I diagree, Bill. I think that when dogs act "protectively" towards children or adults in their owner's family, they are being instinctively protective towards members of their "pack". Dogs aren't stupid, and they can pick up what is allowed and what is not, what is dangerous and what is not, within the group, at a certain level. They then apply that knowledge without, I think, a great of reasoning when those situations arise.
Elsie, my shepherd bitch, attacked a completely innocent tradesman at my parent's house one day simply because he got between her and my niece, towards whom Elsie was very protective. Fortunately, only his dignity was injured.
Dogs will also put up with things from kids that they would never take from an adult. Elsie loathed anyone tugging on her ears, including me, and we were very close. She'd growl at first, but if you persisted, she'd take your hand in her mouth quite firmly - not a bite, just holding on - and growl again. After that, all bets were off. My niece, on the other hand, when she was a toddler, could sit on Elsie's back and twist her ears like the twistgrips on motorcycle handlebars. The dog's eyes watered and she whimpered, but she didn't try to escape or growl.
The reason I raised that quite serious question about animal altruism in my post above is because cats don't have the same instinctive "involvement" with other cats, never mind humans or dogs, apart from their own kittens. And even that instinct becomes suppressed when the kittens are weaned and reach a certain age. I've seen a cat attack her own, grown, kittens when they got between her and her food. The recognition of kinship ends with kittenhood.
So what would motivate a cat to provide a dog (who appeared poorly) with food? This was a real incident, and I'm glad that Frank was staying with us when it occurred because otherwise I doubt if anyone else would have believed it.
