[gushogg-blake]

Hmm, semi-wild dogs seems less likely to me as they'd have to hang around settlements to get food, in which case they'd get noticed and dealt with. Unless you mean they can hunt in packs and take down sheep?

[boomboomsubban]

Dogs are capable of hunting small game, as well as eating things like berries. Or maybe they hadn't been there that long, just longer than a day.

From my perspective, I'd assume dog until I got overwhelming evidence it was a big cat. There are far more dogs in Britain than big cats for a start.