What is the ruling on preventing one animal from killing or harming another?

A person is not obliged to prevent one animal from attacking another unless the animal being attacked is a "respected animal" (hayawan muhtaram), meaning one whose killing is forbidden by Islamic law. Examples include a hunting dog or a guard dog. Whoever is able to save a respected animal from perishing and does not do so is sinful. Scholars have placed the respected animal in the same category as an infallible human being regarding the obligation to defend and save it. It is also forbidden to incite animals against each other.