My vet also said there is a big risk of developing breast cancer when they get older if they are not spayed. He also said this has to be done before the first cycle, to be most effective. So, I had mine done when her second teeth came in so they could pull the baby teeth at the same time. Hope I did the right thing! I have also had a dog I didn't spay, and it was a big pain everytime they came in heat.
Pat |