When I was little my beagle, Daisy, was spayed when she was almost 8 years old (well, it was the 70s...) and it turned out just fine. We had Kobie spayed at 6 months old, and believe me the worst "effects" of the operation were on us humans! I was a basket-case before the surgery, paced constantly and couldn't eat the morning of the surgery, and doted on her for days after the operation; my DH laid on the floor with her while she wore her "lampshade" and hand-fed her. Kobie probably wondered what the heck all the fuss was about, and in about a day and a half she was back to being her usual self! Don't worry, it's no big deal. And it's much healthier than not spaying at all.