Limb use, an indicator of hemispheric functioning, may be a useful predictor of cognitive bias and hence vulnerability to welfare risk. The relationship between cognitive bias and motor asymmetry, however, has been subject to little investigation. This study explored the association between motor asymmetry and cognitive bias in the domestic dog, a species that displays lateral bias in the form of paw preferences and exhibits positive and negative affective states. Thirty pet dogs had their paw preferences assessed using the KongTM ball test. The subjects’ affective state was assessed using a cognitive bias test in which the animals’ latency to approach a bowl placed in one of three ambiguous positions was recorded. Animals veering more towards a left-paw preference were found to be significantly slower to approach the bowl placed in one of the ambiguous positions than ambilateral or right-pawed dogs. Left-pawed subjects approached the bowl located at the 3 ambiguous positions at roughly the same speed, while ambilateral and right-pawed animals became increasingly slower to approach the bowl the further it was located from the baited food bowl. The study points to a possible relationship between cognitive bias and paw preference in the dog, with left-pawed animals being more negative or “pessimistic” in their cognitive outlook than right-pawed or ambilateral individuals. It is proposed that limb preference testing might offer a more practical and straightforward way of identifying individuals at risk from poor welfare by virtue of how they perceive the world than more time-consuming cognitive bias tests.