Almost all pets can be sent by aircraft, but the rules vary from airline to airline.
Some companies only accept cats and small dogs in the cabin, and then only in small cages or waterproof bags.
Other companies do not allow rodents on board, not even in the hold. The rule of thumb is that all animals must be stored in separate crates when sent in the hold.
It is therefore important that you consult your airline well before departure. You will find more information on the airlines’ websites (see links to the right).