Sorry the honest answer is stop your dog peeing on your patio. Create an area of the garden where he can pee or walk him so regularly he does not need to pee in the garden. Urine on paving slabs, especially if they are the ones made on concrete is going to stink no mattrwhat you do.

All I can think of is Jeyes fluid, which smells just as bad.

Not any more it doesn't - the old version did, but the EU has decreed that the 'smelly' ingredient is a banned chemical, so good old Jeyes smells entirely different. :-(

Cookygirl, there's an animal repellent spray that you can get at B&Q - try spraying that on the patio to heep him off there. My Lab. hates it!

Try biological washing powder. It should do the trick. It may also discourage him from using the patio in the future.

But don't let the water get near your plants.

thanks everyone