OVC’s state-of-the-art MRI allows researchers to track changes in horses’ hooves in an effort to reduce lameness, improve performance
BY BARRY GUNN, OVC
Chinese traditional medicine teaches that good health for humans starts in the feet. The same holds true for horses. And cutting- edge imaging research on horses’ hooves at OVC may provide long-term benefits that reduce lameness and aid performance of equine athletes and pleasure horses. Just as muscles and bones respond to work — when things go right, by getting bigger and stronger — the tissues that make up the horse’s hoof will change in response to the stresses of walking and training. But those adaptive changes can be advantageous or disadvantageous, and it isn’t always clear why. By using OVC’s state-of-the-art magnetic resonance imaging (MRI) unit, scientists will for the first time be able to examine the feet of living horses to track those changes. Previously, studies were limited to using the hooves of dead animals. “What’s unique about what they’re doing is that there is no other non-invasive way to get the level of detail that we believe we’ll be getting with the MRI,” says Prof. Howard Dobson, a radiologist at OVC’s Veterinary Teaching Hospital, who is consulting on the project. In addition to studying live subjects, Prof. Jeff Thomason, Biomedical Sciences, and PhD candidate Babak Faramarzi hope to break new ground using specialized software to analyze the data and custom modifications to the MRI unit to maximize the resolution of the images. “We’re taking technologies developed in human brain research and applying them to the horse’s foot,” says Thomason. Providing technical expertise for the project are medical physicists Michael Noseworthy of McMaster University and Norm Konyer of St. Joseph’s Hospital in Hamilton. Konyer is building a customized coil — the antenna that receives the signals from the object being scanned — to make it wrap around the hoof for a clearer image. “There’s enough evidence from the images we have so far that we’re fairly certain we’ll be able to get the resolution we need,” says Thoma- son. “That’s why we’re sticking with it. There is no way an equine field MRI could do this kind of imaging.” The project, which is still in the preliminary stages but should hit full stride by early summer, will use MRI to study the laminar junction — the layers of tissue that connect the hoof wall to the distal phalanx or coffin bone. It’s the laminae that transfer the forces of weight-bearing from the coffin bone through the hoof wall to the ground. In effect, the coffin bone, and therefore the horse’s weight, is suspended from the inside of the hoof wall by these delicate structures. The study will focus on two groups of 10 horses. One group will undergo an exercise regimen over six to nine months; the control group will not. Faramarzi and Thomason will use MRI at the beginning, end and middle to document differences in the laminae of the two groups. The MRI will allow them to examine the orientation, density, strain patterns and growth rate of the laminae in greater detail than ever before. It will also allow them to continually modify their techniques to get the results they need. “With an MRI, there are so many variables we can study,” says Fara- marzi. “Even though MRI may not provide a clear image of each lamina, the calculations can tell us about them without actually seeing them.” If all goes according to plan, the researchers will be able to publish a protocol for using MRI to examine the laminar junction. They may also provide veterinarians with a new diagnostic tool for dealing with laminitis, a devastating condition with a variety of manifestations and causes that aren’t well known yet. Eventually, the research should provide new information to help farriers refine their trimming and shoeing techniques, says Thomason. “The whole industry is based on observation and trial and error, which is fine because they have thousands of years of experience to build upon. I’d like to get it on a more scientific footing and add a degree of predictability that’s not there now.”
