Evaluating an equine athlete who is underperforming or acting out of character can be incredibly frustrating. When standard flexion tests, nerve blocks, and routine X-rays yield no clear answers, it may be time to look deeper. Nuclear scintigraphy, commonly known as bone scan, offers a highly sensitive diagnostic tool to locate potential sources of pain in the horse's body.

Unlike traditional imaging, such as digital radiography or ultrasound, which reveal structural damage that has already occurred, a bone scan is a functional imaging modality. By tracking cellular-level changes and bone remodeling before structural damage is visible on an X-ray, this technology acts as a roadmap that can show veterinarians where a horse is hurting.

Solving the Sports Medicine Puzzle

In equine sports medicine, issues rarely affect just a single leg. Performance horses frequently experience multi-limb lameness or compensatory soreness, where pain in one area causes them to overload another.

A bone scan evaluates the entire skeleton in a single session, pinpointing active areas of bone remodeling. This holistic view allows sports medicine specialists to identify hidden stress fractures, injured tendon and ligament attachments, early arthritis, or active joint inflammation through the whole body, creating a more accurate and comprehensive picture of the athlete. This allows for a comprehensive treatment and rehabilitation plan

Uncovering the Roots of Poor Performance

When a horse begins failing to hit its marks - such as refusing to jump, inconsistent lead changes, or losing power from the hind end - the cause is frequently orthopedic. Nuclear scintigraphy excels at scanning areas of the body that are notoriously difficult to reach with standard X-ray or ultrasound equipment. It is highly effective for identifying deep-seated orthopedic issues, including:

• The pelvis and hip joints
• The sacroiliac (SI) region
• The spine (detecting kissing spines or articular process osteoarthritis)
• Shoulder and elbow joints

Linking Pain to Behavioral Concerns

Horses communicate physical discomfort through behavior. When a previously willing horse begins resisting training, a medical issue is often the root cause. Behavioral changes that warrant a dynamic look via nuclear scintigraphy include:

• Uncharacteristic pinning of ears, biting, or kicking when being saddled or girthed.
• Rearing, bucking, or bolting
• Resistance to bending, head tossing, or persistent sourness during work.

Musculoskeletal problems found on bone scan frequently confirm a "bad attitude" is a clinical response to chronic, hidden pain.

Nuclear scintigraphy is a powerful diagnostic tool enhancing the ability of veterinarians to localize areas of stress, arthritis, fractures and other musculoskeletal injuries. It allows us to perform evaluations from a different vantage. Once an area of interest is discovered with bone scan, the information my lead to further diagnostics such as nerve or joint blocks, radiographs, ultrasound… Occasionally a scan my not show a specific diagnosis. This can be useful as well by ruling out areas of question. If you have questions, please contact us to discuss whether a comprehensive nuclear scintigraphy evaluation is the right step for your athlete

Case Example:

A warmblood show hunter presented with an acute onset of left forelimb lameness. Over the following weeks, the lameness progressively worsened, and a lameness examination was scheduled.

On examination, he exhibited a pronounced head bob and reduced limb extension in the left forelimb in both directions, with the lameness more severe when circled to the right. Diagnostic nerve blocks were performed to localize the source of pain. Sequential blocks, beginning at the foot and progressing proximally to the upper cannon bone,

The shoulder joint was injected with a regenerative product. Over the following three weeks, the horse improved by approximately 50%. At that time, nuclear scintigraphy (bone scan) was performed.

The bone scan revealed moderate radioisotope uptake over the point of the shoulder, which is consistent with either direct trauma to the area or secondary involvement from bicipital bursitis. A diagnostic block of the left bicipital bursa was positive. Radiographs and ultrasound of the shoulder were then performed to further evaluate the area. The bursa was treated with injection and extracorporeal shockwave therapy. The horse responded well to treatment, completed a progressive return-to-work program, and has returned to his prior level of use.

In this case, bone scan helped define the type of injury and further localize the affected area following initial diagnostics and treatment. It is particularly valuable for identifying bone injury that other diagnostic modalities may not detect.