The main reasons dogs and cats clash are mismatched personalities, competing for attention, fighting over territory or food, and having different lifestyles. If a dog is super friendly and outgoing while a cat is more aloof and solitary, living together can naturally lead to conflicts. For example, when a dog always wants to get close to a cat, the cat might throw a tantrum. Plus, cats and dogs have different ways of communicating, so they might misunderstand each other during interactions. Also, dogs and cats often fight over attention, so owners need to make sure they’re treating them fairly.