After you have your female dog spayed, will she still bleed at that time of the month?

A spay procedure (ovariohysterectomy) involves removing the ovaries and uterus.  The ovaries are responsible for producing hormones that control the estrus or heat cycle and the bleeding that occurs during heat comes from the uterine lining, since these reproductive organs are removed the animal will no longer have a heat cycle or bleeding occur.  It is ideal to have your pet spayed before the first heat cycle (usually 6-9 months depending on breed/size) to greatly minimize the chance of mammary cancer later in life.