A recent study described an inactive state in domestic horses, termed withdrawn hereafter and characterised by an atypical posture and low responsiveness to tactile and environmental stimuli. Aiming at determining the potential role of underlying depression in this state, we investigated whether the attentional state, frequently impaired in depressed patients, differ between withdrawn horses (n = 12) and control non-withdrawn animals from the same stable (n = 15). These 27 horses (5 mares, 22 geldings, French Saddlebred, 4-20 years old) were exposed once a day for 5 consecutive days to a novel auditory stimulus, broadcasted for 3 seconds in horses’ home environment. We recorded standard measures of attentional state (e.g. time spent with ears, head and/or neck orientated towards the loudspeaker). Different temporal patterns of attentional responses appeared: withdrawn horses paid less attention to stimuli on the first day (Wilcoxon, p<0.05), while control horses similarly paid attention to stimuli over the 5 days period (Friedman p>0.05). Moreover, time focused on the loudspeaker was lower in withdrawn than in control horses on this first day (Mann-Whitney, p<0.05). Withdrawn horses therefore seem to “switch off” from environmental stimuli compared to control horses, which might reflect lack of attention.