What are Fusing Joints?
If the ankylosis is natural and it does not affect the horse’s performance or quality of life too much, the best thing to do is to alleviate the pain and leave it alone. However, if your horse is in obvious pain, it is important to get help from an equine veterinarian to treat the fused joints. This usually includes completing the fusion by removing the cartilage either with chemicals, a drill, or laser surgery.
Fusing joints, or ankylosis, happens when a joint that has been damaged becomes fused together as a result of severe or chronic joint disease, leaving the horse unable to move that joint. This can also be done by surgery to treat serious chronic osteoarthritis in a joint that does not have frequent or large range of motion. This stabilizes the joint and relieves most of the pain so the horse is able to continue to stand and walk on its own.
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Symptoms of Fusing Joints in Horses
If the joint fusing is caused by anything other than surgery, the signs you will notice will be:
- Unable to move certain joints or body part such as a limb
- Stiffness in the muscles in that area
- Lameness of your horse
- Pain and swelling of the affected joint
- Symptoms from underlying illness, disease, or injury
- Bony ankylosis is the connection of the bones of a joint, creating an immovable joint
- Extracapsular ankylosis is caused by the structures surrounding the joint becoming rigid
- Intracapsular ankylosis is caused by the structures in the joint becoming rigid
Causes of Fusing Joints in Horses
- Septic arthritis (infection of the joint)
- Chronic inflammation
Diagnosis of Fusing Joints in Horses
Diagnosis of fusing joints in horses should be done by an equine veterinarian or a veterinarian who specializes in horses, if possible. They are trained for these kinds of conditions in horses specifically. You will need to give the veterinarian your horse’s immunization and medical history such as previous illnesses and injury and abnormal behavior. The veterinarian will ask specific questions that pertain to the condition and you should be prepared to describe the symptoms you have noticed and what type of work your horse is used for. After the history, the first thing to be done is a complete and thorough physical examination, which includes weight, height, body condition score, breath sounds, blood pressure, body temperature, behavior, overall appearance, and heart rate. A lameness examination will be performed next, which includes flexion exam (putting pressure on the limb before movement), hoof testing, conformation, and using a joint block to numb the area before repeating the movement test. The best way to do the movement test is to walk, trot, and canter your horse in a circle and a straight line as the veterinarian describes.
An important part of diagnosis is imaging. This will include radiographs (x-rays), MRI, and an ultrasound to see the tissues and joints in the area. Contrast radiography may also be used to get a better view of the joints and tendon sheaths. In addition, testing the fluid in the bursa may be done to rule out infections. This procedure is done by using a hypodermic needle to extract the fluid and sending it for microscopic examination. The veterinarian will also want to do some diagnostic tests such as urine cultures, bacterial and fungal cultures, serum chemistry analysis, a complete blood count (CBC), and glucose test.
Treatment of Fusing Joints in Horses
There are many different choices of treatment for fusing joints. Some of the most common are:
Some of the medications that may be used on your horse are hyaluronic, intra-articular steroid medication, nonsteroidal anti-inflammatory drugs (NSAIDS), hyaluronic acid, polysulfated glycosaminoglycan (PSGAG), and polysulfated glycosaminoglycan.
During this procedure, the veterinarian will remove the cartilage lining of the joint with a surgical drill. By removing the cartilage, the bones will fuse themselves eventually. However, it could be painful and may take up to a year for fusion to be done.
This is done by injecting some kind of caustic chemical into the joint, which destroys the cartilage. However, there are some serious complications with this treatment that may happen in the chemical is accidentally injected into the hock joints.
In this procedure, the veterinarian will use a diode laser to remove the cartilage. The joint will then be stabilized and supported until it heals.
This is done by trimming one of the sides of the feet shorter than the other to put more pressure on that side.
Extracorporeal Shockwave Treatment (ESWT)
A probe will be affixed to the skin and an electrical charge is sent to the probe. This creates a force on the tissues that encourage healing.
Recovery of Fusing Joints in Horses
The veterinarian will likely prescribe NSAIDs, confinement, and support with bandages. Hand walking will begin after about three weeks with turnout after 30 days. You should proceed with an exercise program slowly and within about four months your horse can return to normal routines after approval of the veterinarian.