Killing animals in Dishonored: will that ruin achievements?

Can I kill animals, such as the dogs, and still get the achievements? I'm looking at one achievement that says I can kill "no one". I'm not sure if that includes the animals or not.

From the "Notes on Stealth Detection, Chaos, and Trophies/Achievements" post in the Bethesda forums by Gstaff, a Community Manager at Bethesda:

How does the Chaos system work? How do I raise or lower the Chaos level that is displayed on the end mission stats screen?

• Rats, Hagfish and River Krust do not raise Chaos if killed. They also do not count towards detection of your character.
• 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”.

Note that by "does not raise or count towards Chaos", it is also meant that they will not count as a kill. This is because the more you kill NPCs, including Weepers, the more you increase Chaos.

Well, I went ahead and killed some of the hounds...and I still got the checkmark at the end reading "Didn't kill anyone". So my strong suspicion is that the hounds don't count for the achievement, either.

As mentioned in this answer killing animals does not count against you. Except weepers, if you consider them animals.