Because of the higher incidence of cancer in sexually intact animals, I recommend spaying and neutering of all pets. This will not change a dog's personality or behavior except in a positive way or cause him/her to gain weight. A neutered male dog is unlikely to lift his leg in the house (a marking behavior common to intact males) or go "crazy" around in-heat females. A spayed female does not produce any discharge which in unspayed females may permanently stain carpets during heat cycles.