Same experience as others regarding dogs. Portland to Sacramento (turned inland at Bodega Bay) in 2008, zero dogs. Not one. As far as shoulders, Oregon was great, California less so. I seem to remember two climbs just south of Crescent City on 101 with zero shoulder, winding roadway. Keeps the heart pumping. Much of Hwy 1 is also shoulderless with lots of curves, ups and downs. Despite all that, had zero problems with traffic, other than there being too much of it (summer).