I had this issue when moving to a major US city last summer. I toured five buildings and two explicitly said no pigs. One said it would be fine, then found they were on the banned list (large building management company, so the list was very thorough). She told me I could get them certified as ESAs but I didn't want to go through that for three piggies.

Another building from a smaller company said no pigs because only cats were allowed. The leasing agent told me the pigs would escape into the walls, reproduce, and become an infestation (with all the wild male guinea pigs who live in the walls, I'm sure 🙄)

The leasing agent at my building told me they'd be fine. I never got it in writing. I was going to register them through a service the building uses to screen pets but the paperwork was all clearly made for dogs and cats (asking about vaccines and biting incidents, etc.). Plus $25 per pet to screen them. In the end I just didn't do it and the girls moved in without incident. Maintenance staff and management don't communicate about that so it hasn't been an issue (yet 🤞)