X-rays Changes Common In Elite Equine Athletes

For both you as a horse owner and trainer and myself as a veterinarian evaluating pre-purchase exam x-ray findings is a challenge. You will get a great deal of information and it can be hard to determine which findings are significant enough to avoid making a purchase and which findings you can accept as part of purchasing a horse, especially one who is engaged in an athletic life.
 
A recent study designed to examine x-rays of Grand Prix jumping horses actively engaged in competition and performing well brought up some very interesting information.
 
X-rays were taken of 44 horses competing in and earning top ribbons in Grand Prix jumping competitions at the Thermal-Hits winter circuit, Pebble Beach Equestrian Center, the Wellington, FL Winter Equestrian Festival, and the Kentucky Horse Park. X-rays were taken of front hooves, fetlocks, stifles, hocks, and other areas. A total of 40-44 images were taken of each horse. The median age was 12 years old with a range of 7 to 17 years. Most were warmbloods and on average they had competed at the Grand Prix level for 3 years. 
 
So what was found?
 
All horses demonstrated some abnormalities on their X-rays. That is right.  Every single one of the 44 horses had some abnormality noted on their X-rays. In fact, all horses had abnormalities noted in 2 or more places with the median number of places found with abnormalities being 7 and a range of 2 to 11 sites. As you might expect, most of the abnormalities noted were minor.
 
Common findings in the front hooves and pastern. 
 
Of the 44 horses only 10 had no abnormalities detected in the front hooves. So 77% had some abnormal findings in the front hooves and pasterns. 20% (9 of 44) had changes in their coffin joint. On a scale of 0-3 for the navicular bone changes 28% were grade 1, 11% were grade 2 and 2% were grade 3. Together 43% of the navicular bones examined had changes that put them above a grade 0. Remember all these horses were both competing and doing well in Grand Prix jumping competitions.
 
This goes along with my findings over the years and also is in line with what other studies have found. You have to look at x-rays of the navicular bone and judge whether or not there are changes and then consider how likely any changes found are likely to go on to cause a problem.  
 
Here is an example of a great-looking navicular bone:

Here is an example of a poor looking Navicular bone:

It is important to note that the horse with the large changes in the navicular bone was perfectly sound and was a high-level competition reining horse. 
 
But, if you were thinking of purchasing this horse, you would have to think long and hard about purchasing a horse with these significant changes in the navicular bone.
 
Of 88 front fetlocks examined 51 of 88 (58%) had bone spurs. Most were small but a variety of other changes were noted such as one horse with a fracture at the end of a splint bone and the fetlocks of several horses had bony projections from the upper pastern bone near where ligaments attach.
 
The hind fetlocks showed fewer issues, but 40% of the fetlocks demonstrated some abnormality.
 
Of the 88 hocks examined 56 of 88 had some abnormality (64%). Most of the issues were small spurs in the lower two hock joints - these are the two joints where "bone spavin" occurs.  27 of 88 of the hocks (35%) had changes in the joint one up from the bottom of the hock and 43 of 88 hocks (49%) had changes in the joint at the bottom of the hock where it meets the cannon bone.

What does this all mean?
 
In elite show jumpers who are performing perfectly well, it is clearly not unusual to find multiple small changes on X-rays in hooves, fetlocks, hocks, and stifles. Mild to moderated arthritic changes were common in the fetlock and hock joints. Several horses showed changes in the bone at the upper attachment of the suspensory ligament, yet they were actively competing.
 
A survey of this type can put in perspective that some abnormalities are common, especially if you are purchasing an active long-term competition horse. Given that so many findings were present among this group of elite athletes, it is reasonable to take that into account before rejecting an otherwise sound horse if similar findings are discovered during a pre-purchase examination.