If you plan to take your dog with you on an airplane, you need an airline approved crate . and you must do your homework before buying one. The term " crate"Â is a bit generic, so let’s start by breaking things up a bit. If you have a small dog, so you can easily use a soft sided carrier, often called simply a bag for pets, and you will be able to keep your dog with you in the cabin. If your dog is big, then you really need a dog cage in hard sided crate or dog and your pet must travel as cargo. With regard to medium sized dogs and large breeds puppies, do things a little more complicated. 
You must be sure to measure the carrier, measure your dog and check with the airline you will use to see what their needs are. Never make a decision based solely on the weight of your pet! In fact, the measurements of your animals are actually more important because your dog should be able to move a bit and be comfortable during the trip. The weight is really more for you. You can have as much weight in a career as you move around the airport? Some airlines have approved dog carriers wheels, which certainly makes them easier to move as you are in transit or going up and down the plane.
But the design of these will be very difficult in the face, making them the largest and latest means they will really be for smaller dogs. If you are willing to pay extra for a place, you can see if you can put the company’s seat next to you, rather than to keep it stored under the seat in front of you. Of course, this would be the preferred choice for you and your pet, but it would certainly be more expensive. And the carrier you choose to still have to meet certain instructions of the airline.