Citizen of Zooville
In general, figure that a "spayed" bitch (the usual, but not universal, practice for a spay is removal of ovaries - there went all trace of sex drive - tubes, uterus, cervix, and usually at least part of the vagina, with the remains of the vagina stitched/sealed shut) will almost certainly have little or no interest in sex, and depending on how much of the vagina is taken, it may be physically impossible to insert a penis of any size into her without causing at least pain, if not damage or even fatal injury. Exceptions to this rule are possible, but should be considered EXTREMELY unusual. A wise person will consider a spayed bitch to be sexless.So, on a side note after reading this, call me ignorant if you like but a non-intact female is impossible to have sex with correct? I've been looking it up and trying to find some sort article on intact females vs. spayed. I've become even more confused due to the different types of spaying a female can receive in general and curiosity has gotten the better of me.
A bitch who has had her tubes tied (AKA "Tubal ligation") will be so close to unchanged by the procedure that you might as well consider her untouched, except for the fact that she can be mated by as many fertile male dogs as she cares to stand for, but she won't ever catch pregnant unless the person who performed the operation fucked it up. Purely depending on her own whims, she may or may not be interested in sex with a human, exactly like an untouched bitch, but she will almost certainly accept being mated by a dog when she comes into heat. If she welcomes your sexual advances, you should be able (assuming no size problems get in the way) to mate with her in exactly the same ways you might if she were untouched, because essentially, she IS untouched - it's just that there's "a blockage in the plumbing" that keeps eggs and sperm form getting together.
A bitch who has had a hysterectomy (removal of the uterus and usually, but not always, the cervix and a portion of the vagina, with what remains of the vagina being stitched or otherwise sealed shut) will probably be unenthusiastic about sex, and depending on how much of the vagina was taken, may be physically incapable of accepting a penis without being injured severely, perhaps fatally. This is sometimes called an "ovary sparing spay", because the ovaries are left intact in her body, and will continue to operate as usual. Because she still has her ovaries - the source of the hormones that cause a bitch to have a sex drive at all - she may well come into heat, even though no amount of mating or AI will be able to make her pregnant. If and when she does come into heat, allowing a dog to mate with her is almost certainly a bad idea, since depending on how much of her vagina was taken, he could cause a fatal injury in the process of mating with her. (by tearing open the stub of her vagina as he instinctively drives as deep as he's capable of reaching) Likewise, she may or may not accept sexual advances from a human, the same as an untouched bitch, or one who has had a tubal ligation, but it might not be possible to insert a penis into her depending on how much of her vagina was removed.
A bitch who has had just her ovaries removed will be sterile, of course, and probably won't have any interest in sex, whether offered by a human or a dog, although there's no physical reason (unless it was done so early that her organs never had a chance to develop) she couldn't accept a penis on the off chance that she's interested enough to allow it. Which she probably won't be.