I just read posts in this thread and am a bit surprised that in this day you would consider sneaking anything on a plane-- no less live animals.
We traveled to Chicago with our cat a few years ago-- long before 911-- and they made me take the cat out of the crate. I was so afraid to do it because he was a very nasty cat and we had to sedate him for the trip, but. I didnt know if it would really have any effect on him.
The security person took him herself and checked his belly-- I had visions of claws, scratches, blood and a wild cat loose in the airport. A trick of drug trafficers is to operate and fill the abdomen cavity with drugs. All went well, but my heart was bounding.
Post 911, I would not dream of trying to take anything on board that I was not allowed. Also, consider what you would do if they did discover your extra dog -- coming or going-- how would you travel?
I recommend finding someone like me-- who has a private home boarding business. I have two little yorkies myself and would never consider putting them in a kennel, I board them with a lady who does provate home boarding.
Interview and visit a home boarder long before you travel. You could even leave your dogs overnight a time or two as a test run. Take a look at my website to see the kind of things you should look for--
http://www.doggienanny.com
You can find private home boarders through your vet. They usually have a list on hand. We home boarders love dogs and spend lots of time with them. I think some of them get much more attention with me than they get in their own homes! One thing to consider is the size of dogs a home boarder caters to.
Good luck.
Linda
the doggie nanny