Dogs and horses have been part of human society for a long time and they can be trained to some extent but how well did they handle being surrounded by humans (and other animals) fighting and killing each other? Particularly once cannons and guns became commonplace, how did they not run away at the sounds of the explosions?
Hello there. You might be interested in the following answers of mine:
For the question "How did horse riding gunmen navigate through the trouble of not startling the horse with the blast?" I looked at how the US Army trained horses to handle guns, according to an 1862 manual.
For the question "Do we have any information on how horses were trained or conditioned for melee combat?" I gave an overview of some of the sources and methods for training horses in the ancient world.
There is always more that can be said on this topic.