I work for a carpet cleaning company and we use a product called FLUOROSIL for pet stains. I don't know if you can order this because we get it wholesale, but you can try: www.interlinksupply.com
If you can't get this product or don't want to wait for it to be shipped try 1 part white vinegar to 4 parts water. I'd probably try this first… might save you some money!
Good luck.