Research overview: cage design, double compartments and portals in shelter cat housing

Conventional small single-compartment shelter cages force cats to eat, sleep and eliminate in close quarters, raising stress and disease. This overview surveys research on improved housing, especially larger double-compartment cages connected by a portal that lets cats separate their litter box from feeding and resting areas. It examines evidence that such housing reduces stress, illness and the need to fully remove cats during cleaning, along with the welfare benefits of vertical space, hiding and adequate floor area. It discusses how housing design interacts with cleaning protocols, length of stay and adoption, and the shift in shelter-medicine guidelines toward larger, compartmentalised enclosures. The synthesis frames cage design as one of the most consequential and modifiable factors in shelter cat welfare.