How do you get the smell of dog urine out of particle board floors?

Nothing that I can think of. The particle board is porus and has absorbed the urine. Your best bet is to replace it. Particle board is super cheap.

Replace the flooring, sorry no other way.

I would use 5/8 inch plywood.

Odetta, , I have no experience with particle board floors but every time my dog has an accident in the garage, right away I spray the spot with Water/vinegar/tree tea oil/dawn, mixed in a bottle...then I hose the floor or mop off...no smell there!!

thanks everyone it is a house I was going to buy ,that is what i thought would have to be done ,guess I'll pass on the house

Hi Odetta, so sorry to hear that. It's a common problem. Mix ¼ cup of baking soda with 1 cup water, 1/3 cup distilled white vinegar, and about 1/4 cup of mild dish soap. Put the solution in a spray bottle a mix thoroughly before spraying it on the stain. Rub it in lightly with a clean cloth and let it stand for about 20 minutes. Rinse the solution away with a damp cloth and let it dry thoroughly. Be sure to test the mixture first on a spot to make sure it won’t discolor or damage your floors.