Dogs (excluding racing greyhounds and banned breeds), cats, rabbits, guinea pigs, domestic fish with no aeration requirements (not intended for resale), and domestic birds (maximum four birds per cage) that do not need a permit to travel.
The right crate is like Business Class for pets
Airlines use measurements relating to the pet’s size to make sure there is enough room inside the crate for the pet to travel comfortably, with enough room to stand, sit and turn around.
The dimensions shown below should be used for the internal measurements and should be used as the minimum required.
A + ½ B = Length
C = Height
D x 2 = Width