I am installing a floating laminate wood floor over an existing hardwood floor. My question is do I need to lay down an underlayment and if so which is best for this type of install. Also before anybody comments about doing that, we have already looked into having them refinished but chose this route due to the fact we have 4 dogs who would tear up a new finish faster than they can tear up a laminate floor.

Many laminates have an attached cushion so if you get one of those you shouldn't need any vapor retarder/cushion rolls.
Also you need to protect the floor from underneath moisture as in a damp basement or crawlspace. It may be working great now but if you close it up you could have issues like the hardwood rotting.

We already purchased the laminate and it does not have a cushion attached. There is a crawl space under the house but no basement since we live in Florida....so with that said what is the best underlayment to get as there are so many on the market these days....is the foam underlayment and good? I want to make sure what we get will definitely deflect sound as we do have 4 dogs. Does anyone recommend a certain brand of underlayment?

Any underlayment for laminate flooring that does not have a moisture barrier incorporated into the padding.

Call the laminate manufacturer and ask them what they recommend to protect the warranty. Have them e-mail or fax that to you so you have a paper trail who recommended it.

Geez Perry...where ya been?

Good to see ya

Ken may know better than I about florida but I would assume crawlspaces there are damp seeing how high the water table can be and lots of rain. Better make sure that space is dry. Moisture test the subfloor.

Playing politics