Short-term effects of pulsed electromagnetic field therapy on subjective flexion-associated lameness responses and circulating cytokines in horses with distal tarsal osteoarthritis.

BACKGROUND

Pulsed electromagnetic field (PEMF) therapy is commonly used in equine sports medicine for its proposed anti-inflammatory effects; however, limited controlled studies have evaluated its physiologic effects in horses.

AIMS/

OBJECTIVES

The objective of this study was to investigate the effects of PEMF therapy on flexion-induced lameness and circulating cytokines in horses with radiographic evidence of distal tarsal osteoarthritis.

METHODS

Six mares were enrolled in a repeated-measures crossover design in which each horse served as its own control. Horses were evaluated at baseline (sham PEMF) and at 1 hour, 1 day, and 1 week following a single PEMF treatment. Lameness was assessed subjectively by a blinded veterinarian following standardized tarsal flexion testing and objectively using an inertial sensor-based gait analysis system (Lameness Locator®, Equinosis). Serum cytokines were quantified using a multiplex immunoassay.

RESULTS

PEMF treatment reduced the subjective flexion-induced lameness response 1 hour following treatment (1.83±0.17 vs. 1.00±0.26; p=0.03); however, no differences were identified at 1 day or 1 week. Objective gait asymmetry was not altered by PEMF treatment (p=0.67). Circulating IFNγ concentrations decreased 1 hour following PEMF exposure (1319.1±373.9 pg/mL vs. 863.1±227.1 pg/mL; p=0.05), while other cytokines were unchanged.

CONCLUSION

These findings suggest PEMF therapy may induce transient effects on inflammatory signaling and subjective pain responses in horses with distal tarsal osteoarthritis, although objective gait asymmetry remained unchanged.