When female dogs suffer from pseudo-pregnancy or false pregnancy, neutering is recommended to avoid mastitis, tumors and genital infections. The best moment to do it is after having decided the dog will not have any offspring and when the dog is at least 10 months old.
At the moment of the surgery it must neither be in rut, have symptoms of a pseudo-pregnancy (milk in breasts, breasts enlargement, etc.), nor be breastfeeding.
Neutering is recommended when there are unneutered female dogs and you do not wish them to be pregnant, when their behavior turns aggressive because of hormonal changes and also when they suffer from serious prostate and/or perianal glands problems.