Remember that tricky thousand-piece jigsaw puzzle, probably of a herd of horses, you put together as a kid? Now consider how much harder it would have been to assemble the puzzle upside down, with no picture to guide you.
That is sometimes the difference between diagnosing lameness in a horse’s lower limb and pinpointing a problem higher up in his body. Once your veterinarian rules out anything from the foot past the knee, the diagnostic difficulty level can soar.
Kirste Timm, DVM, of California Equine Sports Medicine, in Santa Ynez, and Carrie Schlachter, VMD, of Circle Oak Equine, in Petaluma, California, see many sport horses in their practices. They described lower-limb lameness in last month’s issue and will characterize lameness stemming from the upper body in this article.
“These lamenesses are often not overt and are more performance issues,” says Timm. “Also, many different issues in the upper body can have the same presentation,” or on the surface a upper-body injury can look just like a lower-limb lameness.
Fortunately, upper-body lamenesses are less common than those affecting the limbs, says Schlachter, but that means it’s especially important that you consult a veterinarian who has experience diagnosing them.
Another challenge with diagnosing these problems is the sheer mass of a horse’s body. Upper-limb muscles reduce the image quality of radiographs and ultrasound, says Schlachter. And while MRIs and CT scans can be very useful for diagnosing lower-limb lameness, a horse’s upper body parts are too big to fit into current models of those machines.
Occasionally, an lameness-inciting incident might point straight to an upper-body injury. For example, says Timm, if a horse gets cast in his stall or falls and becomes lame as a result, a veterinarian might zero in immediately on the neck or vertebrae. A horse that refuses to extend his shoulder while exercising might lead the veterinarian to look at the shoulder and lower neck. If a horse cannot extend his elbow and locks his forelimb, he could have a fractured elbow.
But, for the most part, successfully diagnosing a lameness stemming from the upper body can be a longer and more complex process than finding a problem in the lower leg.
Where to Start
Both of our sources explain that unless an incident like the ones described points quickly to the upper body, veterinarians begin their search for lameness cause at the foot and work upward, just as they would with a lower-limb lameness. Using palpation, hoof testers, and nerve blocks, they can rule out the usual suspects of foot, fetlock, and knee problems and start to move toward the upper legs, shoulders, stifles, back, and neck.
Because upper-body issues frequently show up as subtle performance problems, it is important for a veterinarian to get a history on the horse from the owner or rider and watch him move with and without a rider. The more information you can provide to your veterinarian, the better your chances are for a swift and accurate diagnosis.
Palpation generates less sensitive and specific reactions in the upper body than it does with a limb, but that doesn’t mean this lameness exam step cannot yield some answers. Timm says back palpation, in particular, might generate significant reactivity warranting further investigation.
“The limitation in external palpation is that by the time the nerves reach the outside of the body (where we palpate), they may well have traveled pretty far from the actual source of the issue,” and the horse might not appear as sensitive as he would be at the site of the injury, says Schlachter. “So you have to be careful with your interpretation of the results of your exam.”
Flexion and range-of-motion tests, such as bending the neck in both directions, can also help the veterinarian pinpoint the area of concern.
Chiropractic training can help a veterinarian target likely problem areas for a diagnosis and then treatment, says Schlachter.
“Lamenesses due to upper-body issues tend to be more chronic and insidious and, therefore, harder to ‘treat and cure,’ similar to back issues in people,” Timm says.
Thus, just as some people can improve with periodic chiropractic care, some horses experiencing chronic upper-body problems, once diagnosed, can benefit from it as well, she notes.
Compounding the difficulty of diagnosing equine upper-body issues is the possibility that a problem stems from more than one source, especially in older animals.
“A horse may have lower cervical (neck) issues and feet issues, or lower cervical issues and back issues,” says Timm. “It’s often hard to know if one is causing the other or if it’s due to age and repeated stress on multiple areas.”
Sometimes multiple problems crop up simply because of how the limb is constructed. For example, Timm says horses can develop sacroiliac (the joint connecting the pelvis and spine) soreness, stifle soreness, and hind-suspensory soreness—all hind limb problems that work together and build on one other as multiple causes of lameness.
Schlachter, who consults on many cases after a horse’s own veterinarian has made an initial diagnosis, recalls a situation where multiple causes of lameness complicated the diagnostic process.
A jumper appeared to have acute back pain after a competition, showing soreness in his saddle and thoracolumbar area (the region of the vertebral column stretching from the upper trunk to in front of the pelvis). The horse improved after two rounds of acupuncture and chiropractic care targeting the back soreness, but then he developed lameness in the lower right front leg.
“I’m sure that is what caused the back pain to start with,” says Schlachter, who believes the lower-limb lameness was so very subtle initially that the horse felt and compensated for it only when performing tasks such as cantering or landing from jumps. Once the lameness became evident, she turned her focus to treating the right front limb, and subsequently the back pain resolved.
