True! You leave yourself open to bone and joint problems when you spay early. It takes commitment to your dog's health to wait, AND, you'll take lots of flak from your vet because most of them want to get you in and get it done right away. They'll try to scare you about possible cancers that your dog could get, but several studies show the opposite is true. Most people here have waited. Heats aren't easy, clean up, etc., but balance it against your dog suffering and you paying for expensive surgeries and the math is clear.