Works on old stains

I didn't know this product would work so well I would want to write a review singing it's praises. Since I didn't have a before and after photo of old pee stains on my white carpet. I elected to submit a photo of Lulu who produced those stains. Lulu passed from renal failure. At the end she would pee occasionally in the house. Those deep yellow stains were impossible to remove completely. I cleaned spots using different products but the discoloration remained on the white carpet. UNTIL I used My Pet Peed. I had to apply several times as directed but these were old stains from a dog in renal failure. I am so happy with this product. I now have a puppy and she is not yet potty trained, I know I will be buying more because it works beautifully.