In the event of an escaped horse

If the horse is not to be found phone vet (Archway vet 015395 32669)
Use social media to put out a call
If it is around the yard make sure all gates are closed
Search all the fields and surrounding ditches. If a horse is in a ditch, approach it slowly and quietly, attatch a rope around its belly with the loose ends coming out between the front legs. If you have no help call the fire brigade