How to get rid of doggie urine odor from tile floor?

Have you tried vinegar yet?

I use a product called "Odo Ban" from Home Depot or Lowes. It's antibacterial and will remove odors from all kinds of bodily fluids for humans and pets. Great stuff if you have a toddler, too! We had a water heater leak in our basement with accompanying mold and mildew (and nasty odors). This took care of everything. I also had lots of small dogs in the house and this helped, but be sure to really soak the flooring. If this product is unavailable, then while vinegar will neutralize the smell. Urine is alkaline, so you need an acid to counteract.

It is most likely in the grout. Soak it good with straight vinegar and let it dry. Give it a sniff test once you don't smell the vinegar anymore to see if you still have the urine odor. Sometimes it takes more than one try to get rid of it.

Try Nature's Miracle, it's a super product that you can find at your local pet store made specially for this