I have discovered, or rather confirmed a suspicion I had, dunno if it was before, that the negative vengeful thought, stacks per ally involved in a given fight - be it against enemies or wildlife. If you have 10 dwarves and three dogs in a fight against an enemy, they get hit with 12 strength 4 (fairly strong, but not "horrified" level strong) negative thoughts that can send someone from perfectly content to tantrumming in an instant, made worse if it keeps happening (such as by buzzards making repeated attempts on a trade depot, causing everyone in view of the birds when they interrupt someone to get hammered per other dwarf or livestock nearby that can also see the birds.)
I found this out when a bunch of buzzards attacked my depot and I suddenly had three haggard dwarves despite them not being the ones attacked (the one who got attacked was a kid who proceeded to break one's neck and slam another into a roof so hard by its wing that it's lower body split in half,) and them floating at 0 + or - 1-200 stress for several years.
I can also confirm dwarf children are bloodthirsty psychos who will relentlessly try to kill anything and everything not belonging to thier home that shows even the slightest ill intent - from werebeasts that tower over adult dwarves, to harmless buzzards, to giant badgers that rage and go for them, to invaders.