Generally speaking—certainly in the forestry sector—shipping and moving wood with the bark on is regulated. If you've crossed a provincial boundary in western Canada, I'm sure you've seen the signs that say not to bring firewood back into Alberta, or into B.C. There certainly are restrictions there, but obviously there's not a lot of enforcement for some of those particular things.
For imported goods, I'm not a hundred percent clear on exactly what is done to treat the wood that is coming in from, say, the United States. Obviously there do need to be guidelines in place for ensuring the wood is either heat-treated, or debarked or both.