Interestingly, veterans considered their service dog's untrained behaviors (such as companionship, happiness, and love) to be more important than the trained behaviors. They greatly benefit the mental health of veterans with PTSD and can have a therapeutic effect. These untrained behaviors are also characteristics of typical household pet dogs. However, it is important to note that pet dogs do not have the same effect on PTSD as trained service dogs do. Pet dogs helped their veteran owners with PTSD to feel less lonely and depressed but did not have an effect on symptoms such as nightmares and flashbacks.