Equine Orthopedic Ultrasound for Lameness in Horses

Ultrasound machines are transportable and can be used in a variety of locations, making in-the-field work possible for some cases of lameness where a horse may not be able to be transported to a veterinary hospital. However, ultrasound images can be technically difficult to obtain and interpret – this is especially true with orthopedic ultrasound. Because of these limitations, a very controlled environment, like our hospital or a stable, is best to ensure accurate results. When it comes to reading the results of an orthopedic ultrasound for horses, real-time interpretation is typically best, but in some cases, images can be saved and interpreted by veterinarians or radiologists at a later date.

Ultrasound vs. X-Ray for Identifying Lameness in Horses

Ultrasound is the preferred imaging method used for diagnosing and identifying lameness in horses due to its superior ability to visualize soft tissue structures, like tendons, ligaments, and cartilage, that are most commonly associated with the injuries leading to lameness.

Because of this, ultrasound is superior to X-rays. X-rays are the best for examining bones. Because lameness can stem from many causes, I often use both ultrasound and X-rays to get a complete picture of an injury.

Why Catching Lameness in Horses Early Is So Crucial

Equine tendons and ligaments are designed to handle a lot of stress. However, once a ligament is injured, it is weaker than before, even if it has healed. When there is an extended period of time between an initial injury and when treatment and therapy begin, more unorganized scar tissue will develop during healing. This unorganized scar tissue leads to weaker tendons and ligaments after healing.

Our goal for therapy is to obtain good quality healing that is as organized as possible, thus it is as strong as possible, so that the horse can return to athletic activity without re-injury.

Injuries that Can Be Diagnosed with Ultrasounds for Horses

Lameness in horses can stem from many causes and can be a result of a number of orthopedic injuries. The most common injuries I use ultrasound to diagnose are injuries to the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and suspensory ligament. These tendons and ligaments run down the back of the horse's limb. The flexor tendons attach to bones in the distal limb and muscles in the proximal limb. The muscles pull the limb up via the flexor tendon's attachment to the bones. This allows the horse to walk, run, and perform athletically. Injury to either the DDFT or the SDFT can be career-ending or even life-threatening.

The suspensory ligament attaches to bone below the knee in the front limb or below the hock in the hind limb. The suspensory ligament runs down from its attachment below the hock/knee to attach to the sesamoid bones in the fetlock. From there, the suspensory ligament runs forward, joining with the common digital extensor tendon and forming a cradle that supports the fetlock joint. The suspensory ligament supports the entire lower limb. Without this support, the horse is unable to move or perform properly. Like injury to the DDFT and SDFT, injuries to the suspensory ligament can be career-ending or even life-threatening.

How Ultrasound Findings Can Shape Recovery Plans

Recovering from a tendon or ligament injury can be a long process that often includes a rehabilitation program. When we utilize orthopedic ultrasound for horses in our Lameness Exams, we can create a tailored and effective recovery plan that suits the nature of the specific injury or area of pain. Ultrasound ultimately helps us characterize an injury so we know what structures are involved and how much damage is done. This information is used to help us estimate how long rehabilitation is required, and also helps us determine if we need adjunct therapy such as stem cell therapy, platelet-rich plasma therapy, and/or extracorporeal shock wave therapy.

As we progress through rehabilitation, ultrasound helps us determine when we can increase stress on the injured tendon or ligament. Before we increase the stress/activity, we re-ultrasound to be sure the injury has healed enough to handle the increased stress/activity. We do this approximately every 90 days. Ultimately, ultrasound can help us determine when the equine athlete is ready to go back to work.

Learn more about Equine Diagnostic Imaging at Conley and Koontz Equine Hospital

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