Thinking inside the box: do hiding boxes reduce the fear and stress of hospitalised cats?

PICO question: In hospitalised domestic cats, does the use of hiding boxes compared to no intervention reduce fear and stress? Clinical bottom line: Category of research: Treatment. Number and type of study designs reviewed: Five studies were critically reviewed. All five studies were defined by the researchers as randomised control trials. Strength of evidence: Moderate. Outcomes reported: Four of the five studies showed moderate evidence that hiding boxes reduce fear and stress in cats, with reduced cat stress scores (CSS) in cats given a hiding box compared to control groups. The hiding box was found more useful in aggressive cats as CSS reduced faster in these groups. Among the three studies that recorded objective physiological stress measures (e.g., temperature, salivary cortisol), two studies showed no statistically significant stress reductions between the hiding box and control groups. Only one study of these three found lower heart rates in hiding box cats, but this may have been influenced by confounding factors. Conclusion: There is moderate evidence suggesting that the use of hiding boxes in hospitalised cats is associated with reduced stress. The strength of the evidence is considered moderate due to varying limitations (e.g., small sample sizes) in the reviewed studies. Despite these limitations, incorporating a plastic or single-use disposable cardboard hiding box into existing feline-friendly cage environments is recommended for consideration. However, the use of a hiding box should be determined on a case-by-case basis as it may not be suitable for all patients (e.g. critical care patients requiring constant visualisation). High-standard infection control protocols should be applied to ensure the hiding box does not act as a fomite for possible infection transmission.