Removing Dog Urine from Cement

I've always used bleach and a PineSol type cleaner w/ a good jet spray on the hose, and a broom. Put down the bleach and PineSol. Let sit at least 10 min, get the rough broom and scrub. Then go back and hose off w/ power spray. If the sun hits that area, all the better.

I think if you rent (or borrow) a pressure washer, you should have good luck cleaning it. I would ask at one of the home construction types of stores what a good cleaner for concrete would be and use that. I would use that cleaner, rinse well, and if it still looked bad, mix a solution of bleach, detergent, and water, and scrub it with a long handled brush, then rinse and power-rinse.

I suspect any odors would be gone; but if some staining remains, you could stain the concrete with a product from the same store. Or, if you feel creative, stencil some leaves, or flowers, or the like randomly over the patio. I have even seen people paint faux bricks on patios with enviable results!

Good luck with the new neighbors!