It depends on what you mean by "work." If you mean specific behaviors or a set of specific behaviors, that the dog is trained to perform that mitigate your disability, such as guiding, then the dog may be a service dog.
Unfortunately, some people look for loopholes to excuse them from actually having to qualify either as disabled or as having a trained service dog. They try to convince themselves that the training requirement doesn't apply if the dog does something that benefits them, such as getting them out of the house for exercise. However, wishing something doesn't make it so.