If your equine is acting poorly, it may need worming or some other medical treatment instead of, or in addition to, feed additives. If the animal is showing signs of arthritis, then, of course, the owner wants to give it needed relief.
Many experts recommend not giving the sufferer any pain reliever, since it may turn off nature's way of saying, "Don't do that." In other words, your horse might not know he or she should not walk a lot of bad legs, because it no longer hurts to do so.
Equine joint supplements should have nutrition that will aid the tissues in growing and healing, and not just mask the pain. Glucosamine Sulphate is considered one of the best for this. Chondroitin Sulfate is another that is frequently praised as very helpful for arthritis and other issues arising from joint damage.
If you decide you need joint supplements for horses, they are often sold at veterinary offices and your vet may be able to recommend a good one. However, you can also go online and search the Web for the best kinds and often save a great amount of money doing so.
Many websites will sell them and let customers write reviews. By reading the reviews that are purportedly written by legitimate customers you can at least know how many people reported seeing good results.
You could get a recommendation from your vet, but still shop online, where you can get more opinions on its effectiveness and maybe find a better price.