Southwest Airlines has the following policies on pet-travel:
Pets are allowed as carry-on only. Restrictions vary for UK and US-based animals, so please refer to their website.
Fees: $75 each way.
– Only cats and small dogs are allowed on as carry-on.
– One pet carrier per customer, with a maximum of two pets of same species per carrier.
– Does not require health certificate from veterinarian or vaccination records. However, upon arrival, states may require this information.
For complete guidelines, check their site at: Southwest Airlines