My 10 year old Child(Dog [THOR]) has the normal callous on the elbow...seems to be bloody...HELP ME!!!!!!!?

Thor's elbows seem to be/have dried blood on them...I know older Dogs have callous' on their elbows...his seem to be weird...it looks like dried blood...I LOVE me boy to death but the vet is cost prohibetive at this point...can ANYONE answer...IS THIS NORMAL/OK???