Carlstead, K., Brown, J. L., Strawn, W. 1993. Behavioral and physiological correlates of stress in laboratory cats. Applied Animal Behaviour Science 38, 143-158.

These results indicate that qualitatively poor caretaking is a potent psychological stressor for confined [single-caged] cats that may eventually compromise reproduction through behavioral or physiological mechanism. To promote well-being, caged cats should be provided with appropriate places for concealment.