Modified ventilated capsule for the measurement of sweating rate in the exercising horse.

The research article discusses a modified method to measure the sweating rate in an exercising horse. Using a ventilated plastic capsule, the technique draws dry air over the horse’s skin and calculates the sweat rate based on humidity changes in the air.

Modification of Ventilated Capsule Technique

• The researchers modified a ventilated capsule technique to measure the sweating rate (SR) in exercising horses. A plastic capsule was securely attached to the horse’s coat and dry air was flowed over the skin.
• The computations of sweating rate were based on the changes in the absolute humidity. This is the volume of water in the air leaving the capsule compared to the air entering it.
• The measurements were repeated at two sites on the horse’s body: one 10 cm below the tuber sacrale, and the other above C4 on the neck. Comparisons were made to ensure repeatability and reliability of the measurements.

Flow Rate and Humidity Control

• The experiment also studied the influence of flow rate on the system’s response characteristics. The aim was to encourage rapid and complete evaporation of moisture from the enclosed coat area, which was achieved best by maintaining the air’s relative humidity below 15%.
• It was found that the desired humidity level is best achieved with a flow rate exceeding 35 liters per minute. Maintaining this flow rate ensured efficient evaporation and accurate SR calculations.

Results and Conclusions

• The results from the study revealed no significant difference between the measurements taken from two test sessions completed three days apart. This was in respect to both the right atrial temperature and sweating rate.
• The modified system for measuring SR in exercising horses portrayed quick response times and was capable of gauging a wide range of sweating rates accurately. The seal of the capsule remained intact throughout the exercise, and the capsule was removed without causing any harm to the horse’s coat.