Effects of topical application of pirfenidone ointment on thermoplasty-induced acute lameness in a double-blind and acute and chronic lameness of musculoskeletal origin in an open multi-centered field trial in horses.

The research study explores the effectiveness of using pirfenidone ointment as a treatment for acute lameness in horses caused by thermoplasty or musculoskeletal disorders. Topical application of the ointment significantly reduced swelling and improved flexibility, suggesting pirfenidone could be a promising therapeutic solution to manage acute inflammation associated with these conditions.

Objective of the Study

• The main goal of this research was to determine the effectiveness of pirfenidone ointment when applied topically for treating acute lameness in horses. This condition was either induced through thermoplasty or arose due to acute and chronic musculoskeletal disorders.

Methodology

• Thermoplasty was conducted on the inner forelegs of horses under anesthesia. Post-thermoplasty, a placebo or a 10% pirfenidone ointment was applied topically three times daily for a duration of one week.
• For horses suffering from acute and chronic musculoskeletal lameness, the pirfenidone ointment was applied one to three times a day for a period of 7 to 10 days, with treatment extended for another 20 to 30 days.

Key Findings

• Notable swelling was observed around the thermoplasty site 24 hours after the procedure. Applying pirfenidone ointment topically resulted in a significant reduction in the measurements of swelling on the 5th, 6th and 7th day post-procedure compared to the placebo ointment.
• For cases of acute leg lameness arising from musculoskeletal disorders, treatment with pirfenidone ointment made noticeable improvements in terms of reducing swelling, relieving pain, and increasing the degree of joint flexibility post-treatment.
• However, the ointment had minimal effects on chronic lameness cases, except for improving the flexibility at the second-exam interval.

Conclusion

• The study concludes that the topical application of pirfenidone is an effective therapeutic intervention for treating acute lameness in horses whether caused by thermoplasty or different types of musculoskeletal disorders.
• This ointment potentially offers a new treatment approach to manage acute inflammation, a significant component of lameness.