Pet Odors

Dear Jen,

I foster animals (mostly dogs) for a no kill shelter and unfortunately get quite a few urine accidents in my carpet. Is there any effective treatment to get rid of this odor. I usually treat the accidents shortly after they have occurred, but cannot seem to get rid of the odor even after drying. Have tried just about everything on the market and even a vinegar, lavender and peppermint mix but does not seem to eliminate the odor. I have a portable carpet shampoer that I can possibly put some essential oils in so wondering if that might be a possible help. Thanks for you help. Selina.