For the carpet you will have to remove the carpet, padding and tack strips. Then inspect the subflooring. If the urine has soaked through to the subflooring, it may have rotted and need replacement. Even if not rotted, if saturated with urine it might need replacement. I don't know for sure if sealing the wood would totally eliminate the odor. A simple washing of all walls, ceilings and moldings with a cleaner may get rid of much of the smoke smell, but if not you may have to paint with KILZ.

I had a house and had the ply underfloor sealed with a thick compound that a professional applied and it worked great. Couldn't smell anything and my cat didn't seem to smell it either. They rolled it on; I am sure any floor professional/contractor/or company that specializes in damage from water etc can help.

remove all carpet and pads.

place a dish of vinegar inside each room with windows and doors closed for 24 hours. That should take care of all odors.

while floors are bare, check for rot.

place 4 mil plastic drop cloth on floors to be carpeted to protect from your dogs having accidents and soaking into the floors. Pad and carpet normally on top of plastic.

Walls with smoke odor: First wash walls, cabinets and ceiling with TSP real tri-sodium phosphate. TSP is very harsh so you will need to refinish kitchen cabinets but it will get odor and grease and smoke residue off. Rinse very well. If you want to be really through paint walls with Z-lac a stain and odor blocking sealer. Zinser and Kilz also make products. Read their descriptions online.

Floors: remove carpet, pad and tack strips. If concrete seal with a masonry sealer. If wood or OSB seal it with one of the above products. Can apply with a roller attached to a handle, no need to do it on hands and knees.

As a worst case you may have to seal the underfloor if the urine has penetrated that far.

There is a foreclosure home that I am interested in but the carpet is completely damaged and is drenched in pet urine as if animals had been left in for weeks. I do not know whether it is a dog smell, cat or both. The house is also full of a strong smoke stench. I am interested in the home. I would have to rip out the carpet and install new carpet or other flooring. I dont know what all that entails in order to make sure the smell is completely gone. I am worried my two little dogs will go crazy in there. I don't know if i should take on this project. I would be asking for a cheaper price on the home of course, but I want to aquire some knowledge on the topic before making any decisions.

Thank you!