I agree with the prior posts. I have always spayed/neutered any of my furpals and none of them have had a problem during or after. It really is a decision that not only eliminates the accidental pregnancies or isolation for one of them when the female is in heat but it will honestly greatly reduce the chance of some rather serious and life-threatening medical conditions as they get older. Getting rid of the tremendous urges that present themselves if they aren't "fixed" will also ultimately make them much happier dogs as well as make your life with them less complicated.