The simplest and probably most common way is brute force. Do not make a mistake in believing only big dominant dogs and use this method. If there is a point of weakness in your crate – any size dog can exploit it with some force. One of the most common ways dog’s brute their way to escape is by using their heads to force the bars apart. Cheaply made crates and flimsy metal are susceptible to this.
First, consider your dog’s height, weight, and temperament. The height and weight of your dog will determine whether the dimensions of your best extra large dog crates will work for him or her. Then, consider their temperament. If they have separation anxiety or a tendency to chew on things, you want something that is sturdy and bend resistant. Also, if you have a puppy and want to start housebreaking, consider one of the crates we showed you that have a divider in it to help with the training.
Update: We traveled quite a bit this holiday season and this portable crate was absolutely awesome! I have seen some reviews about bad zippers but suspect it's due to misuse. You have to raise each side before zipping it -- just common sense, people. Otherwise, there is too much pressure on the zipper. I think zippers on this crate are sturdy. Another suggestion is placing your dog's favorite bed inside. The crate (we have extra large) has plenty of room to add an extra large fluffy dog bed our dog loves. Because the crate folds flat, we place the crate in the cargo area and cover it with dog's bed when on the road. The dog sprawls like a queen! :) When we get to the destination, we unfold the crate, throw the bed inside, and voila -- cozy house that ... full review