You need to find a good enzyme cleaner, which have the strength to effectively remove any urine stains. You can use an odour digester, such as the Magic Odour Digester, which removes unwanted odour from soft furnishings and carpets.
Many thanks for your reply. I have recently tried a carpet cleaner product in conjunction with a carpet cleaning machine all that happens, after a number of applications is the smell returns.
I will search for the product that you mentioned.
Many thanks once again.