Comparison of Postexercise Cooling Methods in Working Dogs.

BACKGROUND: Overheating is a common form of injury in working dogs. The purpose of this study was to evaluate the relative efficacy of three postexercise cooling methods in dogs with exercise-induced heat stress.

METHODS: Nine athletically conditioned dogs were exercised at 10kph for 15 minutes on a treadmill in a hot environmental chamber (30°C) three times on separate days. After exercise, the dogs were cooled using one of three methods: natural cooling, cooling on a 4°C cooling mat, and partial immersion in a 30°C water bath for 5 minutes.

RESULTS: Time-weighted heat stress was lower for immersion cooling compared with the cooling mat and the control. The mean time required to lower gastrointestinal temperature to 39°C was 16 minutes for immersion cooling, 36 minutes for the cooling mat, and 48 minutes for control cooling.

CONCLUSION: Water immersion decreased postexercise, time-weighted heat stress in dogs and provided the most rapid cooling of the three methods evaluated, even with the water being as warm as the ambient conditions. The cooling mat was superior to cooling using only fans, but not as effective as immersion. The placement of simple water troughs in working- dog training areas, along with specific protocols for their use, is recommended to reduce the occurrence of heat injury in dogs and improve the treatment of overheated dogs.