A five-year-old boy was airlifted to hospital after being knocked over by a horse.
The incident took place near Deer Park, Henfield, at around noon on Sunday.
Sussex Police said the incident was not suspicious.
A South East Coast Ambulance spokesman said: “Two ambulance cars and two ambulances attended the scene and again we assigned the air ambulance to attend.
“A five-year-old boy had reportedly be knocked over by a horse. He was airlifted to Southampton General Hospital with injuries which included an injury to his head.”