Military working dogs are exposed to high levels of physical load during their work, although this is not always evident from their behaviour. This workload causes various physiological changes, including variation in the temperature of the affected body parts. In this preliminary study, we investigated whether thermal changes following the daily work routine of military dogs are detectable by infrared thermography (IRT). The experiment was carried out on eight male German and Belgian shepherd patrol guard dogs performing two training activities, obedience and defence. The surface temperature (Ts) of 12 selected body parts on both body sides was measured with the IRT camera 5 min before, 5 min after and 30 min after training. As predicted, there was a greater increase in Ts (mean of all measured body parts) after defence than after obedience, 5 min (by 1.24 vs. 0.60 °C, P < 0.001) and 30 min after activity (by 0.90vs. 0.57 °C, P < 0.01) compared to pre-activity levels. These findings indicate that defence is more physically demanding than obedience activity. Considering the activities separately, obedience increased Ts 5 min after the activity only in the trunk (P < 0.001) but not in the limbs, whereas defence increased it in all measured body parts (P < 0.001). Ts 30 min after obedience decreased to the pre-activity level in parts at trunk, while in distal parts of the limbs Ts remained elevated. The prolonged elevation in Ts of the limbs after both activities indicates heat flow from the core to the periphery as a thermoregulatory mechanism. The current study suggests that IRT may be a useful tool for assessing physical workload in different body parts of dogs.
Keywords: Defence; Infrared thermography; Military working dogs; Obedience; Physical activity; Training.
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