Diagnosing Arthritis in Horses with Acoustic Emissions

Painful deterioration of joint cartilage, called osteoarthritis (OA), plagues the joints located in the lower limbs of athletic horses. No cure for OA has been uncovered, despite its prevalence among horses. Further, diagnosing OA early in the course of disease remains challenging.

“Ruling out other causes of lameness and obtaining a diagnosis of OA early in the disease process would allow veterinarians to select the best treatment plan to maximize joint health,” said Catherine Whitehouse, a Kentucky Equine Research nutrition advisor.

“Most currently available diagnostic imaging techniques do not allow veterinarians to see cartilage, though. Exceptions include arthroscopy and magnetic resonance imaging, but these have several downsides, such as needing to place the horse under general anesthesia,” she added.

In a recent study*, veterinary researchers from Finland explored a novel method of imaging cartilage using acoustic emissions.

“Acoustic emissions are a type of energy wave generated from a redistribution of stress in a material. Changes in pressure, load, or temperature, for example, induce the release of these emissions in the form of stress waves. Those waves rise to the surface of the material in question where they are recorded by sensors,” Whitehouse explained.

This technology is being used in human medicine to assess ligament damage, bone fractures, and integrity of hip implants, to name only a few applications.

In the inaugural study of acoustic emissions in horses, the researchers obtained 16 limbs (from horses euthanized for reasons not related to this study) and artificially created OA in eight joints by rubbing cartilage with sandpaper to mimic the progressive damage to joints in naturally occurring OA. Eight limbs were left intact. Acoustic emission signals were subsequently obtained from each group of limbs and compared.

Acoustic emissions signals were increased in joints with artificial OA. Further, the more advanced the OA (i.e., increased application of sandpaper to cartilage), the greater increase in signals.

“The consistent results for such simulated condition suggests there is potential for this method in the diagnosis of OA,” concluded the authors.

Well-formulated supplements, such as Synovate HA, KER-Flex, and EO-3 support joint health. Many horsemen use these products prophylactically, or before any sign of joint damage appears, in an attempt to protect cartilage and to stave off OA and other problems.

*Shakya, B.R., A. Tiulpin, S Saarakkala, et al. Detection of experimental cartilage damage with acoustic emissions technique: An in vitro equine study. Equine Veterinary Journal. In press.