The radiograph seen here shows the foot of a middle-aged Welsh Pony mare that presented to our team for chronically sore feet. For the past couple years, the pony would develop sore feet in the spring that be intermittently sensitive until the fall months arrived. This year, however, she seemed worse than ever and so we were called to investigate. On examination, she was lame at the walk in both front feet. Radiographs were taken and showed that her coffin bone was rotated in both of her front feet. These images lead to a diagnosis of laminitis, commonly known as “founder.”
In order to understand this condition, it is important to have a good knowledge of the anatomy of the equine foot. The inside of the hoof wall is “glued” to the coffin bone by tiny structures called laminae. Both the hoof wall and the coffin bone are lined by these laminae, which interlock to hold the two parts together. This works to transfer the horse’s weight from the skeleton to the hoof wall, so that the coffin bone itself does not have to contact the ground surface. If these laminae become inflamed (called laminitis), they fail to interlock, and the coffin bone separates from the inside of the hoof wall. It can then rotate or sink down within the hoof capsule.
Many different conditions can cause the laminae to become inflamed. Some common examples are a high-sugar diet (eg. lush pasture or getting into the grain bin), Pars Pituitary Intermedia Dysfunction (also called Cushing’s Disease), Equine Metabolic Syndrome, systemic bacterial infections, and excessive concussion on a hard surface. While there are many paths to laminitis, the result is the same: moderate to severe pain in the horse’s feet. If you suspect your horse has laminitis, contact your veterinarian. He or she will perform a thorough examination and may recommend further testing to get an accurate diagnosis of the cause of the laminitis.
Treating laminitis takes a team approach and your veterinarian and farrier will work together with you to devise a treatment plan for both the initial cause of the laminitis as well as the current problems in your horse’s feet. This is often a long process requiring many months of recovery. The pony in this case tested positive for Pars Pituitary Intermedia Dysfunction, and was started on medication for this condition to prevent further laminitic episodes. Her farrier also performed a corrective trim and applied special shoes to help her remain comfortable in her healing process.