Hungry scent detection dogs more likely to ‘cry wolf’

Dogs trained in scent detection may be better at sniffing out the right smell after breakfast, with new research finding hungry dogs that are working for treats are more likely to falsely identify the wrong scent.

The study, led by researchers from the University of Waikato and Adelaide University, explored how meal timing affected dogs’ accuracy in detecting target scents.

Associate Professor Tim Edwards, from the University of Waikato, said the findings suggest hunger may change how dogs respond to smells when looking for a target.

“What we found is that hunger appears to change the likelihood of a dog saying a target scent is present, rather than simply making them better or worse at smelling,” Associate Professor Edwards said.

“When dogs hadn’t eaten, they were more likely to respond to non-target smells as though they were the target when they were working for treats. After breakfast, they were better at rejecting those non-target smells.”

“The reason for this is probably very similar to the reason that, when you have lost your keys and need them very urgently, every small metallic thing looks like your keys. When we are highly motivated to find something, we are biased toward seeing it or smelling it in the case of our dogs.”

The research, published in the journal Learning and Motivation, involved six dogs trained to identify a target mixture of four odours using an automated scent-detection system.

The dogs completed scent-detection sessions either before or after their morning meal. Researchers found their average rate of correctly identifying the target was around 90% in both conditions.

But when the dogs were hungry, their ability to reject incorrect scents dropped significantly – meaning they produced more false alarms.

Co-author Dr Jade Fountain, who was involved with the study while a PhD candidate at Adelaide University’s School of Animal and Veterinary Sciences, said the finding could have implications for dogs working in environments where accurate scent detection is critical, as well as companion dogs involved in scent work sports.

“For working dogs, a false alarm can matter just as much as a missed target, particularly when they are being used in situations where people rely on them to distinguish one scent from another,” Dr Fountain said.

Dogs are increasingly used for scent detection in fields including conservation, disease detection, explosives and landmine detection.

The researchers say the findings do not mean working dogs should simply be given a large meal immediately before every job. Feeding strategies would need to consider the type and intensity of work, as well as individual dogs and how they are trained and rewarded.

“Our results suggest that feeding strategies could be one factor worth considering when planning scent-detection work, although we need more research to understand how these findings translate to operational settings,” Associate Professor Edwards said.

The researchers suggest hunger may make food a more powerful motivator, potentially causing dogs to respond more broadly to smells that resemble the target rather than being as selective in their responses.

The study also found considerable individual variation between dogs, highlighting the need for further research into how factors such as diet, training, reinforcement and working conditions affect scent-detection performance.

A separate paper published in Behavioural Processes showed that the dogs that had not eaten breakfast were more likely to whine and pay attention to the food dispenser, but they remained engaged with the scent tasks.

Dr Fountain said the results provide an important reminder that even highly trained dogs can be influenced by factors that may seem unrelated to the task at hand.

“Dogs are incredibly capable scent detectors, but their performance is influenced by more than their noses,” she said.

“Understanding how factors such as hunger and motivation affect their decisions could help us get the best possible performance from dogs working in scent-detection roles.”

The research is published in Learning and Motivation and Behavioural Processes.