Blot up as much urine as possible with clean towels or paper towels
Remove bedding and wash it separately
Mix equal parts white vinegar and water in a spray bottle
Lightly spray the stained area without soaking the mattress
Blot again with clean towels
Sprinkle baking soda generously over the damp area
Let it sit for several hours or overnight
Vacuum up the baking soda thoroughly
If needed, repeat the vinegar and baking soda process
Use an enzyme cleaner made for pet or urine stains on stubborn odors
Let the mattress dry completely in a well-ventilated area
Use a fan or open windows to speed up drying
Place a mattress protector on the bed after cleaning