Dogs trained to detect odors can be less selective in identifying a target odor when they are hungry, increasing the likelihood of signaling the presence of that odor. The conclusion stems from a study by the University of Waikato and the University of Adelaide, published in the journal Learning and Motivation.
The investigation involved six dogs trained to identify a specific mixture of four odors using an automated detection system. The animals performed detection sessions before or after their morning meal.
The average rate of correct identification of the target odor was about 90% in both conditions. However, when hungry, the dogs showed a significant decrease in their ability to reject odors that did not match the target, thereby producing more false alarms.
According to the researchers, hunger does not necessarily alter the ability to detect odors, but it may influence the animal’s decision about whether a given smell matches the target they are seeking. The greater motivation to obtain a food reward could also lead the dogs to respond to odors that are similar, yet incorrect.
The importance of false alarms
The results may be relevant for dogs employed in activities where rigorous odor detection is essential, including wildlife conservation, disease detection, and locating explosives and landmines. A false alarm can be as important as failing to detect a target, especially when decisions depend on the animal’s ability to distinguish between different odors.
However, the researchers warn that the results do not mean that working dogs should simply receive a large meal before every task. Feeding strategies will have to consider the type and intensity of the work, the individual characteristics of the animals, and how they are trained and rewarded.
The study also identified considerable differences among the dogs, reinforcing the need to investigate how factors such as feeding, training, reinforcement, and working conditions influence odor-detection performance.
A second study, published in the journal Behavioural Processes, showed that dogs who had not taken breakfast exhibited a greater tendency to whine and to pay attention to the food dispenser, although they remained engaged in odor-detection tasks.
The researchers consider that the results show that, even in highly trained dogs, factors seemingly unrelated to the task can influence behavior and decisions during odor detection.
