However, it is also entirely possible that your dog may be refusing to eat for other, less medically urgent reasons. If that is the case, then it may be several days before she resumes eating. How About More Behavioral Reasons? Often, refusal to eat is a chosen behavior for a dog. Usually, we refer to this as simply being picky. Some people might even call it being spoiled or bratty, but pickiness is usually a learned behavior, so we have to keep our own accountability in mind, as pet parents.