Grief due to the loss of a companion (human or animal)
Arguments among family members
Excessive stimulation (too much play, doggie daycare, dog sports, etc.)
Insufficient stimulation
Too many dogs per available space
Any change in environment (schedule, people, animals, increased noise)
Punitive training (shock, choke and prong collars)
Unreasonable expectations (expected to like all people and all other animals in all situations, expected to be 100% on all the time)
Insufficient social time/family time
Scary events
Humans ignorant of needs and ways of communicating
Frustration
Uncertainty
Excessive play that becomes borderline “obsessive/compulsive”
Not being taught to be alone