What is the best way to remove pet stains from light colored carpeting

Test a spot in the corner of room. Try using OXY Powder with water . Hope that works for you.

I used Clorox Cleanup. My carpet is almost white, the stain was gone and the cleaner did not leave a stain. Try it on a hidden place first

I use a commercial product from the pet stores for blood, urine, and food stains even wine on Wool Persian carpets even....test spot.

Try Odoban from Home Depot. 9.99 per gallon makes 32 gallons but for old stains I would use it full strength with a scrub brush and a bucket of water to rinse the brush. Kills 99.9 % of bacteria and comes in citrus, lavender and my favorite eucalyptus. Been using it for odor and stains plus to mop my floors. Even in the laundry!

Did you have someone steam clean the carpet?

Purchase Nature's Miracle from Amazon.com. It is guaranteed to remove the stain and any odor. It works!