Uncontrolled outdoor access is associated with a number of welfare concerns for companion cats, including increased risks of disease and parasites, injury or death due to traffic, predation or ingestion of toxic substances, and getting permanently separated from their owner. In addition, cats pose a threat to local wildlife due to predatory behaviors, and can sometimes be a nuisance to human neighbors. Despite these concerns, recent estimates suggest that many owners are still providing their cats with uncontrolled outdoor access, likely because it also offers welfare benefits by allowing cats to perform natural behaviors, such as hunting, exploring, and climbing. While some have suggested that outdoor access is necessary to meet cats’ behavioral needs and to prevent related behavioral problems, others have recommended various environmental enrichment strategies that can be developed to meet these needs within an indoor environment or through supervised and controlled outdoor access. This review examines the welfare issues and benefits associated with outdoor access for cats, as well as what is currently known about peoples’ practices, knowledge, and attitudes about the provision of outdoor access for cats.

The chronic variable stress (CVS) paradigm is frequently used to model the changes in hypothalamic pituitary adrenal (HPA) axis function characteristic of many stress-related diseases. However, male C57BL/6 mice are typically resistant to CVS’s effects, making it difficult to determine how chronic stress exposure may alter acute HPA function and regulation in these mice. As social support in rodents can profoundly influence physiological and behavioral processes, including the HPA axis, we sought to characterize the effects of CVS exposure on basal and acute stress-induced HPA axis function in pair- and single- housed adult male mice. Despite all subjects exhibiting decreased body weight gain after six weeks of CVS, the corticosterone response to a novel, acute restraint stressor was enhanced by CVS exclusively in single-housed males. CVS also significantly increased arginine vasopressin (AVP) mRNA in the hypothalamic paraventricular nucleus (PVN) in single-housed males only. Moreover, in single-, but not pair-housed mice, CVS attenuated decreases in circulating OT found following acute restraint. Only the effect of CVS to elevate PVN corticotropin releasing hormone (CRH) mRNA levels after an acute stressor was restricted to pair-housed mice. Collectively, our findings suggest that social isolation reveals effects of CVS on the HPA axis in male C57BL/6 mice.