@GunnyHighway I've seen lots of people put up a puppy pen around the tree so keep the dogs from going under and knocking it down. They make them in wire so you will still be able to see the tree. You could even use a fireplace gate/screen if you have the tree in a corner or up against a wall.
After Gunny had another "episode" with the tree last night so we opted for a late night run to Wally World for a baby gate type of thing. He likes to hide and play under the tree and rip off at least two strands of lights at a time! I will try to get a picture up since our tree looks absolutely ridiculous now! Oh the stuff we do for these awesome bullies.