rest is important. In chronic cases however, continued moderate exercise is important.
• Internal anti-inflammatories. As we have seen when the joints are working to their limits some inflammation is inevitable. This means that a level of anti-inflammatory treatment may be justified at all times that a horse is in work.
• Topical treatments can also be used in support after hard work or if there is an acute injury.

If we take it that the major factor in preventing degenerative joint disease is the prevention of inflammation then there are several herbs that we should consider. Some act directly on the tissue concerned whilst others have traditional use in the treatment of arthritis or gout.

White Willow and Meadowsweet are two traditional herbs that are well known and often quoted as the original source of what we now call Asprin. However they both contain measurable levels of salicylates. We have not tested them but prefer not to use them on horses for fear of causing a positive swab. Herbs that should not swab and which are readily available include Celery seed, Turmeric, Ginger and Devil’s Claw. We have had greatest success with Devil’s Claw. It is readily available and horses find it quite palatable (unlike some of our human patients).

Certain long term degenerative diseases may be affected by a build up of uric acid in the joint. Uric acid is a by product of the inflamation process and is the cause of gout in humans. Nettle leaf is particularly effective in treating this condition and would certainly be worth including in a treatment regime for an older horse with chronic arthritis.

Another herb which is reputed to help with joint health over a long term is Raspberry leaf. A herbalist in Melbourne has been doing trials on humans and reports good success. Buying raspberry over an extended period would get quiet expensive but if you have some growing it would be well worth harvesting and drying the leaves for later use.

A few hints may help to delay the inevitable deterioration and onset of DJD. Unfortunately once DJD has started the prognosis is for a slow decline. Most horses will be affected by their mid teens.

• resist the temptation to work young joints too hard.
• try not to allow young horses to become too heavy.
• as they get older slowly increase the work level.
• use appropriate work/rest cycles.
• after a hard work session allow 48 to 72 hours rest for the joints to repair.
• use appropriate anti-inflammatories when the horse is in work.
• if your horse becomes lame keep a diary. Note what makes the lameness better or worse, which anti-inflammatories work and which don’t.
• finally when you work make sure you allow adequate warm up and warm down periods.

The best advice is probably to experiment with your own horse. Individual horses will respond to different ways to the products that are available. So find what works best for your horse.

Remember, joints are complicated structures that are often working to the limits of their physical capacity so if you have any concerns about the welfare of your horse talk to your trained equine herbalist or vet.

© James Hart