It's extremely rare for us too, yes.
E.G. has never had a pet. Everytime he's gotten too close to a cat, he has a life-threatening asthma attack. He has never spent any particular time with a dog. He doesn't
like pets, any of them. He doesn't
like the idea of having one in his house. A clean (not hairy/ not dusty) house is not just a preference for him, it has a direct bearing on his health.
I knew all of this well before I married him -- it was something we talked about explicitly before we decided to get married. I love animals, had always had them, volunteered in a zoo, etc. It was a real blow to think that I might not ever have an animal. But I decided that on the balance, it was worth it.
He knows how important this is to me and has wanted to say "go ahead" many times, but it keeps coming back to his deep-seated dislike. He's realistic about how unpleasant it would be for everyone if he gave in, and then was deeply resentful of the dog because he just gave in rather than having his mind genuinely changed.
The thing is, he's open to having his mind genuinely changed -- he
wants to be able to say, "I personally don't want a dog but I see how important it would be for my daughter and I think the plan for how to make this work is feasible, so let's go for it" and mean it.
But only if he means it.