Cat Aggression Between Household Cats

Inter-cat aggression in multi-cat households is extremely common and causes chronic stress for subordinate cats - understanding causes and management enables welfare improvement.

Key Facts

Cats are not naturally social in the same way as dogs - they are facultatively social rather than obligate group animals
Multi-cat households create resource competition that drives aggression when resources are insufficient
The rule of thumb for litter boxes is one per cat plus one extra - inadequate litter provision drives tension
Spraying, hissing, stalking and blocking access to resources indicate territorial inter-cat conflict
Vertical space and multiple exit routes reduce conflict by enabling subordinate cats to avoid dominant ones
Pheromone diffusers including Feliway MultiCat can reduce inter-cat tension in some situations
Cats that were not properly socialised together or were introduced too rapidly are at higher aggression risk

Welfare Considerations

Inter-cat aggression welfare causes chronic stress for subordinate cats that cannot escape an incompatible housemate. Unlike dogs, cats cannot always be successfully socialized to coexist peacefully - some combinations are genuinely incompatible. The welfare of a chronically stressed subordinate cat being stalked and blocked from resources is significantly compromised. Management addresses both physical environment (resources, escape routes, vertical space) and the human factor of realistic assessment of whether cats are genuinely compatible. Some cats have welfare needs best met as sole pets - the misconception that cats should always have a companion can cause welfare harm when cats are forced to coexist.

What You Can Do

Provide one litter box per cat plus one extra in multiple locations throughout the home
Create abundant vertical space with cat trees and shelves so subordinate cats can retreat upward
Ensure multiple feeding stations, water bowls and resting areas in different parts of the home
Consult a clinical animal behaviourist if aggression is severe or not responding to environmental management
Be willing to consider that some cats may have welfare needs better met as sole pets