The bark on my small redwood tree was torn off completely by a new dog, "ringing" it. What can I do?
Heal a Ringed Tree
Certified GKH Gardening Expert
That is terrible. Unfortunately, this usually means death for a tree. You might try grafting tape, but if it is ringed all the way around, then it is destroyed. That small layer beneath the bark is where the nutrients are transported, so if that is disrupted, then the tree will more than likely die.
Here is an article for more information:https://www.gardeningknowhow.com/ornamental/trees/tgen/how-to-fix-girdled-trees.htm