My horse has been diagnosed with bone spavin. I’m concerned that this is the end of our competitive career and she is only nine.
Answered by Sarah Wanless
Bone spavin is a scary term for anybody in the horsey world, and many associate it with having to put their beloved competition horse out to pasture. The good news is that that isn’t necessarily the case anymore.
What is bone spavin?
Bone spavin is caused by osteoarthritis in the hock of the horse, and it causes a hindlimb lameness that occurs in many higher-level competition horses, especially those who compete in showjumping or dressage. Bone spavin manifests itself in the hock joints as boney outgrowths that cause pain, inflammation and limit the range of motion of the joints. It can affect either one or both of the hocks.
Bone spavin usually affects the lower two hock joints, the tarsometatarsal joints and the distal intertarsal joints, with the third joint, the proximal intertarsal joint, being the least likely to be affected. Younger horses are also susceptible to a form of bone spavin called juvenile spavin, which usually arises as a consequence of certain congenital diseases.
Causes
There are several causes of bone spavin:
- Conformation Horses who are sickle-hocked or cow-hocked have a higher chance of developing bone spavin later in life due to the undue pressure these conformational faults place on the hocks. The more pressure that is on the hocks, the faster osteoarthritis progresses and the quicker boney outgrowths develop.
- Incorrect shoeing can cause excessive loading of the hock joints, leading to severe compression of the cartilage on one side of the joint and then joint strain on the opposite side. This typically causes the excessive growth of bones as part of osteoarthritis, and then symptoms of bog spavin develop.
- Genetic susceptibility Certain breeds, especially heavier breeds like Boerperds and Icelandic horses, have a much higher chance of developing bone spavin later in life, irrespective of the type of work they do.
- Overworking and repetitive motion Competition work, especially the work we do with our horses today, often requires excessive flexion of the hocks. This increases the concussive forces in these joints, which in turn increases the degree of compression of the cartilage. Over time the cartilage is compressed and eroded, which results in a decrease in joint space and an increase in the chance of new bone growth developing, as occurs in bone spavin.
Symptoms
There are several symptoms of bone spavin and they vary in the degree to which they affect the horse. The more severe the bone spavin, the more severe the symptoms will be:
- Dragging of the toes of the hindlimbs
- Stiffness, particularly in the hindlimbs
- Progressive hindlimb lameness
- Unusual/irregular stride length
- Uneven hoof wear
- Decreased performance levels
- Reluctance to work in a previously willing horse
If any of these issues present themselves, it is advisable to contact your vet and ask them to come out for an examination. While a full body examination does help in ruling out any other causes of lameness, it does not definitively diagnose bone spavin. This is usually done with the use of radiography (particularly x-rays), intra-articular injections of local anaesthetic or scintigraphy.
Treatments
There is no cure for bone spavin, and it is a condition that will need to be continually managed throughout your horse’s life in order to keep her sound and comfortable. The good news though is that it can be managed reasonably effectively. There are a number of medical and technical treatments:
- Corrective shoeing can help to ease and reduce any pain or inflammation. The use of wedges, squared/rolled toed shoes and egg bars is often recommended by farriers.
- The use of systemic (taken orally or injected) non-steroidal anti-inflammatory drugs (NSAIDs) are useful in helping to reduce pain and inflammation.
- Corticosteroid injections into the lower hock joints can alleviate lameness for months at a time.
- Surgery can be performed to fuse the joints.
- I-RAP (Interleukin Receptor Antagonist Protein) helps prevent further degeneration of the joint. The creation of I-RAP involves taking blood from the horse and then using the horse’s own anti-inflammatory mechanisms to create an anti-inflammatory product from that blood. This blood is then injected back into the horse, but this time into the joint to help prevent further degeneration and ideally promote healing.
There are also a whole lot of other, less medical approaches that you can use to help your horse on a day-to-day basis:
- Riding your horse every day helps to ensure that the joint remains lubricated. Ridden work or groundwork is great, but lunging is not recommended as it can increase the pressure on the affected hock joints.
- Making sure your horse is strong physically can help to alleviate some of the pressure on the hocks.
- Increasing paddock time can help, as it reduces the amount of stable stiffness that your horse develops by keeping the joints more lubricated through movement.
- A decrease in the intensity of the workload can also be of benefit. Longer but lower intensity workouts on a regular basis are considered optimal, as they allow the horse to lubricate the joint without putting excessive pressure on it.
- The use of ice and vibration together can be a powerful combination in helping to reduce the inflammation within the joint.