"Magnetic resonance imaging (MRI) has added to our knowledge of navicular disease, in large part because for the first time we can see into the horse's foot," said Robert Schneider, DVM, MS, Dipl. ACVS, equine orthopedic surgeon at Washington State University's Veterinary Teaching Hospital. His presentation at the 2003 convention of the American Association of Equine Practitioners focused on what he has learned about using MRI to diagnose and evaluate treatments for navicular disease and nearby pathologies since 1997.

"MRI has proven to be a valuable tool for making specific diagnoses in horses with performance-limiting lameness problems," he stated. "Navicular disease is one of the most common causes of performance-limiting lameness in many types of athletic horses. Despite the high incidence of the disease, our understanding of the problem is relatively limited.

"Equine practitioners have long suspected that there were multiple problems in the foot that caused similar clinical signs," he continued. "Because of the limitations of radiographs, many causes of bilateral (in both front feet or both hind feet) foot pain were recognized and diagnosed as navicular disease. MRI has allowed us to begin to differentiate some of these problems from navicular disease."

He described the different types of MRI images that can be obtained; some allow the practitioner to better visualize fluid in bone and soft tissues, while others yield better detail for imaging anatomical structures