Stress and behavior assessment in police dogs due to challenging situations: Differences due to training objectives.

Abstract

Police dogs have been trained to maximize their search capabilities and are required to maintain levels of intense concentration during their working time. The main aim of this study was to evaluate stress and behavior differences in police dogs due to different scenarios and distractors according to type of training: detecting narcotics or explosives. A total of 18 dogs (14 males and 4 females) were measured. 8 were trained for narcotics detection and 10 for explosives detection. In order to test the stress reaction of dogs, 3 scenarios were developed for each type of training, being differentiated by the difficulty, Scenario 1 the easiest one, Scenario 2 an intermediate-difficulty test and Scenario 3 the most challenging one. Then, these scenarios were performed a second time, including an environmental distractor: an olfactory distractor for S1 (S1D1), an auditory distractor for S2  and a visual distractor for scenario 3. The animals’ stress levels were measured with eye temperature (ET), assessed with infrared thermography, and heart rate (HR). Behavior was recorded for each animal on each scenario. These parameters were then grouped in 3 behavior aggrupation’s counted in 4 scores each: Attention, Effectiveness and Fear. A descriptive analysis showed higher ET means in dogs trained for explosives’ detection for most of the scenarios. A General Linear Model and Tuckey post-hoc analysis for different environmental and behavioral effects, found that ET showed statistically significant differences for scenario effect with both narcotics’ and explosives’ trained dogs, with S2 showing the highest ET values and S1D1 the lowest, whereas, according to behavioral effects, statistically significant differences were found for attention in narcotics’ trained dogs and for effectiveness in explosives’ trained dogs, with score 4 showing the highest ET means for both behavioral aggrupation’s. On the other hand, Mann-Whitney U Test between behavioral means, showed that, explosives’ trained dogs showed higher Attention scores but lower Effectiveness scores than Narcotics’ trained dogs. Finally, ET showed medium and positive statistically significant correlations with Attention in narcotics’ trained dogs (0.34) and with Fear in explosives’ trained dogs (0.26), HR parameter showed a medium and negative statistically significant correlation with Attention in narcotics’ trained dogs (-0.31). Our results indicated that explosives’ detection dogs showed more excitability, and less effectiveness behavioral signs than narcotics’ detection dogs, with no differences found related to fear signs.