Definitely not a hot spot! With a hot spot the skin turns red and hot before the hair falls out, then the skin starts weeping and gets raw, this causes the hair to fall out, so you definitely would have known if it was that. When the weeping dries, it is crusty like a scab.
You could have a couple different things going on here. If Bruno is sensitive to fleas, they can remain itchy for up to 10 days after a single bite, so you don’t have to see a flea for it to have been a flea. And then of course there is the drier winter air. It isn’t at all uncommon for short coated breeds to have dry skin.
