Box gardens last best using pressure treated wood that is resistant to rotting. Cedar also works well. Make sure you have good drainage holes or use mesh on the bottom of the box rather than wood. To keep dogs out cover your new garden beds with chicken wire. You can even plant seeds into the spaces in the wire. You can also try a fence around the vegetable garden and some patient training of your pets. Doggoneit. Keep growing, Marianne Binetti