And shipping. Shipping or travelling with any animal can be fraught with complications. In our case we were lucky that Switzerland, unlike the United Kingdom, doesn't require a quarantine. But there's still lots of paperwork, getting their vaccinations up-to-date, checkups by their regular vet as well as a European Union-certified one, microchipping... And all sorts of detailed rules regarding kennel sizes and weight regulations and so on.
Only once you've passed them to the loaders at the airport is it all out of your hands. Who knows what happens to them down there? Or on the plane? There was quite a bit of turbulence on our flight (lucky they got to travel with us as "excess baggage" and weren't shipped as cargo on a different date). When we picked them up, their water dishes had been spilled all over and it was none too clean inside the kennel. The cats themselves were warm and dry though, and when we finally got them to our apartment hotel they didn't seem any the worse for wear. Their appetites haven't returned to normal but besides a bit of mewling, they seem to be settling in.