The size of your dog is very important. Your puppy may spend several hours inside the enclosure and should feel protected, not trapped. A training crate must be well ventilated and kept clean.
Ideally, the container should be just big enough for your dog to stand and turn around. (There should be 3 or 4 inches above the dog’s head when he stands up.) If your puppy is still in the growing stage you may want to consider renting a kennel in order to “trade up” to more appropriate sizes as your pet develops.
Like a Den
Domestic dogs are only a few genetic steps removed from their ancestors: wolves. In the wild, these animals raise their young, sleep and are protected from danger in dens. Using crates for in-home training reinforces your pet dog’s natural instinct to seek safety and comfort in a small, enclosed area.
Dogs do not typically soil their “dens,” so crates limit the animal’s access to areas that are off limits. They provide a certain amount of control while your puppy learns acceptable behaviors during house-training.
In the video below, from the American Animal Hospital Association (AAHA), Lisa Mazzaferro, DVM, explains why crates are ideal for puppies in a new home: