Months and months of research went into this move, not just for us, but also for the cats. Plans I had originally made for transportation fell apart, but our basis remained the same. The cats must fly with us in the cabin of the plane. The cats would not be quarantined. The cats would stay with us throughout the trip as much as possible. Flying with the cats in the cargo hold wasn't ever an option and our route was actually cheaper then if we had flown directly to Glasgow with both cats in the cargo hold.
Our original plan was to fly to France and drive up to Glasgow (since the UK does not allow pets to fly into the country in the cabin unless they're service dogs), but a one way car rental from France to the UK would cost over $1600. We began looking at other options, since we already had a plane ticket that would take us to Paris. Eventually, we discovered that Stena Lines was the only ferry that would accept foot passengers with pets to the UK, and they left from Hook of Holland in, you guessed it, Holland. We thought about it a bit and decided to bite the bullet and switch tickets and fly Atlanta to Amsterdam, via Lufthansa with a two hour layover in Frankfurt, and then rent a car to Hook of Holland (although one can take a train with pets but it wasn't practical with the amount of luggage we had).
To prepare for the trip, in June and July we had both cats microchipped and vaccinated against rabies (again). Meanwhile, I was valiantly exercising Fezzik because he's a bit of a chunk and there are weight limits as for pets carried into the cabin. (For most airlines, that weight limit is between 7-9kg.) Eight days before we left we went to the vet and she completed all the paperwork for entering the UK and Europe. Four days before we left we drove down to Columbia to have all the vet paperwork certified by the USDA (which took 3+ hours.) Two days before we left I went and picked up their kennels, and doused them with some soothing spray and catnip with lavender. The day we left we fed them a light breakfast, gave them some water and then put all their food away, but kept the treats in easy reach. (Both cats are fed 2 meals a day so this wasn't really anything new. I was more worried about the cats getting sick on the plane and had been advised not to let them eat too much before they flew.)
We took them to the airport, had their paperwork reviewed at the counter, and together took them through security. We asked for a private room for the cats and their carriers to be examined (because I had fears of Bitty running away in the Atlanta airport, which has actually has happened...) The remainder of the time, the cats were in their carriers. Generally, I carried the Bitty and Aaron put the Fez atop the small rolling suitcase and so he traveled in style. ;) At takeoff, the cats were at our feet, but there was an empty seat next to me, so I put the Fez on the seat and covered up the top with a blanket, buckled him in and no one was the wiser (he's a needy cat and unlike Bitty, wouldn't try to escape when we unzipped the carrier to pet him). We fed them treats on the plane and gave them water once we landed in Frankfurt. We would stick our hands in the kennels and pet them and love on them, but the remainder of the time, they slept quietly. For both flights, we sat in our seats until everyone was off the plane, to avoid smacking some poor person with a 14 pound cat and carrier. After taking a 7 hour flight with two cats, sandwiched between two rows of screaming children, I determined that flying with cats is actually easier and quieter then flying with kids.
We stayed one night in Amsterdam, which gave both cats the opportunity to run around the hotel room. Then we packed them up the next morning and drove to Hook of Holland for the ferry. Stena Lines was amazing. We got there early and the supervisor went over our paperwork for the cats to approve them entry. Of course, while we were there, we realized the vet had put down the wrong year for Bitty's birth and I had about two minutes of freaking out before I realized that she was going to let them through. Aboard ship, the cats had their own kennels for the 5 hours or so that we were on board. We rented a cabin with a bed and a bathroom and it was the only time we were separated from the cats the entire trip. We could even watch the cats on the tv and we went down and visited them from time to time.
Once we landed in Harwich, England, we got in our rental car and drove through the night. Both cats loved sitting in the back of the car, watching the cars go by. Both cats are trained to ride well in the car outside of their carriers and they enjoy it best when they can see out the windows. We all had a whiney session about twenty minutes outside of Glasgow, but once we got in to the hotel, everybody was so, so happy.
Both cats have adjusted well to life in Scotland. I was initially worried about the time zone changes, because both cats are insistent about being fed at 9:00pm and 5:00am, but the time changes didn't seem to affect them. Once they got in and slept for a few days, they started right back up again with meows for food at 9 and 5. Because we packed only a small amount of food and cat litter, we had to purchase new brands once we got to Glasgow. Both cats adapted to that change exceptionally well, and we were fortunate to find a pet store nearby that sells a similar type food to what they were used to.
I know we were lucky traveling with two cats and a massive amount of luggage and very minimal problems. Moving to a different country is stressful anyhow, but compounded by two cats and various other issues, it could have been, and probably should have been a recipe for disaster. Fortunately, we were surrounded by helpful flight attendants, Lufthansa employees, people at hotels, people in customs, and helpful people in buses, trains, planes, and car. We may have had to route our entire trip around the cats and I wouldn't do it any other way. :)