The term Separation Anxiety is broadly used to describe a variety of problem behaviours that are seen when a dog is left alone. Most often these behaviours are symptoms of a fear of being left alone but they can also manifest in dogs that are frustrated and suffering from a bit of FOMO. For this reason, you might also hear people using the term Separation Related Problem Behaviors, as it's often a more accurate description. Typical behaviours you might see include, but are not limited to;

• Vocalisation - excessive barking, whining, crying and howling
• Destruction - chewing, scratching and tearing up of furniture, carpets, doors and walls (particularly around entrances)
• Pacing and Panting- This can start when you're getting ready to go out and haven't even left.  Once you have they move quickly between doors and windows looking for a way out or for someone to return
• House Soiling - particularly when the dog is usually housetrained.