Cutting-edge technological advances for diagnostic equipment are giving equine practitioners new ways to diagnose disease and injury.
Take magnetic resonance imaging, for example.
"The horse that needs an MRI is already injured,” notes Dan Brown, BVSc, ACIM, MRCVS. "Using a standing MRI removes the risk of worsening that injury as the horse comes out of general anesthesia.”
Dr. Brown says the accuracy of standing MRI and traditional "down” MRI scans are nearly the same at about a 90 percent diagnostic rate.
Brown is the business development director of Hallmarq Veterinary Imaging Ltd., manufacturer of the world’s only standing MRI. Hallmarq’s factory and main office are in Guilford, United Kingdom; its U.S. sales and service office is based in Acton, Mass.
First developed in the UK and used throughout Europe, standing MRI is rapidly gaining acceptance among American veterinarians and is a "really useful tool in making a quality diagnosis” for injured horses, says Brown.
For Karen Blake, DVM, Dipl. ACVS, all MRI and computed tomography scans are the new standard in diagnostic equipment. She is an equine lameness expert as well as a board-certified equine surgeon and owner of Elite Veterinary Services in Park City, Utah.
"MRI is an evolving imaging modality that is allows for early identification of equine orthopedic injuries,” Dr. Blake says. "It allows us to provide an accurate diagnosis and targeted therapy.”
Blake was first exposed to advanced veterinary imaging techniques when she was a resident at University of California, Davis, where she used MRIs and CTs as diagnostic and teaching tools.
"With today’s scans, we are able to get a better understanding the pathology of problems with the foot, the sinus cavity and more,” she says. "Another benefit: The images give us a baseline we didn’t have before (their widespread use).
"MRIs and CT technology also allow veterinarians to make earlier diagnostic decisions than we did in the past,” she says. "The images’ accuracy shows minor changes, before disease progression escalates. We can go back and re-evaluate treatment, as well as monitor progress in healing.”
"Superior MRI images have revolutionized the diagnosis of orthopedic disorders in horses,” says Anthony Blikslager, DVM, PhD, of North Carolina State University College of Veterinary Medicine.
Dr. Blikslager is professor of surgery and gastroenterology in the college of Veterinary Medicine at North Carolina State University.
"Normal and abnormal scans may be evaluated with unsurpassed clarity, allowing an accurate diagnosis and more specific treatments,” he says.
"Standing MRI is producing better images because of improvements in equipment and software that corrects for movement,” he says. "However, it is still mostly limited to imaging the foot, as motion becomes more of a problem the higher up the limb you go.
"The high field magnets, which require general anesthesia, are seeing increasing use to the point where MRI may be selected instead of radiographs,” Blikslager says. "Standing CT is a much more recent development, and offers exciting possibilities for diagnosing diseases of the head,” Blikslager says.
"While CT has been available for a long time, the need for general anesthesia has limited its use,” he says. "With standing CT, there is now the possibility of advanced imaging of complex diseases of the teeth or sinuses, which often require a 3D image to fully appreciate.”
Blikslager says there are studies under way using overground endoscopy for diagnosis of upper airway disease in horses as they are exercised with a rider.
"This provides the dynamic endoscopy needed to properly diagnose conditions such as dorsal displacement of the soft palate without the need for a treadmill,” he says. "In addition, a treadmill does not simulate natural exercising conditions. Footage from the overground endoscope is transmitted and watched in real time.”
Another interesting diagnostic development is the SmartPill, which images the gastrointestinal tract. It literally sends images as it travels down the gut. Though the device has been used in human medicine with good results, the capsule is still under study for use in equines.
A 2012 study, conducted through the Department of Veterinary Clinical Sciences, Equine Health Studies Program of School of Veterinary Medicine at Louisiana State University, and SmartPill Corp., Buffalo, New York, evaluated the wireless ambulatory capsule through the GI tracts of ponies.
The capsule measures pressure, pH and temperature to access gastrointestinal motility as it moves through the GI tract, according to LSU’s Frank Andrews, DVM, MS, Dipl. ACVIM.
Dr. Andrews is board certified in large animal internal medicine. Andrews said the SmartPill traveled successfully through the test ponies guts, though the study concluded that gastric emptying time is too variable and transit time too unpredictable for extensive use in equines at this time.
(Source: STOKES, A. M., LAVIE, N. L., KEOWEN, M. L., GASCHEN, L., GASCHEN, F. P., BARTHEL, D. and ANDREWS, F. M. (2012), Evaluation of a wireless ambulatory capsule (SmartPill®) to measure gastrointestinal tract pH, luminal pressure and temperature, and transit time in ponies. Equine Veterinary Journal, 44: 482–486. doi: 10.1111/j.2042-3306.2011.00533.x )
Blake says a major advancement in helping the small equine practice or clinic is the introduction of a mobile MRI service.
"With its own MRI equipment in a mobile unit, this service helps to overcome the cost hurdles small practices may face in purchasing expensive equipment, as well as building and staffing their own facilities,” she says.
Nuclear scintigraphy—bone scans—involve injecting a horse with radioisotopes that are absorbed by bony and injured areas. A gamma camera is then used to identify areas of of increased radioisotope uptake.
"The bone scans help us find active areas of bone inflammation, even at multiple sites,” she says.
"The biggest advance in technology is still the cell phone,” says Blikslager, "allowing better communication between veterinarians and their clients, particularly with the increasing use of texts.”
He says practitioners rely on their phones for taking photographs, sending images for second opinions, and image capture for Coggins tests. Apps for drug formularies, metric conversions, flashlights and GPS are easily downloaded.
Phones have become an integral part of almost every practice.
"It has gotten to the point that I don’t remember how we operated without them,” Blikslager says.
Blake says tablets and cell phones give veterinarians portable opportunities to record lameness exams, both initial exam to progressive.
"New programs for digital cameras and smartphones bring lameness diagnosis to an art form,” she says. "We can show and send before and after images of excellent quality.”
Equine thermal imaging is a non-invasive diagnostic tool that uses a lightweight, durable, point-and-shoot camera and computer software to detect minute differences in the horse’s thermal and neural condition.
"This modality is great for highlighting active bone inflammation and mild muscle injuries,” Blake says.
A digital infrared thermal imaging camera not only helps detect injuries before there are visible signs, she says, it is helpful in monitoring recovery.
By accurately measuring temperature of the injured area that is displayed in real time on an LCD screen, the high-resolution instrument provides the ability to scan the horse’s entire body for hot spots—inflammation or swelling—or cold spots—nerve damage or scar tissue.
All of this technology, though, does not make obsolete ultrasound and X-ray equipment that has long been a basic veterinary diagnostic tool, Blake says.
However, advancements in digital radiography and ultrasound provide an opportunity to make diagnoses faster and more accurately. And affordability and portability, she says, have made such equipment part of nearly every mobile equine practice.