How well will a laminate floor hold up to occasion dog accidents?

I know what you mean. Laminate flooring comes in different grades and I don't think that one is any better then the other as far as liquid penetration goes. When my cleaner used a mop on mine with too much water I noticed that there was a saturation point and some has lifted.

To answer your question from my own experience regarding moisture getting between the layers, I would say it won't hold up to dog pee.