Blot up any fresh urine with paper towels or a clean cloth
Remove all bedding and wash it separately
Mix equal parts white vinegar and water
Lightly spray or dab the stained area with the vinegar solution
Blot again with clean towels
Sprinkle baking soda over the damp area
Let the baking soda sit until completely dry
Vacuum up the baking soda thoroughly
If odor remains, use an enzymatic pet urine cleaner according to the label
Let the mattress air dry completely
Use a fan or open windows to speed drying
Repeat the cleaning process if needed
Use a waterproof mattress protector to prevent future stains