Injury to the superficial digital flexor tendon (SDFT) can result in long-term lameness and a slow recovery. An Iraqi study compared DMSO to MSM when applied topically to the skin over an injured tendon [Ahmad, F.; Akbar, H.; Hayar, MA.; et al. The role of DMSO and MSM in treatment of tendinopathies affection in equine: A comparative study. Iraqi Journal of Veterinary Sciences 2022, vol. 36, no. 4, pp. 861-868; doi:10.33899/IJVS.2022.132428.2088].
Ten polo horses aged 5-15 years with chronic superficial digital flexor tendinitis participated in the study. Treatment was applied once weekly for seven weeks. A group of five horses received treatment of their SDFT injury using 60 ml of topical 90% DMSO aqueous solution. The other five received treatment of 60 ml of topical 90% MSM aqueous solution. The treatments were applied to a shaved area of the SDFT injury and bandaged for 12 hours.
Researchers assessed lameness and pain scores. They performed ultrasonic imaging of fiber alignment and echogenicity on days 0, 21 and 42.
The authors conclude that topical DMSO has a more significant effect on pain severity and lameness compared to topical MSM. In addition, ultrasound parameters—fiber alignment and echogenicity—improved more by day 42 with DMSO compared to MSM.