Investigating Cognitive and Motor Bias in Dogs: Test Outcomes are Affected by Method and Breed

Cognitive bias and lateralization/motor bias tests have been used to indicate animal affective state and welfare, particularly in dogs. This study examined the relationship between cognitive and motor bias in dogs tested in their homes, where any negative impacts of testing stress might be minimized. Motor bias was tested using the typical Kong Classic™ toy, as well as a novel toy for which paw touches generated movement- the Kong Wobbler™. Beagles and huskies were trained to associate two bowl positions with reward or no reward. Cognitive bias was assessed by relative latency to approach a third bowl (ambiguous) position. Beagles had a significantly higher positive expectancy score (PES) than huskies, indicating they treated the ambiguous position similar to the rewarded position (i.e., positive affect). However, the latency of the huskies, but not the beagles, to the ambiguous bowl position increased over test trials, possibly indicating that the breeds treated the non-rewarded test trials differently. In the motor bias test, the Kong Wobbler™ generated a higher rate of paw touches, with no significant differences in the direction or strength of motor bias compared to the KONG Classic™. However, our timed approach to the paw touch tests (vs. a required number of paw touches) did not reveal statistically significant lateralization in the dogs. Despite this, there was a significant correlation between affect and direction of lateralization; dogs who preferentially used their left paw during the Kong Wobbler™ test had lower PES. These results suggest that small methodological changes (home testing, Kong Wobbler™) hold promise for future research and that more consideration of breed effects in the interpretation of cognitive bias test results are warranted.