Long-Lasting Chews Elicit Positive Emotional States in Dogs during Short Periods of Social Isolation

SIMPLE SUMMARY: Dogs are a social species and may experience negative emotions when left alone even for short periods of time. This study explored the effectiveness of different food-based enrichments on engaging dogs, and alleviating potential negative emotional states caused by social isolation. The results indicated that dogs spent the most time interacting with a long-lasting chew. They also responded to this enrichment with the most positive and calm emotions when compared to a treat-dispensing toy and a smart treat-dispensing device. Long-lasting chews should be further explored as an enrichment for improving dog emotional wellbeing during periods of separation from their caregivers. ABSTRACT: Dogs may experience negative emotional states when isolated from human caregivers and conspecifics. This study aimed to evaluate how dogs interact with different enrichments during a short period of social isolation, as a first step towards identifying methods for improving their emotional wellbeing. Using a cross-over design, dogs (n = 20) at the Waltham Petcare Science Institute were exposed to four different food-based enrichments while left alone in a familiar room for 20 min: long-lasting chew (Chew), kibble in a treat-dispensing toy (Toy), and kibble dispensed through a smart treat-dispensing device with (Device + Voice) and without (Device) a person talking to the dog. Time spent engaging with each enrichment item and emotional valence and arousal (7-point scale collected every 5-min) were scored from videos. The results of linear mixed models indicated Chew was the most successful enrichment, with dogs having lower arousal scores (p < 0.05 vs. Device and Toy) during the first five minutes of isolation, higher positive valence scores (p < 0.05 vs. all) during the second five minutes of isolation, and spending the most total time engaged (p < 0.01 vs. all). Based on these findings, long-lasting chews should be further explored to assess their impact on dog emotional wellbeing.