Doppler Ultrasonography for Monitoring Tendonitis in Horses

Researchers are brightening up the field of monitoring equine tendonitis healing: Recent study results suggest that the colors displayed by Doppler ultrasonography could help veterinarians better follow the healing processes of certain conditions, like tendonitis.

“The color represents the blood flow,” said Daiki Murata, DVM, PhD candidate, researcher in the Department of Veterinary Clinical Science at Kagoshima University in Kagoshima, Japan. And blood flow can provide insight into the injured tendon's healing status in a way that standard ultrasound—what Murata calls the current “gold standard” in tendonitis diagnostics—cannot.

Daiki and colleagues Kazuhiro Misumi, PhD, and Makoto Fujiki, PhD, evaluated 10 Thoroughbred racehorses with confirmed superficial digital flexor tendon injuries. The different rates of blood flow in the injured tendons caused different kinds of “color activity”—rhythmic blinking of small signals, pulsating expanded dots, or dynamic streams. The researchers assigned Grades 1, 2, or 3 to these different color activities, respectively. The color activity does not indicate the degree of injury; rather, it is representative of the amount of blood flow in a certain area, which can help veterinarians determine the state of healing.

This graded color activity offers a specific advantage over gray-scale ultrasound, Murata explained. Traditional ultrasounds have “questionable power to discriminate inflammatory and fragile granulation tissue from scar tissue,” he said. But the blood flow, as detected by the color ultrasound, makes this discrimination easy.

What that means for horse owners and riders is a better picture into how the tendon is healing. Practically speaking, it means clinicians can better determine whether horses are ready to start light or moderate exercise again, whether more rest is necessary, or whether other treatment options should be considered, Murata said.

It’s important to note, of course, that the color seen on the ultrasound does not represent any real colors in the horse’s tendon. The equipment creates the colors to represent blood flow activity, and the different colors and movement patterns represent the kind of flow and the intensity.

While the technology is still new, good-quality color ultrasound machines are nonetheless affordable for many equine veterinarians, he added. “Although the machine we used was very expensive (¥7,000,000, or $72,000), you can now buy and use a better and less expensive machine than the one we used,” he said.

The study, "A preliminary study of diagnostic color Doppler ultrasonography in equine superficial digital flexor tendonitis," was published in the Journal of Veterinary Medical Science

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.