With a 70 lb dog, I would not pick hardwood. With that said, I would use a matte finish because it shows less scratches. I would also avoid dark colors. They show everything. I have hardwood with a polyurethane finish and two 60 lb dogs. After 3 years, they have look terrible in places thanks to the dogs. I am thinking about having them refinished with Rubio monocoat, so scratches can be more easily covered.

Depends on the light and other design elements. In our dark panelled living room we needed to stay with a natural light oak which also worked in the bright sunroom.We were warned dark stains will show more scratches. Get a good finish to hold up to kid and animal abuse. Sadly that isn't cheap but worth the extra cost. Check the wear rating or warranty.

Hardwood is definitely not a "hard" flooring. It's fragile and will scratch and dent with normal use. If your heart is set on hardwood, choose a style that has hand scraping, and some texture to it. A matte finish is best for not showing scratches as much. See a few below we installed in busy family households. If you choose a floor with hand scraping and a little busier look, scratches and dents will enhance the beauty of the floor.

The type of wood won't help too much with scratching and denting. Jenka scale is a big sales pitch because any of the woods will dent and scratch no matter how "soft". In fact some of the softest woods have so much variation in color it'll hide dents better than the hardest woods available.

Solid 3/4" White Oak in a natural finish or a light stain (mid-tone brown is as dark as you would want to go). A matte finish hides scratches but can show "body oils" from socks, bare feet and paws. A satin or a semi-gloss (semi-gloss is as shiny as I would go) will satisfy the "clean = shiny" person in the home.

The floors will scratch. They will dent (solid Oak would take a bit more effort to dent). They will slowly dull. They will need a "maintenance" coat around year 10-12 (called a buff and coat or screen and coat) and they will require a full sand/refinish around about year 20-25.

This is hardwood. It does scratch and it requires some basic maintenance to avoid a mid-life crisis. Work with flooring that is a close to the natural colour of the wood as possible and you will have the best chance of being happy with your hardwood.

So long as your personality can handle the look of a floor that ages, you should be fine. If you (or someone in your home cannot handle "age") then you might have to look at something else.

There are two factors you need to look at: The wood hardness; and the finish durability. Below is a hardness scale for common wood flooring species. If you look at Brazilian Cherry it rates very high on the hardness chart as does Hickory. White oak rates higher then red oak. A vertical grain white oak will fare even better as less of the softwood is exposed. If you get a factory applied finish that contains aluminum oxide it is one of the hardest finishes out there, but be aware that if it becomes damaged it is very difficult to repair as you will never get the same finish as applied in the factory. The product used in the factory is a sprayed on finish the cures rapidly and cannot be applied in the home. Another very durable floor is bamboo. This would hold up very well to dog traffic and is a sustainable product. VERY hard to refinish if ever needed.

http://www.azwood.com/janka_scale.html