This info is from one of the staff members at a very well-known Veterinary College:
Dr. Ham explains, "Spaying a dog before the first heat can greatly reduce the incidence of mammary cancer in dogs. By removing the ovaries and uterus (known as an ovariohysterectomy or spay) before the first heat, we prevent the first flux of hormones."
Studies in dogs have shown that the risk of developing mammary cancer is 0.05 percent if the dog is spayed before the first heat, 8 percent if spayed after the first and before the second heat, and 26 percent after the second heat...
Letting her have her first heat, IMO, does put her at a significantly higher risk for cancer, which, as we all know, is probably the leading cause of death in Goldens anyway. Why stack the deck against her even more when the type of cancer associated with spaying later is so easily preventable?
Karen, Chance and Savanah *RB*