Cats were housed singly or in pairs in the English cat shelter pictured in these photographs. Acrylic plastic doors onto the communal corridor (A) prevented transmission of airborne fomites. The cats had access to a naturally ventilated outdoor pen through a cat flap (B). Excellent shelter design resulted in fewer infectious disease problems.
Courtesy of the Royal Society for the Prevention of Cruelty to Animals; photograph by Dr. Diane D. Addie.