No matter what you plan to use a pet carrier for, they certainly come in handy and can sometimes be necessary.
Sometimes walking a small pet isn't an option, so a comfortable carrier can make things easier for both of you. A soft-sided carrier is a great option for any pets less than 20 pounds. The mesh walls allow pets to watch what's happening around them, and provide proper ventilation.
The soft carriers are not recommended for air or train travel, through. They do not offer enough protection from the jostling that is inevitable while using mass transit.
If you are forced to evacuate pets in an emergency, or your pet is traveling by plane in cargo, you want to use a solid body plastic crate that is large enough for your pet to stand up and turn around in.
Small pets allowed under your seat near your feet are best protected by a hard plastic and metal carrier. Remove water and food bowls, but be sure to place a worn t-shirt or pillow case in the carrier with your pet for the trip.
Your scent will help calm them if the trip gets a little bumpy. Check your airline’s website for their pet travel requirements.
Also, be sure to check doors, zippers and other closures to make sure they are secure, and your pet won’t slip out, run away, or become injured.