DEFRA/PETS Information: Travelling with your pet factsheet link

Here is the link for the guidelines for carriers etc..  You should also check with the airline for specifics about their requirements for carriers.

http://www.defra.gov.uk/animalh/welfare/farmed/transport/trans-dogcat.htm

We had to have ventilation on all four sides of the carrier.  Rather than buying a new one, we drilled holes in the back.  that satisfied the requirements. 

I used puppy pads in the bottom of the carrier.  They are absorbant (like maxi pads).  Do not use newspaper.  Also, put in a towel or blanket for warmth.