The phrase "dog suffering from separation anxiety" refers to a dog that experiences distress and anxiety when separated from its owner or family. This condition is often triggered by changes in routine, such as when an owner goes away for work or leaves the house without the dog. The dog may exhibit symptoms such as excessive barking, whining, destructive behavior, pacing, and even vomiting. Separation anxiety can be treated through a combination of training, behavior modification techniques, and sometimes medication.