Like Renee said, you own the house, so you can put whatever kind of restriction you want on it.
Saying no intact female dogs, totally logical. They have a messy heat and *if* god forbid the dog got preggers, your house would be a kennel. Nope, that's a no go. That's two problems that the other two categories (intact males & altered animals) don't have.
Restricting intact male dogs isn't "fair" or logical, to me. Housetrained is housetrained, whether intact male or altered, and they have equally non-existent chances of having a litter in your house. But that's JMO, it's your house, you pay the taxes, if I, or this house-seeker don't like it, we have to go somewhere else, that's life when you have animals and rent.