The extra testosterone in their system makes cancer more likely. That is true of humans as well, in certain cancers. And yes, I know of human females who have had mastectomy before breast cancer showed up because of a high incidence of breast cancer in her family. And I get a mammogram every year - but I know why I am putting myself through that discomfort. Once cancer starts in a particular organ it can spread, and there is big danger in it going metastatic before you notice symptoms of the initial cancer.

The extra testosterone will effect personality - as it does in humans too, it can cause increased aggression in dogs or people. Once those pathways are built in the brain, it is much harder to train the behavior away. Brains are not computers, they do not have an "undo" button. Think of it like writing a word on a piece of paper - you can erase it, but then the eraser marks will still be there, the paper is changed forever.

None of us have an financial stake in whether or not you have your dogs neutered. But many people here have more life experience and have worked with dogs longer than you've been alive.

We don't know you, we just want what is best for your dogs. You asked for advice, we are sharing it with you.