180 Effect of leg wraps on skin temperature in exercising horses

Abstract

Tendon or ligament injuries are common in performance horses and have a negative impact on training time and economics in all equestrian disciplines. There are some factors that increase the risk of tendon and ligament injury including fitness level, overexertion, and tendon core temperature. In vitro studies have shown fibroblast death at tendon core temperatures of 43° to 48°C, suggesting that repeated hyperthermic events may predispose the horse to tendon or ligament injury. The distal limb of the horse houses tendons and ligaments only, and is often covered in boots or polo wraps during exercise to protect the limb from trauma. Previous studies of exercising horses have compared distal limb skin temperature under solid boots, perforated boots, and polo wraps, and found that increased airflow is important to reduce skin temperature and likely tendon core temperature. Currently on the market are several brands of polo wraps that claim to promote airflow and keep the limb cooler during exercise than traditional coverings. The objective of this study was to investigate this claim and compare the distal limb skin temperature under a traditional pair and 2 brands of cooling polo wraps during and after exercise. Using a HOBO TidbiT MX Temperature Data Logger taped on the skin halfway between the ergot and accessory carpal bone, a total of 5horses were used to test a different covering each day: traditional fleece polo wrap, cooling wrap 1, and cooling wrap 2. The temperature under the wraps was recorded during exercise and for an additional 5 min afterward at rest. For all 3 treatment conditions, the median was used as the measure of center for the distributions of average temperature change because the distributions for the cooling wraps were highly right skewed. Because of the small sample size, a Friedman test (P = .05) was conducted to determine if there was a significant difference in the average heat buildup between the 3 treatments. The median of the average temperature change was 4.24°C for the regular fleece polo wrap, 3.50°C for cooling wrap 1 and 2.70°C for cooling wrap 2. There were no statistically significant differences found in the distributions of average temperature across the 3 treatments (P = 0.247). However, the data did show a trend of lower average temperature under the cooling wraps compared with the traditional fleece wraps. These results prompt further study of larger sample size, time to plateau and cool down under the wraps, and temperatures under more rigorous exercise to fully evaluate the difference between treatments.