Effects of intrabursal administration of botulinum toxin type B on lameness in horses with degenerative injury to the podotrochlear apparatus.

The research paper investigated the safety and short-term benefits of using botulinum toxin type B injections to improve lameness in horses suffering from degenerative damage to the podotrochlear apparatus. The results showed temporary relief in all tested cases, though some degree of lameness persisted after the study.

Methods and Participants

• Ten Quarter Horses with degenerative injuries to the podotrochlear apparatus (PA), the soft tissue and bony structures in the hooves, were chosen.
• After confirming the injuries through diagnostic analgesia and imaging, botulinum toxin type B (BTXB) was administered directly to the podotrochlear (also known as navicular) bursa of each horse at a dosage of 3.8 to 4.5 U/kg. The navicular bursa is a small fluid-filled sac that allows for smooth movement between the tendons and the bones in the hoof.
• Out of the ten horses, three were specifically used for a safety evaluation of the procedure.
• The remaining seven horses had their progress documented through video recordings of lameness evaluations taken at baseline (5 days before BTXB administration), and then again at 7 and 14 days after treatment. One horse had to be removed from the study after the 8th day.

Data Analysis

• Three investigators, blinded to the specifics of which forelimbs were treated and at what time points, reviewed the video recordings. They independently assessed and graded the lameness of both forelimbs for each horse.

Results

• The study found that all horses experienced an improvement in lameness at either one, or both, of the posts-treatment checkpoints.
• However, all horses still exhibited some degree of lameness by the end of the study period.
• Two horses showed a temporary increase in lameness between 48 to 72 hours post-treatment, but these symptoms resolved on their own without the need for additional intervention.

Conclusions

• The research concluded that intrabursal injection of BTXB provided temporary relief from chronic lameness in horses suffering from degenerative injuries to the PA, without causing significant short-term adverse effects.
• However, the researchers also call for further study into the potential use of BTXB for horses with similar conditions due to the persistent lameness at the end of the study as well as the transient increase in lameness experienced by a couple of horses.