Mad Cow

I dreampt I was attacked by at cow.  I was walking on a trail in a grassy field.  There were a lot of rolling hills so the view was obscured in places.  As I came around a curve I saw a calf in the road that maybe had been hit by a car.  I approached the calf when I heard another cow, I assume it was the mother.  She charged me, knocked me to the ground and began to trample me.  I felt I could not get up , if I tried the cow would just keep pummeling me.  I heard someone yell and try to stop the cow.  What I remember next is seeing a young man on a stretcher because an ambulance had arrived.  I heard someone talking about "going into shock."  I could feel my body shaking with fear and pain.