Man seriously injured after being thrown off horse near Hailsham
Emergency services including an air ambulance were called to the scene on the A271 by the Boship roundabout in Lower Horsebridge at 5.50pm.
The rider, a man in his 60s, was air lifted to Royal Sussex County Hospital in Brighton with potentially serious injuries, said SECAmb.
The incident happened after the black horse was reportedly spooked by something.
There was significant delays on the road as the animal ran through the area, drawing a cart.
Police received a number of calls from people seeing a horse-drawn cart with only a dog on board.
The horse eventually collapsed in London Road, Hailsham, said police.
But officers who attended the scene said the horse was back on its feet and would be seen by a vet.