The name sterilization is actually wrong, in fact it is a ‘castration’, because the ovary + oviduct + the uterus are taken out. But because in popular language they talk about sterilization for the female and castration for the male, I will do the same. I personally don't believe in sterilization for no reason. Sometimes, however, you don't have any other choice, for example if the bitch has a uterus-infection and antibiotics don't help anymore.

Advantage:
*  The bitch doesn't get in heat anymore.
*  The bitch doesn't have false pregnancies anymore.
*  Less chance for developing tumors on the mammary glands.
*  No more uterus-infections.
*  Less chance of developing diabetes.
*  Personality change for better.

 Disadvantage:
*  Sterilization is a big operation and every operation under complete narcosis is risky.
*  Some dogs develop inward scar tissue, which can cause the guts to grow together.
*  Some bitches develop a weak bladder, resulting in constant dripping.
*  The hormone-balance is gone and that can be of influence to the coat (especially the longhairs, these often get a 'fluffy' coat).
*  Because the metabolism changes there is a chance of getting 'fat' (but a good owner must have this under control).
*  Personality change for worse.