Earlier quoted context omitted.
A horse or squirrel will kill and eat a bird if hungry and given a chance. Sounds pretty violent to me.
Why do you mention violence? I've never seen or heard of what you describe. Horses are herbivores; can they digest meat? Can they chew it? Squirrels reputedly eat nuts.
You have the whole internet in front of you, find some links.
If you're still having trouble in 3 minutes, come back and I will provide some. There are tons.