There is really no particular breed that can be said to be unsuitable to use a soft-sided crate; it all has to do with your pet’s training and size. If your pooch is calm when left in a crate – she does not chew, dig, or scratch, and practices good bathroom manners, then she may easily settle into the crate life.
Also, your pet needs to fall within the small, medium, or large size bracket because you may not find a suitable crate for an extra-large pooch. If you have a Saint Bernard, which is an extra-large breed, you may have some difficulty in finding the right size for her.