It is generally not advised that anything be used to 'seal' bark wounds to trees. Even up any peeled away places with a sharp knife so that it cannot be ripped further. The tree's phloem is located in that stripped off bark, so it can't do without huge amounts of it.

I have no idea what might be doing the damage, other than those aimals you suggested. Rodents will strip bark for moisture, food, and to make nests.

Not knowing where in Arizona you are located, there are a few things that come to mind. This does not sound like the normal little critter munching on bark and/or fruit. This sounds more like one of Arizona's larger wildlife is visiting the tree. This could be anything from a bear to and antelope, deer, or elk. Many of these animals can easily reach the 5 or 6 foot height you describe. Look at the area carefully and see if it looks scraped, rather than chewed. Many animals will use this method to mark their territory. You can also take a picture of it and take it or email it to your local wildlife center.

When I lived in Florida, I had a bear that was marking several trees on my property. We did not find tracks until after it rained and the ground held the shape of the foot prints. Look very carefully around the tree and its surrounding area for any thacks or droppings. Many times this will give you a good clue as to what might be visiting.

If I am way off base, please post a picture so we can investigate this further. If you can't post a pic you can email it to me and I will post it for you.
Andi