Common Body Problems
While upper-body issues can stem from numerous problems, as we’ve seen with the aforementioned case example, veterinarians see a few causes more frequently than others.
Muscle soreness, if you’re lucky, is a simple cause of your horse’s body lameness. Like humans, horses can pull, overstretch, or tear muscles. Sometimes all a horse needs is a little time off.
“Muscle soreness is easily dealt most of the time with medication, management changes, or massage—or in my hands with chiropractic and/or acupuncture,” says Schlachter.
Owners and veterinarians must be careful, however, that muscle soreness is not masking a fracture.
“A muscle tear is usually associated with pretty severe swelling in the area of injury,” says Schlachter. “A severe muscle tear often presents similarly to a bony fracture in the upper body. Careful palpation (so as to catch subtle details) and aggressive (ultrasound and radiograph) imaging can often help a veterinarian discern a torn muscle from a broken bone pretty quickly.”
Osteoarthritis, especially in aging horses, can develop almost anywhere in the body and limbs. Timm says osteoarthritis in the cervical vertebrae can appear subtly, with the horse showing discomfort in his head and neck carriage. He might have difficulty performing or resist lateral and/or ventral flexion under saddle and could have areas of muscle atrophy (wasting).
Timm recalls an equitation horse that displayed intermittent forelimb lameness under saddle after jumping and when he collected or elevated his neck. While at first it looked like a foot problem (and the gelding did have a history of foot issues), nuclear scintigraphy (bone scan) ultimately revealed osteoarthritis in the lower neck. Timm was then able to manage the lameness using ultrasound-guided injection of the small articular joints in the neck.
Back problems can originate from something as acute as poor saddle fit to one as chronic as kissing spines. The latter is also called overriding dorsal spinous processes and occurs when the bony ridges on the top of the spine grate together, or “kiss,” causing proliferative new bone development. Given that the saddle sits over much of this area, kissing spines can certainly cause a very painful or sore back in ridden horses, but Timm says it can also result in hind-limb lameness. Similar to humans with back problems, horses might adjust their gait to compensate for their back pain.
Stifle and shoulder problems are among the most common upper-body issues, said Schlachter.
“Stifle issues are often characterized by a notable level of instability in a hind limb,” says Schlachter. She adds that horses with stifle pain might demonstrate a twisting motion at the walk.
“Shoulder issues are often characterized by a shortened cranial phase of the stride at the trot (the portion of the stride where the forelimb reaches forward),” Schlachter says. This shows up best when the horse moves in a circle with the suspect limb on the outside of the circle.
Fractures do occur in such areas as the pelvis, back, and neck, but these are less common than other upper-body issues, says Schlachter. Hind-end lameness can be a sign of pelvic and sacroiliac issues.
These types of hind-end lamenesses might show up simply as performance issues, says Timm. A horse might resist going forward or show a reluctance to go down hills on trails, she adds.
Because these bony areas lie under muscle, such lamenesses can be difficult to diagnose. Researchers have shown that microfractures can start in the pelvis, just as they can in other bones. Veterinarians can use nuclear scintigraphy to diagnose the beginnings of pelvic fractures in racehorses, allowing them to prescribe rest for healing and help trainers avoid what could eventually become catastrophic injuries.
Wobbler syndrome (cervical vertebral stenotic myelopathy or cervical vertebral compressive myelopathy) is perhaps one of the most intricate equine body lamenesses, as it affects both the neurologic and musculoskeletal systems.
Wobblers show neurologic signs such as abnormal gait of the hind or forelimbs, depending on the location of the lesions between the neck vertebrae, says Timm. “The horse may also have a history of falling in turnout or under saddle and may seem to trip more than usual.”
Wobbler syndrome is so very serious that in the past many veterinarians recommended euthanasia. But treatment methods have advanced, so veterinarians can manage some affected individuals safely.
As diagnostic equipment continues to improve, veterinarians will likely be able to diagnose upper-body issues more quickly and easily. Schlachter notes that wireless kinematic gait analysis systems might ultimately prove helpful.
“The newer systems can assess back movement as well as lower-limb lameness and can often point you in the right direction sooner,” she says. “There is still a lot of research that needs to be done to assess how and when we should use this (diagnostic) modality in horses.”
Lamenesses that stem from the upper body can be difficult to diagnose, often requiring multiple exams to pinpoint a specific problem. Lower-limb lamenesses can complicate the diagnostic picture. Much of the diagnostic equipment available cannot be used on a horse’s upper body, so veterinarians must rely on diagnostic clues from other body parts and methods. But with the trust and cooperation of the rider or owner, as well as advances in technology, veterinarians can treat and/or manage more of these issues successfully.