Can Carbon Dioxide Stimulate Hoof Growth in Horses?

Speed of hoof growth depends on many factors, including nutrition, activity level, and environmental conditions. In addition to biotin supplementation, research suggests that topical delivery of carbon dioxide may accelerate hoof growth in healthy horses.^*

Slow hoof growth may result in loss of use or decreased welfare as result of pain emanating from thin soles and from inability to fasten a shoe because of insufficient hoof wall. While manufacturers often claim that their products accelerate hoof growth, few studies support these claims, other than biotin.

“While poor-quality hooves respond to supplementation with therapeutic amounts of biotin by increasing hoof wall strength, improving hoof growth rate was only observed in some, but not all, studies,” said Kathleen Crandell, Ph.D., a Kentucky Equine Research nutritionist. “Improvements in hoof quality will be evident anywhere from 8 to 15 months after supplementation begins, depending on growth rate. Bio-Bloom PS (Bio-Bloom HF in Australia) supplies biotin as well as other hoof-building nutrients in therapeutic amounts.”

In humans, transcutaneous (across the skin) application of carbon dioxide demonstrated some benefits in wound healing. The potential mode of action remains unknown but may involve increasing oxygen delivery to the tissues by carbon dioxide exchange with the blood vessels, known as the Bohr effect.

To determine if transdermal carbon dioxide could increase forelimb hoof growth, 14 healthy Warmblood mares were recruited. Mares were barefoot for three months prior to commencement of the study, maintained without shoes, and were not trimmed during the study. Three small horizontal lines were created with a rotary cutting tool 1 cm from the coronary band on the medial, lateral, and middle aspects of the hoof. All horses had their hooves dampened and a bag placed over the forelimb. In the control group, the bags were inflated with room air, whereas the treatment group bags were inflated with medical grade, humidified carbon dioxide. Both treatments were applied for 30 minutes three times a week for five weeks.

“Hoof growth was significantly increased in the left front medial quarter and the right front lateral quarter in horses treated with carbon dioxide after five weeks,” Crandell said.

This pilot study supported hoof growth, although inconsistent, and suggests that transdermal carbon dioxide, a noninvasive and technically feasible treatment, is worth additional research. If additional positive results are achieved, this could be a much-needed treatment method for horses with poor hoof quality or abnormal metabolic status.

^*Rudnick, M.J., H.L. Stewart, M.D. Burleson, and D. Levine. 2024. Transdermal carbon dioxide may accelerate hoof growth in healthy, sound horses in a short-term, randomized, controlled clinical trial. American Journal of Veterinary Research:0161.