What can I do legally

I have 2 kids and a tiny Yorkie dog. My kids are 2 and 4. My apartment has rules against aggressive breeds. You can't have them so that means no pits. I have neighbors that just moved in above us and they have a pit. I didn't want to confront them so I just went to my office about it and the lady told me "Oh I think it's a service dog." I didn't know pits could be service animals but I'm told if it's a service dog they don't have a choice by law. They are right above me and I don't feel comfortable having my kids outside or my dog because they come out a lot. I'm assuming the "service dog" belongs to the boy but is there ANYTHING legally I could do about this? If not I'll just have to deal but I don't want to be around a dangerous breed