Now that we can do this... maybe also raiders could do this? Add some raiders or raid types which have dog owners (about 2-3 dogs per person) and use them.
Melee users signal them to attack when raid attack starts and ranged users use them for defense. Animals will rush to avenge their owner if he is killed.
Possibly not every raid should have this aspect. Probably distinct faction could be created and only that faction uses animals for combat.
Also lone strangers passing by could have some animal accompanies :)
Imagine a group of tribals unleashing a set of dogs on your colonists? Wicked.
Dogs are some of, if not the, "oldest" domesticated animals. They should really be prevalent.
No. Imagine a tribal raid spearheaded by Elephants!
This could be the solution to the whole "So many tribalmen attacking your camp the game nearly crashes" problem we've had for so long: If we can replace some of the attacking tribals with animal handlers with attack animals, we'll have an increased variety of challenges within the same event, while cutting down on the absurd size of the raids. I like the idea of Elephants and Rhinos in particular because they could absorb a ton of punishment before going down, thus distracting you from the angry human horde right behind them.