Inter-Cat Aggression

Inter-cat aggression describes hostile or threatening behaviour between cats living in the same household. It can range from subtle posturing—a stare, a blocked doorway, a tense body—to overt physical conflict. The pattern may emerge suddenly after years of peaceful coexistence, or it may have been present, quietly, from the beginning. Owners often arrive at this page because they have seen hissing, swatting, chasing, or outright fighting. In some cases, one cat may avoid certain rooms, eat less, or seem persistently anxious, while the other appears calm. The signs can be episodic or persistent, and the triggers are not always obvious. This page explores the signals that suggest inter-cat tension, the social and physiological factors that can drive it, how the situation is typically assessed, and the range of approaches—environmental, behavioural, and medical—that may help reduce conflict and improve quality of life for both animals.