Affective states are central to animal welfare, but practical methods for assessing them with minimal training remain limited. Attention bias describes the differential allocation of attention towards one stimulus compared to others and may indicate affective states because anxiety-like states can bias attention towards threatening cues or alter disengagement from them. We tested whether an Attention Bias Test (ABT) is sensitive to short-term changes in affective states in dogs and whether individual traits modulate these responses. The personality of 16 pet dogs was assessed using the Dog Personality Questionnaire (DPQ) and a behavioural test battery. Dogs then completed the ABT twice in random order: once after a putatively positive 5 min play session with their owner and once after a putatively negative 5 min period of social separation. The ABT involved exposing the dogs to a 14-s playback of a potentially threatening auditory stimulus (lion growl) and we assessed behaviour, the time spent paying attention to the sound and the latency to consume a food treat. We found that dogs paid more attention to the sound after the period of social separation than after play. We did not find clear evidence for a role of personality in attention bias, which is most likely due to the small sample size in this study. These findings suggest the ABT may indicate short-term changes in affective states in dogs, although confirmation in larger samples and across a broader range of contexts is needed.