Not from the Ozarks but this caught my eye because we had something similar up near the North Pennines a few years back. Not a howl exactly, more like a drawn out wail that would drop in pitch at the end. Nothing like a fox, nothing like any dog I've ever heard. My mate who's a farmer basically laughed me out of his kitchen when I described it.
The thing with these sounds is people always jump straight to "big cat" or some undiscovered canid but honestly the frequency of these reports across completely different continents makes me wonder if we're dealing with something that doesn't fit neatly into the cryptozoology box.
Anyone managed to record it? That's what always kills these threads, no audio. If you're out there regularly and hearing it, just leave your phone recording overnight. Even a rough clip would be something to work with.