Cyst, Liquid, or Muscle on a Colt?

My colt is one year old and he laid down (by himself. No one was around at the time) in a calf chute. Judge is too big to be in a calf chute and when he got up there was a huge swelling on his neck. Like its the size of a foot ball and is warm to the touch. Some people are telling me it is just his muscle swelling and will go down while others are telling me it is liquid that needs to be drained. Can any tell me what it may be?