What do you need for your pet to travel with no problems?

its depending on a cat/dog/mouse/guinea pig. guinea pig's or mice shouldn't be a problem just simply get a portable cage and fill it's with anything the other cage had. if it's a cat its up to you. if you feel your cat might be a bother to others you would put them in the luggage compartment. if its a dog SORRY it would HAVE TO be put in the luggage compartment. ALWAYS fill cage or carrier with news paper water and food.