Pet urine smell! HELP!!!

[Rob Duhon]

PLEASE HELP!!! I have a beautiful $430K rental home in a great neighborhood. It has tile in EVERY room. My last tenants lived there for 4 years and they didn't take care of the place at all. They had dogs that peed inside.  To try and get the smell out I had a contractor rent a tile steamer, I had an AC guy come clean out all of the vents and I had the entire interior painted... and it still smells AWFUL! Please, does anyone have any recommendations on getting pet urine smells out?