I started doing a regular routine of enzyme treatments every few months I use either Ridex or the enzyme sticks by Green Gobbler down each sink and shower every month or so and no problems since. 

To clean it, you would need an enzyme cleaner and it must be liquid, to pass into the concrete itself. 

Oh ya, pet stores sell pet urine liquid enzyme eliminator but it's pretty pricey

I also use "Nature's Miracle" or another enzyme formula.I no longer allow pets, other than in a house with ceramic flooring.

I put all new flooring in the upper level of their unit, its a bi-level duplex, and the bedrooms are in the basement, which has carpeting, as did my side, but I tore my carpet out due to years of dog urine never cleaned out of it, which soaked into the cement and even after enzyme cleaning and layers of scent sealing paint and then vinyl plank flooring, I can still smell it in the damp weather.

Had to tear everything out, several coats of commercial enzyme cleaner and several coats of kilz restoration primer. 

These cleaners contain special enzymes that convert organic waste materials such as urine and feces to carbon dioxide and water.

-Enzyme solutions are available at pet stores and do a great job of eliminating odors because it's basically good bacteria eating bad bacteria.  

The bathroom floor and part of the subfloor in the hall and kitchen would have to come-up; the wall between the bathroom and hallway and across the end of the hall would be going back to the studs; the common wall between this apartment and the adjacent unit would need to be brought up to current {fire} code; the ductwork for the HRV needed to be replaced; and three of the existing windows had broken thermo panes.We also planned to improve the energy efficiency of much of the envelope during this renovation - the amount would depend upon what we found behind the drywall.What we found:The damage to the subfloor on both levels was more extensive than forecasted and I wasted two weeks, and a few hundred dollars in materials, over the holidays in December trying to remove the smell of pet urine (ozone, enzymes, sealant, etc).  

The enzyme odor remover combined with the use of an ozone generator seems to be working.