Goat Attack

Around 4:30 a.m., I hear one of my goats scream.  It is dark, my dog ran out before me, I get to the goat pen and there is dust flying.  I check on the goats, something was in there but it licked them or drooled all over them.  They were scared to death.  A dog getting into their yard have to really work to get into their yard. Yes, we live in a residential area out of town but, my goats are in their own fence inside a fence.  Their back fence is 6' tall and is covered with bushes so the dog either went over my neighbors fence and then my fence to get in their pen from the back, or it came over my front fence and then went over their fence.  All fences except the back one are only 4' tall.  I sat out there in the dark with them until it got light.  Every time I got out of their sight they would yell, most of the morning.  We researched electrical fencing and spent the after noon putting electric fence around their pen.
But, they have been yelling since it got dark and finally got quiet.  I think they are afraid something will come in again, but we fixed the problem.