You can make a room request at any time. Call and ask that your request be added to your reservation. They will most likely tell you that they cannot make any promises but your request is attached to your reservation. As far as pets go, I am uncertain but I do know I have seen them in the halls of both Tower 1 and 3. The first time we stayed I was told pets are allowed on the lower floors but not the upper floors but I do not know if that's true or not. When you call, request a non pet room and explain about your son's allergies. They will note it on your reservation.