Transdermal carbon dioxide may accelerate hoof growth in healthy, sound horses in a short-term, randomized, controlled clinical trial.

Abstract

Objective: Slow hoof growth poses a clinical challenge when hoof wear exceeds natural growth. Many treatment options have been reported without controlled prospective trials. The objective of this study was to evaluate the effect of transdermal CO2 on the rate of growth in treated hooves.

Methods: A prospective, randomized, blinded, crossover study of 14 Warmblood mares. Horses were randomly assigned a number and allocated for treatment of the front feet with room air or CO2 for 30 minutes 3 times per week, and groups were switched after 5 weeks. Hoof growth was measured on the dorsal midline and the quarters of each front foot. The distance from coronary band to lines made on the hoof wall was measured at the beginning, middle, and end of the study. The percentage of change in length at each location relative to baseline was evaluated at 5 weeks and 10 weeks using nonparametric analyses.

Results: All treatments were successfully administered. The left front medial (P = .028) and right front lateral (P = .03) sites of the CO2-treated hooves increased growth compared to the room air group at the 5-week point.

Conclusions: The results of this study suggest that repeated, noninvasive transdermal application of CO2 may accelerate hoof growth in normal horses over a 5-week treatment period.

Clinical relevance: This study suggests that transdermal CO2 may increase the rate of hoof growth in normal horses. The mechanism of action of this treatment is unclear, and further studies are required to fully elucidate the potential effects.