If you decide to delay spaying or neutering your dog, for whatever length of time or whatever reason, here is something else to consider- Some people just may not be cut out to deal with an intact male or female dog in their household. Here are some caveats and considerations:
1. Female dogs do not get menstrual periods like humans, as some people mistakenly believe; they come into “heat,” or “season,” once or twice a year – the three to four days in their cycle when their unfertilized eggs ripen. (Though both biological processes involve bleeding, it’s inaccurate to compare a woman’s monthly cycle, which is an infertile time, to the heat in the female dog, which is quite the opposite. Dogs get pregnant while bleeding.) Some dogs cycle every six months; more primitive breeds, such as Basenjis or Tibetan Mastiffs, come into heat only once a year.
2. Female dogs can only get pregnant when they’re in heat, after about 6 months of age. Some females will show physical signs of readiness – their discharge will lighten in color, and they will “flag,” or lift their tail up and to the side. Others will show no behavioral changes; still others will “stand” and accept a suitor at any time in their cycle, even days before or after they are fertile. If you cannot be absolutely certain of identifying the signs of heat in your female, and securing her during this time, spay her. Intact males are frighteningly persistent in reaching the object of their desires; they will hurl themselves through glass windows, and might even attempt (and succeed) at breeding a female through the wires of a crate.