| My first male acted like an intact male, no thyroid issues, had LOADS of energy. He was neutered at 4yo. Current boy neutered at 2yo and has low thyroid, he is more easy going but that's probably because he's being treated for a serious disease at the moment. Thyroid could be associated with his genetics since he is blue; I've noticed dilutes have more thyroid issues. But really, there are more "side effects" leaving a dog intact |