Chewing the deck...

[Buddy Blaze Lover]

My dog, Blaze, has gotten into a bad habit of chewing up the bottom part of our decks! We put the "cris-cross" wood around the bottom on purpose to keep him out from underneath the deck, but he still chewed through and is digging like crazy under there!! He's not bored--we play fetch with him, walk him and other stuff all the time, plus he likes to romp inside. Any ideas on getting him to stop? He's a border collie by the way...