After managing a laundromat wash dry fold business for over 15 years, I have learned a trick or two along the way. I deal with dry blood stains often, especially on sheets and they can most definitely be a chore to remove but it isn't impossible. Ptosis was correct in using peroxide, but I do not agree that it has to be a fresh stain. Of course the sooner you start removing the stain the easier it will be to get out but It doesn't mean that it can't be removed once dried.
Using cool water wet garment and try to loosen up any blood that you can. You have to test the material in question for color fastness first, once you know the color is safe you can cover the stain in peroxide and let sit for 10 minutes. Rinse, and repeat until stain is gone. If the stain is stubborn, make up a quart of cold water and add about 3 tablespoons dawn dish liquid and 1/4 of ammonia and soak over night. Wash as recommended.
If neither of these work for you, go out and get a bottle of resolve carpet cleaner. Spray on stain let soak for 30 minutes or longer, respray and wash as usual.