While I'm sure there are definitely breeds that do better and worse than others, I think it's also a total dog to dog situation. I wonder, if you're able to pick from a litter, if you could see how they react to, say, a cat or something small like that?
We lucked out, I have a mastiff/great dane mix, Australian shepherd/cattle dog mix, and neapolitan mastiff. They've all been angels. The first has always been totally obsessed with small animals (would hover drooling over my mil's cats, my brother's hamsters, etc) and has even been known to crush mouse skulls...but he's never been a killer....just a chaser. He even snapped at the chickens when they were chicks....not in a nasty way (I know that's hard to believe, but I know my dog). Now they are all in the yard together, and everyone gets along perfectly. The neo even goes and lays in the sand in the coop with them to stay cool. They ARE all older (8,14, and 5, respectively) but I never thought I'd be able to have everyone in the yard together.
So, like I said, maybe if you had a pick from a litter, test them? Maybe they'd even let you bring a chicken.
We also really lucked out that we watched someone's 4 meat birds for a few days.....we let the dogs have some 'practice' since they were gonna get eaten a few days later