Whether you should stop a cat fight depends on the situation. If two cats are playing and fighting, then there is no need to stop it. If the two cats are fighting fiercely, then it is best to stop it to prevent the cats from appearing. Injury situation. Generally, cats will yell, have airplane ears, have dilated pupils, open their claws, etc. when they really fight. When you find similar situations, you can use snacks, cat teasers, etc. to distract the cat, or you can reprimand the cat loudly.