Problem
Pet food stains on carpet.

How to solve
Improper cleaning can permanently set food dyes often used in pet food (think of using vinegar to dye Easter eggs). A pet stain should never be rubbed because this can deform the fibers and drive the stain deeper into the carpet and padding.
Rather, blot the stain and call a professional carpet cleaner trained to use specific products and techniques and solutions to remove the dye.
-- Tips courtesy of HomeAdvisor.com