Voluntary head dunking after exercise-induced hyperthermia rapidly reduces core body temperature in dogs

Abstract

OBJECTIVE To evaluate field-applicable cooling methods for treatment of exercise-induced hyperthermia in dogs. METHODS In this randomized, crossover study from June 27, 2023, to July 24, 2023, 12 working dogs exercised for 10 minutes until core body temperature reached 40.6 °C or above or ≥ 2 signs of heat stress were observed. Four different cooling protocols were evaluated: (1) neck chemical ice packs (2), (2) a wet (22 °C) neck towel, (3) wet (22 °C) axillae towels, or (4) voluntary head immersion (“dunking”) into (22°C) water. After intervention, dogs rested and were monitored for 40 minutes. RESULTS The dunking protocol, which included limited water ingestion, produced the lowest mean core temperature in the initial 5 minutes after exercise, in the subsequent 35 minutes during which dogs cooled to baseline temperature and was the only protocol to prevent the initial postexercise temperature rise. All methods resulted in return to baseline temperature. CONCLUSIONS Trained voluntary head dunk with limited water ingestion results in rapid cooling in field situations of exercise-induced hyperthermia in dogs with normal mental status and ability to pause panting.