Page 112 - January 2019

same as IRAP (interleukin-1 receptor antag- onist protein), have shown some significant benefits for treating joint disease. Another new treatment modality gaining popularity is injection of a long-acting hydrogel into the joint, which acts as a synthetic lubricant. This product, which has been used pre- dominantly in Europe and is in the process of gaining FDA clearance in the U.S., has shown benefits in horses with osteoarthritis of the coffin and pastern joints,” he says.
Horses with abnormal hoof-pastern angles or hoof wall imbalances can be prone to repetitive trauma to the coffin joint, which can lead to low ringbone. “Proper hoof care and therapeutic shoeing can help alleviate these abnormalities,” says Herthel.
There is often a lot of pain with low ringbone, since this joint is inside the hoof. Any swelling or enlargement creates pressure and pain due to the restricted space within the hoof wall.
“There are surgical techniques to fuse the coffin joint, but these are just salvage procedures. Those horses will not be able to return to an athletic career. These efforts are simply aimed at making the horse more comfortable for pasture soundness or breed- ing,” he says. Even this would be done on a
In the early stages of ringbone, the veterinarian will need to determine where the pain is coming from by pinpointing the source, which may entail palpation and flexion of the limb.
“High ringbone” involves the pastern joint and will cause a bony growth around the pastern area and the pastern will have less mobility. “Low ringbone” involves the coffin joint, causing moderate lameness and when severe, you can see the bony growth on the coronet.
case-by-case basis because a broodmare will have more weight and pressure on the joint when she is heavily pregnant, which could result in more discomfort. Pain is a form of stress, which can alter hormone profiles for reproduction and negatively affect fertility.
DIAGNOSING RINGBONE
A traumatic injury will be immediately obvious as acute lameness, and a veterinar- ian can determine the location of injury. If the joint problem is not acute but rather due to cumulative or repetitive stress, the first thing you might notice is mild to moderate lameness. “Observable signs of ringbone, such as enlargement around the joint, would not be evident until a much later stage of the disease,” says Herthel.
“In early stages with mild or acute lame- ness, the veterinarian’s job would be to determine where the pain is coming from. Pinpointing the source may entail palpa- tion and flexion of the limb, and possibly some regional or intra-articular nerve blocks. Usually radiographs of that area are adequate to confirm the diagnosis. Though if the injury is acute, the veterinarian may need to use other diagnostic methods such as an ultrasound, bone scan, CT, or an MRI examination to confirm the diagnosis, especially if it’s an acute injury or a small cartilage defect that we are unable to see on radiographs,” he explains.
TRIMMING AND SHOEING THE HORSE WITH RINGBONE
Allen says corrective shoeing can often help horses affected by ringbone. “I always start with a good base trim. Then I prefer to put shoes on the horse, so I can control the hoof wear. If the horse is lame, he probably needs shoes to control the wear and to influ- ence the way the foot breaks over and moves. This enables us to give the horse some relief from too much stress on the affected joint.” Allen always tries a conservative approach
at first, but if that doesn’t work, he doesn’t hesitate to “go outside the box” and try
other things that might help. Sometimes the weight of a shoe can be a disadvantage, so it’s always a case-by-case situation.
“More than likely, the foot is going to wear the opposite way from how I need to trim it and keep it trimmed, so shoes can help. The foot needs enough shoe to support and complement the trim. It usually needs a little more support on the rear of the foot.” Heavy shoes may be a disadvantage, how- ever, so an aluminum shoe might be best.
“Paying attention to break-over is very important. We move it back, making it as easy as possible for that horse to break over. Right before the foot breaks over, that’s when those joints have the most pressure and tend to close up a little. I want that foot off the ground quicker, so it is non-weight- bearing as quick as possible,” Allen says.
“Surgical fusion for high ringbone is very successful, whereas fusion for low ringbone is rarely done and is purely a salvage procedure.
108 SPEEDHORSE, January 2019
EQUINE HEALTH