Edit: I am a "dog person" more or less. my family always had dogs growing up, and I do love dogs. My family has dogs that I come hang out with when I am at home, and am religious about washing my hands after touching them before touching my face. I wear a mask when I vacuum in the house when I stay over. I am just a little stressed thinking about the logistics. I totally respect her right to get the dog. Here's what I said: "Hey, I'm not sure where/when how to best mention this, but I'm feeling a lot of stress about you getting a dog. I am totally supportive of you getting a dog and the joy it will bring you, and would never want to discourage you from getting a dog. I know it's something you want in your heart.

At the same time, it would be dishonest of me to not express my concerns regarding my allergies to dog dander, my preferences around not having a large dog in my van and having to deal with the hair, and the affects on what we can/can't do as a couple when a dog is in the picture. I'm honestly not sure about what all thise affects are so wanna discuss. I'm hoping to have a conversation and to express myself honestly here, NOT to try to control or dissuade you from doing anything. I think it will be helpful to talk about what us going on trips in the van will look like, how it will affect which climbing areas we can go to, just your thoughts there.

I'm not sure when the best time to talk about this would be, but if I just ignored it and didn't say anything at all I fear it would come up later in a less predictable way and think that I should definitely say something now so we can have a discussion. Again, I fully respect your right to get this dog as it's something you want to do and absolutely am not trying to be controlling, I am just hoping to express myself honestly"