When the weather got truly miserable last week, I was worried about keeping the dog warm... he has a coat, but it leaves the back of his neck fairly exposed. I rummaged around in the cupboard and found a Noro cowl I'd made for myself a few years ago, and slipped it on him. He fought it for about five seconds, but then decided it wasn't such a bad idea after all. It didn't stay up over his ears, but I figured even a little protection was better than none.
(It's the sadly discontinued Silk Garden Chunky, about 18 inches in circumference, a bit of (k1, p1) ribbing at top and bottom and otherwise just stocking stitch.)
So it turns out that hound-cowls is actually a thing. They're more applicable for dogs in the Greyhound family, who have long thin necks and very little body fat... Dexter's neck is neither long nor thin, and he's doing fairly well on the body fat thing, but the shape of his coat does leave a good bit of him exposed.
After doing a bit of research - ok, doing a Google Image search for dog cowls, which is an excellent way to spend half an hour on a cold day - I decided that it wasn't unreasonable to make him his own, more snug so it covers his oversized and delicate ears.
This free pattern on the bromeleighad blog seems like a good place to start, and I love the photos.