But in Europe, they didn’t domesticate them to be a food source.
Dogs were domesticated in many places around the world, and at different times. There is still some attempted domestication going on with foxes and wolves in scattered places around the world, and dogs are not of one source, either wolves or foxes, but in many instances of crossbreeding between several subspecies of both foxes and wolves.
And who says that Europeans never turned to dogs as a food source. Depends on how scarce protein sources are through supply channels. A LOT of dogs went feral.
Still do.