This is fear of going outside. It sounds strange that a dog would fear open spaces but it does happen, occasionally a dog is afraid of the outside world (even going out into the garden can be very stressful). Sometimes the cause is known, perhaps the dog was frightened by a loud noise, and sometimes the reason can not be explained.

With the advice given to you during a behaviour session, it is possible to show the dog that the world does not have to be a frightening place. After time and rehabilitation it should be possible for the dog to once again enjoy going out for walks.

Agoraphobia
(Fear of going outside)