My breeder is registered and has years of experience with chihuahuas. She also suggests that I wait until 8 weeks for their first immunizations. She says that they are too young to be vaccinated at 6 weeks, and if you vaccinate too early they can get very sick and die. I will be keeping the pups inside my house and they won't be around any other dogs or sick people. Am I still putting them at risk by waiting till 8 weeks?