Common bone problems

By Gil Riley

Veterinary Advice

09 March 2012 13:39

It’s often hard to see the light at the end of the tunnel when your horse has a fracture or bone condition but don’t despair as there are options. We speak to Equine vet Gil Riley who talks us through some of the most common skeletal problems… 

 

Osteochondrosis dissecans (OCD)

Osteochondrosis dissecans is a common and painful disease characterised by an abnormality in the cartilage-to-bone transformation. As a result, cartilage and bone fragments may break off into the joint space. This is particularly common in Thoroughbreds and warmbloods and often develops in young horses (usually at yearling stage) and comes to light when they’re brought into training.

More often than not in OCD cases, the joint will swell up and be obvious, but there are cases where no external features are present and the horse will simply appear lame.

OCD is most commonly found in the hock but can also occur in other areas of the leg and even in the shoulder.

Most cases of OCD have a good prognosis – an operation to remove the fragmented bone and smooth any uneven surface is usually successful. However, in cases where the bone is actually deformed (for example, in the shoulder or the neck) the prognosis is not so positive.

OCD can occur in more than one area of your horse so it’s vital that if your horse has OCD present in one hock, the other hock must be x-rayed too, to check there’s no OCD present there.

 

Ringbone (pictured above)

Ringbone is essentially osteoarthritis of the joints. When it occurs in the coffin joint it’s known as lower ringbone and when it occurs in the pastern it’s known as higher ringbone. Ringbone is common in cobs and heavier breeds as well as older horses.

Commonly with ringbone there’s a delay between the original cause of the condition, whether it’s injury or conformational faults, and the actual problem becoming apparent.

When ringbone is present the horse will go lame. It cannot be cured but simply has to be managed using either anti-inflammatory injections straight into the joint, such as steroids, or using an oral anti-inflammatory painkiller, such as bute. Osteoarthritis is actually an attempt to stabilise the joint, so when it occurs in a joint that needs to be mobile it can have a very negative effect but in a less mobile joint, such as the lower hock, the osteoarthritis can actually allow the horse to come sound again.

Using gentle exercise and bute is the best way to manage the situation.

 

Bone Chips 

Bone chips are most common in racing Thoroughbreds and often occur in the knee bone. This is caused because the knee is the only joint within your horse’s body that bares maximum weight at the maximum point of extension, which is why even a slight over-extension can cause a chip. The bones in the knee are tightly packed together so when put under extreme pressure they can chip.

Bone chips are treated by surgical removal and generally have a good prognosis for the future.

Your horse should be able to return to his usual work and make a full recovery with anything treated surgically, such as bone chips and OCD, but osteoarthritis is a condition that needs careful management and may require the rider to change their goals and reduce their horse’s workload.

 

Stress fractures 

Stress fractures are a real possibility in all horses but particularly racing Thoroughbreds and usually occur following trauma. Given plenty of time and a gentle introduction back to work, these fractures can heal well.

Often, with a stress fracture, the horse will simply show some lameness (no swelling or exterior problems) meaning that, after a week of box rest and as the repair process begins, your horse may seem sound but in fact the fracture is trying to heal and will only heal successfully if given enough time. If your horse is returned to work too quickly, the fracture could break completely.

Stress fractures can occur in the long pastern bone, lower part of the cannon bone, tibia and pelvis.

The best way to manage a stress fracture is to introduce him back to work gradually. Box rest him for a few weeks before introducing him to walking work for a four-week period (10 minutes twice a day, progressing to 30 minutes twice a day) then moving onto ridden road work with short spells of trot, and so on.