You need to speak with the airline about regulations and guidelines for traveling with animals. They will tell you exactly what sort of carriers meet their requirements. You will also need health certificates for the cats and perhaps some additional paperwork for international travel. Have you checked to see if your cats are going to have to undergo quarantine in France?

Tranquilizers are forbidden by most or all airlines because they can cause serious or fatal side effects at high altitude.

I, personally, would be very concerned about your cats not being given an opportunity to relieve themselves during that long a transit time. And if they do relieve themselves in the confines of small carriers, how will you change their bedding and clean them up safely without risking their escape? You should discuss these issues with the airline and with your own vet.

You really need to do your homework on this one - with the airline, with your vet, and with the French authorities (regarding quarantine). You may decide that it's in your cats' best interest to find someone you trust to foster them for the 7 mos that you will be out of the country. In any event, you're very wise to have given yourself plenty of time to make whatever arrangements need to be made.

Laurie

The airlines won't let you take your pets if you use tranquilizers. Other than that I don't have any advise on how to make flying nonstop from seattle to paris pleasant! Good luck though and may the force be with you.

Try feeding your cats in the carry ons before you go. Note I dont suggest using tranquilizers unless you absolutely have to - they can prove to be dangerous when mixed with to much stress stimulation and altitude. If your animal is in distress you need to know about it.
I would suggest you put the cats in the carriers and take them out for a spin now and then, before you go - see how they do. Leave them in the car (under favorable weather conditions) while you are shopping. This way you can determine if they will be really vocal or will settle down after a bit. I would get to the airport early so they can get use to the sounds around them. Always have some food and water nearby, a little food will keep your cats content, and lots of water as airline travel causes dehydration for people - You can line the bottom of the carry on with some towels, and have some more stashed nearby in case of accidents - bring an empty plastic bag for soiled towels. I would think it has the same cause in animals. You can find out if there is a place where you might be able to take your animals out for a pit stop on your lay over, get them use to harnesses and a leash and let them out to stretch their legs - this is commonly done for service dogs. The airport you are laying over with might be able arrange this for you.
Good luck

Be sure to check with 'all' the airlines you'll be flying and see what restrictions they have, and paperwork they require, for pets traveling with passengers.

The longest flight I've taken with a cat was 12+ hours and she did fine. For the 3 hour drive to the airport she cried most of the time but once we reached the airport we never heard her again.
I've taken birds, cats and small dogs on planes and I've found the noise of the jets and everything else causes them to become withdrawn, quiet and sleep most of the time. Most of my pets wouldn't eat, drink or do their business (when we used to be able to take them outside!) while at the airport.

Be aware that you're taking an extremely long flight with a layover and it could be even longer depending on weather and delays.
What I'd do is carry-on a small tray that could be used as a litterbox and a small bag of litter. Before the trip I'd find out if there is a lounge (or extra room) that you can use once you get to Paris and get permission to use it to take your cats out of their crates. While in the lounge you could let the cats out on a leash, place the litterbox in one of the carriers and let them have the option of using the litterbox. My guess is they won't use it due to being in a strange place, but it's worth the try!
Getting them used to a harness before the trip will help in handling them, especially if you're asked to take them out of their carrier during the security check (been there!) If you feel the animal is an escape risk, then ask for a private room for them to do their security check.

When traveling with my pets, I always fed them before the trip and then allowed enough time for them to poop and pee before they were placed in the carrier.
I like mazer's idea of the extra towels but another thought is use 'pee pads' since they'll absorb yet prevent the urine from running out of the carrier. They would also be disposable.

I have checked with the airlines and with France re shots, etc. and will be following those rules. No quarantine is required. I was just wondering if anyone had taken their pet on a long trip. My daughter took her 12 year old cat to Okinawa without problems (although she went in checked baggage - something I would never do). She carried a small amluminum cake pan and litter and the cat used it once they got to their destination.

Thanks for your suggestions. I have thought, very briefly, about finding a foster home but don't know of anyone who does not have pets that would like two (and it is not thinkable for me to place them in a home with pets.) Are there any organizations that are available to help out. That is my last resort. If trying to take them on short trips of a few hours doesn't work out, then I'll look into foster homes. They go to the vet in a hard-sided carrier so the soft sided ones will only be used for travel-related purposes (don't want any bad associations).

I believe how a cat reacts to a car trip vs a plane trip will be totally different.

If you want to really see their reaction to the sounds of the airport, take them there in the carrier they will travel in. You should be able to walk around a good portion of the airport with them (of course, not the gate area), but try to take them to an area that has the noise of the planes to see their true reaction.

Just an interesting note: I know things have changed but about 12 yrs ago I discovered some of the european airlines had a different set of rules for pets (compared to US airlines) when a friend's son and DIL flew from Calif. to Germany with a Lab puppy.........in their arms!

Tip: Don't dote on them or talk to them while at the airport.......stay calm about everything and act like it's normal and they will do the same. When walking thru the airport, I use a lightweight towel and keep the carrier covered so that the pets can only see out one side/end. Seems to help keep them calm.

Have you thought about getting a renter/house sitter during the time you are gone and leaving the cats at home? I teach every few years for 5 months in Rome, and I have always rented my house during that time, leaving my two cats comfortably in their familiar setting. If you have a local college or university, graduate students are often a good bet for short term rental. I, for one, would never subject my cats to overseas travel. I think they'd go ballistic.

I have nothing to add. Just wanted to say 'bless your heart' for being such a responsible and caring owner.

annz - thanks for the suggestions. We will take them to the airport to see their reaction. At least we have lots of time to try different things.

Unfortunately, no grad schools nearby - just a community college. Lots of avenues to investigate. It's hard to imagine being without our two little girls for seven months. But their well-being is primary.

Your babies need to be with you and you sound like your doing everything right. Keep in mind it's less than 24 hours that they will be uncomfortable...do able if not pleasant and perhaps there will be no issues anyway.

A good friend of mine travels to France every year for about 7 months and takes her cat with her. As far as I know she has never had any problems. Cats are able to "hold themselves" for very long periods of time, and will probably not need to "go" (although that is not guaranteed)

Do NOT give them tranquilizers. You might try a little Bach's Rescue Remedy, available from the health store as a very mild natural sedative. Just add a couple drops to their water.