Just thought of a p.s.
I had carry on just for the dogs...in it I had pee pads, food, extra leashes, extra harnesses (I bought water when I got through the security check as you can't bring in water in bottles), a few paper towels and regular small towels in case any of them had an accident or threw up.
The whole going through the security check wasn't fun, but if you speak up..they are pretty good about helping you through.
Debbie