A variety of combat encounters involve fighting wild dogs and wolves. The optional quest "Winter Wolf Pelts" tasks the player with fighting specific wolves for their skins. Another optional quest, "Albert and His Dog" has the player encountering a child who asks them to find his lost dog. This can be completed without harm to the dog if the player keeps the provided quest item in their inventory. Without it, the dog will attack.
There is a quest titled "Drienne's Cat" that tasks the player with finding a missing house cat. Unfortunately the cat has always perished before you find it. Depending on the player's in-game reputation, the owner may blame the player. The Enhanced Edition of the game awards an achievement with an icon of a cat skull.
One of the companions' banter lines heavily implies he has (presumably killed and) taken the eyes of elves to gain their infravision. Unsuccessfully. I haven't seen it happen on-screen though.