A comparison of the effects of two volumes of local analgesic solution in the distal interphalangeal joint of horses with lameness caused by solar toe or solar heel pain.

This study investigated the effect of two different volumes of local analgesia on horses suffering from lameness due to pain in their hooves. The study found that pain relief was more effective when a larger volume of analgesia was administered and that the location of the hoof pain also impacted the effectiveness of the treatment.

Study Design and Methodology

• The study involved seven horses suffering from solar pain in either the dorsal or palmar aspect of the foot. The pain was artificially induced by the use of set-screws inserted into a custom-made shoe.
• The effectiveness of two volumes of local analgesic solution, 6 ml, and 10 ml, was tested. These were administered into the distal interphalangeal (DIP) joint of the horses.
• The horses were videotaped both before and after the set-screws were applied, and again after administration of the local analgesic solution. This allowed researchers to monitor and evaluate the changes in the horses’ trotting patterns.

Results and Findings

• The results were quantified by assigning lameness scores based on the examination of the videotaped gaits.
• Horses that had set-screws applied to the angles of the sole and received 10 ml of local analgesic solution showed significantly lower lameness scores. However, this was not the case when 6 ml of local analgesic was administered.
• All horses that had set-screws inserted in the dorsal margin of the sole, regardless of the volume of analgesic solution given, exhibited significantly lower lameness scores.
• The study found that analgesia of the DIP joint was less effective in desensitising the angles of the sole compared to the dorsal margin of the sole, with 10 ml of local analgesic solution being more effective than 6 ml in desensitising these regions.

Conclusion

• This research concluded that the response of horses with solar pain to a local analgesic solution in the DIP joint is influenced by the volume of the solution administered and the region of the sole affected by pain.
• This implies that for a more effective management of lameness in horses due to solar pain, significant consideration should be given to the location of the pain and the volume of the analgesic solution used.