My muttly chicks were pretty hands-off... but now that they're a few weeks old, they follow me everywhere. They're into everything I'm doing. I keep an eye on them, watch where I step, and they're fine. I'm happy to have them comfortable with being handled. They roam under, around, and over the top of my dogs when they're out there. But let any strange dog show up... and there are screams of alarm from every direction, with flying chickens headed into the run, into the coop, or - in the case of the chicks - on top of my feet. Apparently, I'm a mama hen, regardless of gender, and they view me as their protection. I don't think that making them into pets makes them less capable of identifying danger - it just means that they exclude some usual threats from what they consider dangerous. Like... my border collie mix.
Border Collies x Fowl is usually BAD, from everything I've gotten from people who have both.
Mouse x my EE's = Hilarity.
They were NOT raised as pets. They were raised hands-off, and I got them as well-grown pullets. The person who I got them from didn't have dogs, so they weren't used to them. But the first time Mouse ran through the yard, she had Snow right on her tail... I'm not sure if Snow thought Mouse's fluffy white butt was another chicken, or what, but Mouse tucked tail and RAN. Ever since then, every time she runs past, she has three EE's running with her, cackling gleefully. They have no fear of her, she has no aggression toward them.