Arthritis in Horses

Arthritis is a degenerative joint disease that causes symptoms like stiffness, inflammation, and pain. Just like humans, horses can develop and suffer from arthritis. Arthritis is almost unavoidable as horses age, but early diagnosis and conscientious care can slow its advance and minimize pain. A vet can run many tests and a thorough body examination to determine whether or not your horse has arthritis. 

What Is Arthritis?

Osteoarthritis is a degenerative joint disease (DJD) involving the breakdown and loss of the cushioning cartilage that lines the end of bones within a joint. With this breakdown, there is also a loss of lubricating joint fluid, and the joint as a whole loses its ability to cushion impact and provide a gliding surface during motion. This then results in joint pain and leads to lameness in horses. Arthritis in specific locations in horses goes by common colloquial names such as ringbone and bone spavin.

Symptoms of Arthritis in Horses

The symptoms of arthritis in horses are painful and largely inhibiting motion. If your horse is experiencing any discomfort or you suspect that your horse has arthritis, pay a visit to the vet right away.

In its early stages, arthritis may appear as a slight stiffness that the horse overcomes once they are warmed up. In the joint, the cartilage material is breaking down but not repairing itself efficiently. Eventually, as the cartilage becomes more damaged, the bone beneath the cartilage pad becomes damaged too. The horse will experience more discomfort and even heat in the joint as inflammation occurs. As the disease progresses, the horse may experience more pain and lameness. In more advanced cases, small bony growths called osteophytes may be seen under X-ray and may be felt around the affected joint.

Causes of Arthritis

Arthritis is caused by the wear and tear of cartilage—the tough, flexible tissue that is the sliding, shock-absorbing surface between the bones that meet at a joint. Over time, compression and stress wear away the protective cartilage. Arthritis most commonly occurs in the weight-bearing joints of the legs. Extra stress or injury to any joint can lead to arthritis.

Specific sports can make a horse more susceptible to arthritis in certain joints due to repetitive concussive force. Certain types of conformation in a horse can also make it more prone to the development of arthritis. However, as all horses age, as with humans and other animals, repetitive wear and tear cause damage of varying degrees to high motion and weight-bearing joints.

Equine arthritis can affect any mobile joint in the body, including the knees, shoulder joints, spine, fetlocks, hocks, and stifles. These are all weight-bearing joints. The fetlocks, knees, coffin bone (within the hoof), and hocks are most commonly affected.

Diagnosing Horses With Arthritis

To diagnose your horse with arthritis, you will need to visit a veterinarian. The vet will perform a full body examination, review medical history, and conduct a series of X-rays. Your vet might also request a sample of joint fluid to check for infection. Other diagnostic procedures may include MRIs, a nuclear bone scan, nerve block examinations, endoscopy, and blood and urine tests. 

Treatment

The goal of arthritis management is to reduce the inflammation in the affected joint, relieve pain, and slow further damage to the joint.

If you notice that your horse is having any discomfort (even discomfort that wears off quickly), it's a good idea to consult your vet. Your vet may be able to identify arthritis early and slow its progress with drugs that reduce inflammation.

Once the cartilage in a joint is damaged or gone, it is difficult to repair it. Discomfort can be managed by joint injections of joint fluid supplements like hyaluronic acid and polysulfated glycosaminoglycans and corticosteroids. You can also use oral non-steroidal anti-inflammatory (NSAID) drugs such as phenylbutazone for pain management. However, long-term use can have negative side effects such as gastric ulcers and the potential for kidney damage.

For longer-term treatment, medications include firocoxib (an NSAID that works differently than phenylbutazone) and diclofenac sodium, available in a topical cream. Some clinicians are exploring various stem cell therapies. In some cases, depending on the horse and what joints are involved, this modality may also be an option. Shockwave and laser therapies may also be considered.

In addition to veterinary treatment, a reduction in workload may be necessary, mainly if the work includes jumping, traveling over rough terrain, or other activity that potentially over-stresses the joints. Although light exercise is essential to maintain joint flexibility, this may mean the end of a horse's competitive career. When the horse may be lame, it should not be ridden. Keep the horse on soft footing, with extra but not excessive bedding that may be hard to walk through. Proper trims and shoeing by a knowledgeable farrier may also be helpful.

Prognosis for Horses With Arthritis

When diagnosed early and managed adequately, you can completely resolve arthritis in horses. Chronic arthritis may persist if the horse doesn't respond to anti-inflammatory treatments or if infection occurs during the healing process.

How to Prevent Arthritis in Horses

Arthritis, to some degree, is almost unavoidable in older horses. Horses with conformation faults may put extra stress on joints, yet another reason why breeders strive for foals with good conformation. Proper hoof trims and shoeing, good conformation, sturdy footing, and good basic maintenance can also help delay the onset of arthritis.