If it's really, really, reallllly bad in front of that window then I would place an actual physical barrier in front of it for a good while so that he has to go without it and readjust his behavior.
But as far as Composure...you could certainly try it - theoretically the L-theanine should help a bit, but I really don't know that it'll be all *that* effective when a dog's emotional/mental state is super keyed up, ya know? In those states, something more powerful is often needed...
__________________ ~ A friend told me I was delusional. I nearly fell off my unicorn. ~
°¨¨¨°ºOº°¨¨¨° Ann | Pfeiffer | Marcel Verdel Purcell | Wylie | Artie °¨¨¨°ºOº°¨¨¨° |