To remove a blood stain, clean the area with dish detergent and water or rubbing alcohol, rinse the carpet with a small amount of cool water and remove excess moisture with paper towels. Use ammonia or hydrogen peroxide to remove stubborn blood stains.
To remove a fresh blood stain, mix 2 cups of cold water and 1 tablespoon of liquid dish detergent, blotting the mixture over the stained area with a paper towel. Continue blotting until the stain is lifted, replacing the paper towel as needed during the cleaning process. If the stain persists, combine 1 tablespoon of ammonia and 1/2 cup of warm water and apply the mixture sparingly. Rinse the carpet with a small amount of water and dry the carpet.
Rubbing alcohol also removes blood stains. Pour a small amount the alcohol on the stain, blot with paper towels and rinse with cool water. If the stain persists, clean the area with a mixture of 1/4 teaspoon liquid dish detergent and 1 quart of water, and rinse with a small amount of water. To remove dried or difficult stains, spray hydrogen peroxide on the stain. Allow the peroxide to remain for one hour, blot dry and reapply as needed.