I recently talked to a guy at a pet store who sells the hormone injections for dogs to prevent puppies and he told me that if I give one 1 ml shot three months in a row my dog should become infertile and I will never have problems with puppies again. Last month, I gave one shot and I plan to do it again this month and next. Usually an injection lasts for 4-6 months from what I heard. I'm guessing the excessive amount of hormones destroyes the eggs or something. Will this work or is the guy pulling my leg? Does anyone have experience with this way of 'fixing' a dog?