Hey, There's a couple things that don't seem to work right with Killer Vegan, for example, throwing weapons do not incite the fallen vegan debuff, and some animals follow you as if going to attack, but are peaceful because of the trait, and animals fighting for you as well as zombies attack other animals, and do not incite the debuff (Not sure if that's intended.) I'm not sure if these are because of a few mods I have installed, but as far as I know, they wouldn't tamper with the AI of the creatures ingame. Not sure if this post is in the right place, but I hope so.
Those are normal behaviour for vegans in Dredmor. Melee attacks only for debuff. The more annoying problem is animals blocking your movement if you don't have them charmed...