Care given to animals, such as grooming for horses, can be a source of well-being when carried out correctly. However, it can cause discomfort when badly perceived and lead to potentially dangerous reactions. This study aimed to describe how grooming is conducted in the field, in terms of the horse's emotional state and also rider safety. Our observations carried out on 69 horses in riding centres and sports stables show that grooming produces more negative than positive emotions. Indeed, only 5% of horses showed mutual grooming, approach or relaxed behaviour, whereas four times more horses expressed avoidance and threatening behaviours. These results have consequences for handler safety. Regarding threatening behaviours, nine incidents (a hoof or teeth passing within 10 cm of the rider's body or head) were recorded. Concerning riders, 100% behaved in a risky way at least once: passing behind or under the head of the horse without keeping it in the field of view (97%) or squatting by its feet (42%). On average, riders carried out 6.7 + 0.49 dangerous behaviours per session, and sometimes up to 19. Moreover, only 7% of them wore a hard hat when preparing their horse, while the risk of concussion is just as high on foot as in the saddle. Finally, 88% of them showed posture which was risky for their backs when picking out hooves. Surprisingly, riders' experience had no effect on the parameters recorded. In particular, horse professionals were just as exposed to risky situations, did not protect their backs, and their horses showed similar levels of defensive behaviours or signs of discomfort as the less experienced riders (P > 0.05). This result is undoubtedly linked to the lack of importance granted to this practice and little teaching about reading horse signals indicating comfort and discomfort. We hope that our results will make riders aware of how important grooming is for the horse's welfare as much as for their own health and safety.