Effects of feeding on dogs' frustration-related behaviours during a laboratory-based scent detection task

Dogs often use their keen olfactory abilities in laboratory settings to support scent detection research. In cognitively demanding tasks, pre-feeding appears to influence engagement and performance, but the effects of hunger state on dogs' frustration-related behaviour during scent-detection work has not previously been examined. We analysed overall behaviour patterns observed during a laboratory-based scent detection task and evaluated whether dogs exhibited frustration-related behaviour changes as a function of having had breakfast before the task. We expected to see an increase in frustration-related behaviours when dogs were working prior to eating breakfast. Behavioural observations were extracted from video recordings of six dogs participating in the scent-detection task. During the sessions, dogs spent the greatest proportion of time with the tail held low (85%) and still (73%). Whining and engagement with the feeder and scent detection apparatus was higher when dogs had not eaten before the task, consistent with mild frustration, although behaviours varied between dogs and these differences were primarily driven by one or two dogs. Regardless of condition, lip licking and ground sniffing occurred more frequently earlier in the day, with lip licking also increasing over the course of the study. These findings suggest that working prior to a meal may have a mild effect, increasing frustration-related behaviours in some dogs, but additional research is required to clarify potential mechanisms underlying this effect. The low levels of frustration-related behaviours more generally suggest that laboratory scent-detection tasks, similar to the present task, do not reliably evoke such behaviours.