If you kill a hound (and no one sees you do it), yet they see the dead hound's body, does this raise chaos? I understand that killing it does not, but I am not sure if say a guard sees a dead wolfhound will affect your chaos level. (I REMAIN UNDETECTED THROUGHOUT)
Wolfhound kills do not count towards Chaos, but they can detect your character and will count towards that. They can also discover bodies, as well as their corpse will count towards “bodies found”.
Source: Bethesda Dishonored forums post, "Notes on Stealth Detection, Chaos, and Trophies/Achievements" by Gstaff, a Community Manager at Bethesda Softworks
For more info on Chaos mechanics, see this question: What's the best strategy to keep the chaos low?