If you plan to take your cat, dog or other pet on a trip, it's best to follow this procedure:

  1. First, find right airline suitable ticket, but don't buy it yet. 
  2. Contact the airline's call center to clarify their rules of transportation for your particular pet.
  3. After that, in accordance with the requirements of the airline, go ahead and purchase your ticket.

By the way, keep in mind that many low-cost carriers do not allow pets onboard. So, plan ahead.