The problem with hard wood is that it most likely will get damage if your dogs todo their business on it. May I suggest a faux-wood look porcelain tile. They are low maintenance, low cost, and durable. These will surely last and will be great. The only downside is, if you live in a cold climate at winter, the floors will be freezing. But in the summer time, if you want something cooling to the feet, use this tile. But if you always live in warmth, this is a good option.

Just an example (respond if you want to see more option):

http://t.homedepot.com/p/MARAZZI-Montagna-White-Wash-6-in-x-24-in-Glazed-Porcelain-Floor-and-Wall-Tile-14-53-sq-ft-case-ULG2/203600149/

Our dogs are great in the house. We both work out of the house and the dogs do not make messes. My concern is mostly with their nails, which I do keep trimmed. The tile is not appealing... Too cold in Connecticut!

Maybe using a laminate flooring would better suit you guys, as it is durable.