The role of DMSO and MSM in treatment of tendinopathies affection in equine: A comparative study

Superficial digital flexor tendon (SDFT) injury is a main cause of lameness in polo and racehorses inciting long-term lameness and recovery. This study aimed to compare the efficacy of topical dimethyl sulfoxide (DMSO) and Methylsulfonylmethane (MSM) on bowed tendons in horses. Ten client-owned injured horses, aged between 5-15 years with an average age of 8.5 years and weighing approximately 400-500 kg, suffering from chronic tendinitis were selected and allocated into two groups: group A (DMSO) and group B (MSM). The group A animals (n=5) were treated with 60 mL of topical 90% DMSO aqueous solution, while Group B animals (n=5) received 60 mL of topical 90% MSM aqueous solution on the bowed tendon at days 0, 7, 14, 21, 28, 35, and day 42. Clinical examinations were performed to evaluate the severity of pain and lameness grade. Ultrasound scans of the superficial digital flexor tendon were taken at days 0, 21, and day 42. Images were placed in numerical form, and the fiber alignment score of the fibers (FS) and the echogenicity score (ES) of the superficial digital flexor tendon at the maximum injury zone (MIZ) were recorded. Results showed that pain reduction and lameness significantly (P<0.05) reduced from 21d to 42d in the DMSO animals compared with the MSM animals. The echogenicity score didn’t differ between the two groups at 0d, 21d, and 42d (P>0.05) however, it was significantly declined in group A at 42d than 0d (P<0.05). Fiber alignment in group A was (P<0.01) reduced at 42d compared with group B. This study concluded that group A horses showed very effective and long-term improvements compared to the group B horses.