If you're thinking about bringing your pet on your next vacation, think again if your trip involves air travel. It can cost more to fly your pet than it does for your own air ticket.

If you want to bring Fido or Tigger on board as a carry-on pet, you will pay as much as $250 round trip on American, Delta, United and US Airways. If you want to send your pet in the cargo hold, you will pay between $100 and $200 each way on most carriers. United charges by weight, combining the weight of the animal and the kennel, so if your animal and kennel weigh 10 to 50 pounds, you'd pay $219 each way, or $438 round trip on domestic flights.

Every year there are reports of pets dying in the climate-controlled cargo area on planes. Last year, a kitten in the cargo hold of a Delta Air Lines plane was found nearly frozen to death after the plane sat on the tarmac for an hour after arriving in Hartford, Conn. The kitten died a short time later.

Fewer airlines are letting you check your animals at the airport. You often have to go to the cargo center to ship your pet. Many airlines won't allow you to check animals at all, such as Southwest, AirTran, JetBlue, Spirit, US Airways and Virgin America.

There are also embargoes for flying pets in cargo when the weather is too hot or too cold, and certain breeds, such as pugs and Persian cats, are not allowed on some carriers because of potential breathing problems.

Southwest and AirTran have the cheapest fees to bring pets on board, but they do not allow animals to fly in the cargo hold. Southwest and AirTran charge $75 each way to bring an animal on board.

Most airlines have a 25-pound weight limit for the pet and the case for carry-on pets. If you are bringing your pet on board, use a soft-side carrier.

Many airlines limit the number of pets they will transport in the cabin, so make sure you make a reservation for your pet well in advance. You'll need to make sure that your animal's shots are up to date, and some airlines require a health certificate.

Some airlines make you give up your carry-on allowance when you bring a pet on board. So not only will you pay a hefty fee for your pet, you will get hit with fees to check baggage. It might be cheaper to hire a pet sitter than to pay the airline fees.