The surgeon makes a small incision on her abdomen (belly area) and removes the two ovaries and uterus, usually just above the cervix. All vessels and tissues are ligated (tied off) to prevent bleeding and lessen chances of post-operative bleeding or infection. Once the ovaries and uterus are removed, the surgeon begins the closure of the body wall and skin -- muscle, subcutaneous, and skin are sutured (stitched) back together
I got this from this site:
http://vetmedicine.about.com/library.../aa100500a.htm