The invention relates to a urine collection device for horses. The device comprises a urine collection device which is suitable for mounting on a special harness and a special head part for the same, which is advantageously suited to collecting pregnant mares' urine (PMU) for obtaining natural mixtures of conjugated estrogen (CE). This harness with the inventive urine collection device offers good flexibility and is comfortable to wear for the horse. The freedom of movement of the horse is not significantly reduced by the harness with the urine collection device, so that grazing is possible and it is not necessary to keep the horse tied in a stall. The inventive urine collection device is especially characterised in that the part that catches the urine (9) and the head part (10) are interconnected by a detachable connection (15), e.g., a bayonet joint.