A spokesperson from Kent Fire and Rescue Service said it provided cross border assistance as it responded to the horse which was stuck in a water and mud filled ditch in Rickney Lane, Downash, at 11.58pm.
Dramatic photos, sent to Sussex World by Dan Jessup, show fire and rescue teams using a winch to save a horse named Dixie from the field near Hailsham.
An East Sussex Fire and Rescue Service spokesperson said: “Two appliances were sent. Crews used mud paths, pumping equipment and a hose reel to rescue a horse that had found itself 50 per cent submerged in muddy water. Once rescued, the horse was handed over to the veterinarian. Crews left the scene at 3.07.”