Whenever my friend Monica would leave her home, her 17-year-old Corgi-mix Chuck would go out the doggie door to the backyard and howl until she returned. The situation was stressful, and Monica would worry as Chuck would remain outside for hours in the Texas heat. This progressed to the point where a neighbor suggested it may be "time to consider putting him down."
Chuck is a sweet dude. I discovered that Chuck had been through some big changes in 2015 with a family member moving out and his dog friend Ruby passing away. This was when the howling first began. Due to these changes, Chuck was most likely stressed and grieving. After three sessions, Monica reported to me that he had completely stopped all howling and that he seems more mellow now. She said that he'd always been an anxious guy but now his anxiety levels are way down. Monica also said that she's pleased that, even though Chuck still has access to the doggie door, he stays indoors more where it's much cooler instead of hanging out in the yard.