I've never done this, but I moved to Italy from Chicago last year and I know people who have brought their pets over. First of all, with a cat you can carry them on the plane with you provided that you have the proper carrying case and buy them a ticket. You'll have to check with your airline for specific rules and costs. Otherwise, you will need to visit your vet within a week of your departure and get a certificate saying your cat is healthy and free of rabies in order to bring them into the country. Check with the consulate of where you're heading to - there should be one in Chicago) for the best info on all the documents that you need. If I were you, I wouldn't use a pet shipping service, seems like there is too good a chance that something could go wrong. And putting them in the cargo hold of the plane can be mean. Get good advice from your veterinarian. Good luck!

Whatever airline you decide to travel with make sure you know what the rules are because some airlines no longer take pets in the cargo and some don't allow pets in the cabin for transatlantic flights. Check with your vet - they may be able to offer you some good advice.

nope i have never done that before.. my sis tried once but i dont know why she was denied by the airport authorities..

She was travelling to London

Depending on the airline you are travelling on, you may be able to take the cat in a suitable carrier in cabin with you.  There will be a charge to do so.  Most times there is a limit to the number of pets in cabin, so you will want to make sure there is space prior to booking your ticket.  Once your ticket is booked, call the airline and add the cat to the reservation.  Otherwise, the cat will have to fly in the cargo hold.  Airlines will often have an embargo for animals travelling in the hold when it is very hot or very cold or very busy. 

Your cat will need a valid vetranary certificate with details of owner, identification and vaccinations, needs to have up to date rabies vaccinations and be tattooed or microchipped.  The pet carrier will need to have the owner's name and address in Italy.  Once you're settled, you can see an Italian vet to get an EU pet passport if you want to travel with the cat through the European Union.