You will need to measure your pet from tip of nose to base of tail (A) and from the top of the head to the ground (B) when your pet is standing erect. (tip: use a piece of string, then measure the string) Compare these measurements to the interior measurements of your carrier. Your pet's measurements should be slightly smaller than the carrier measurements. If you need an extra bit of height, the will give you that.
Extra Small Pet Travel Carrier, Red - SHOP IRIS USA
IRIS Extra Small Pet Travel Carrier: Well-ventilated and designed to meet travel requirements Attachable food/water tray included Accommodates door padlock Easy to transport Dimensions: 18.11"L x 11.42"W x 11.22"H
Extra Small Pet Travel Carrier, Navy - SHOP IRIS USA
COOL! Small pet carrier has a fold-out room on the side for 64% extra space! Great for long traveling situations in which your pet has to spend extended time in its carrier. AND it has a top-loading opening--which I think is ideal when you have a reluctant cat to put inside. Brinkmann Small Smart Space Carrier $69.99
Suncast Pet Carrier - Extra Small - Sam's Club
The material from which the dog carrier is made should be sturdy. Not only does the carrier allow owners to carry their small dogs and keep them from escaping or wandering loose in a public area, but it also provides the pets with some level of protection in case of impact or jarring. In an airport, the carrier protects the dog from being struck by a heavy or from being stepped on by hurrying travelers. In a car, it keeps them from being thrown into the front seat or through a window if the driver has to stop suddenly. Many carriers are made from thick, sturdy plastic, while others are made of metal or wire. Wire carriers are not appropriate for airline travel, so most airlines require a or carrier instead. Some carriers for very small dogs may be ,, include extra padding, and resemble carry-on luggage. However, these kinds of carriers are not always permitted on planes and do not always offer sufficient airflow. Whatever its structure may be, the carrier should be stable and balanced, difficult to tip or knock over.