Fraggle Rocker
Staff member
That sounds like an exaggeration. Dogs are not like humans, dolphins and a handful of other mammalian species, in which females are physically capable of performing intercourse virtually anytime, regardless of their estrus cycle. Female dogs and most other species are only capable of it when they are in estrus, or "in heat," i.e. when they're ovulating and their uterus is prepared for gestation. Furthermore, this is the only time that they exude the pheromones that excite the males. A female who is not in heat cannot be penetrated and the males in the pack will not be aroused and therefore cannot attempt it.
Spaying removes both the uterus and the ovaries, the source of the hormones that initiate the estrus. A spayed female cannot copulate and does not produce the pheromones that arouse the males.
Dogs use the posture and motions of mating as a way of establishing and asserting dominance within the pack, but they do not have erections and there is no penetration. In fact males do it to males, females to females, and even females to males. They'll even do it to your leg, either to show you they're in charge, or as a way of asking you to respond more forcefully and show that you accept them as a member of the pack you lead.
Your friend probably observed an instance of this. Neutered dogs do it all the time.
A neutered female cannot copulate and cannot attract the attention of a male intent on breeding.