I have seen refinished hardwood that still had a faint odor, so it can be a challenge..
What kind of pet? Cats are the toughest, but repeated urinating in the same place by any animal is going to be hard to remedy unless you can permanently seal the floor and surrounding surfaces.
First, use a commercial grade of enzyme to neutralize the urine.
In corners and along the wall, be sure to get behind and under the baseboard, and you may have to seal, prime and paint the walls as well.
All soft, absorbent surfaces in the area need to go. Grout needs to be removed and replaced on tile floors.