My son is hanging out at Lake Mead (near Hoover Dam) today. He had his boat beached along the shore line and was letting his dog take a run.
He looked up, saw an eagle circling, grabbed his cell phone and started taking a video. Suddenly he saw the eagle start to dive. He sent me this very, very short (2 seconds) video which shows the eagle starting to swoop.
Now zoom in on this image. The brown spot on the ground just to the left of the dark grey area is his dog. The eagle was heading directly towards the dog.
My son started yelling, jumped out of the boat, running and waving his arms. The eagle pulled up and flew towards the mountains in the background. Later on my son grabbed his binoculars and spied a nest of 3 eagles.
This is the one he was dealing with.
I can't really say who would have won this fight, but my son's dog is pushing 10 years old and weighs about 15 lbs. I'll bet he would have been seriously hurt if contact had been made. He was just lying in the sun when the eagle started to swoop.