When it was time to replace my floor we looked at wood, tile, or carpet. We eventually chose Pergo and have never regretted our decision.
I was concerned about wood because we, too, have a dog. Her nails have never been a problem with the floor and even after a year we have yet to see a scratch. To test the floor I took a sample home from the store and subjected it to a lot of torture: scratching, hitting with a hammer, etc. I have yet to find a way to hurt the floor.
Also, if you ever do scratch the floor, Pergo makes a product (like an epoxy or caulk) to fill in any voids with a matching color.
The best part... everyone who has seen the floor can't believe it's not wood.