How to prevent a dog from defecating in its crate<br>Make sure the crate is the right size. Oftentimes, dogs will defecate in their crate if it's too big. If the crate is large enough that your dog can comfortably poop in a corner he might choose to go in his crate rather than wait to be let out.
Dogs probably won't poop in the corner of a small crate.
If the crate is large enough that your dog can comfortably poop in a corner he might choose to, so if the crate is small, he can't comfortably do so and will probably choose not to. The model doesn't follow the logic.