In order that your dog associate his crate with comfort and security, it is important that his initial experiences be pleasant. Rather than simply putting your dog in his kennel and expecting him to “get used to it,” spend some time helping him to gradually become accustomed to it and you will be rewarded with a dog that not only tolerates but also enjoys time in his crate.
Begin by allowing your dog to explore the kennel on his own. Leave the kennel with the door open and place some food in it to encourage your dog to investigate. If your dog seems very hesitant to enter the crate, even when treats are in it, place his food bowl just in front of the kennel, then right inside the doorway and then, finally, in the back so that he can become gradually acclimated to the experience of stepping in and getting his food whilst in the crate.
If you are using a long-term confinement area (such as an exercise pen or bathroom) to potty train (in which case you will have pads or a paper down), the crate in this area when you are not working with your dog in the living room or other area of the home on his crate training skills. In addition to his meals, also put a couple of toys in the crate. Additionally, toss in a few tasty treats whenever you pass by and he is certain to be going in and out of it within hours if not minutes!
When your pup will enter and exit willingly on his/her own you are ready to begin teaching him to be comfortable being confined to the crate for very short periods of time (to begin).
You will be most successful if you make your first attempts at crate training during periods when your dog is most tired. The first confinement session should be after a period of play, exercise, and elimination (i.e., when the pup is ready to take a nap).
Sit by the kennel and toss a treat in so your dog enters it. Close the door for just a few seconds. Don’t try to push this first confinement period to see how long he will tolerate it. Close the door for just a couple of seconds. Then open it and wait for him to come out. When he steps out of the crate ignore him. You want to instill the idea that release from the crate is far less rewarding than time spent in it (where he gets toys and food). If you praise your dog profusely when he comes out of the kennel it is likely he will view coming out of the kennel as more rewarding than staying in it.
Repeat the exercise and gradually (very gradually!) increase the time the door is shut. Every dog is unique and will require you to go at a different pace. There is no need to race to the finish line in regards to any area of teaching your dog. The slow and steady route is actually the one that is best advised for long term success.
You may choose to put a command word or phrase on going into the kennel. Teach your dog to go into his/her kennel when you say the chosen term, such as, “Kennel up,” by saying it as you toss a treat into the kennel. Later on, your puppy’s toy or ball can be substituted for the treat. Most puppies learn very quickly that “kennel up” (or whichever cue you use) means a treat or toy is about to appear in the kennel, and they’d better rush in there.