"Stress" can be documented in cats via behavioral assessments or physiologic testing (e.g., measurement of cortisol concentrations). The former type of assessment is noninvasive but subjective. Physiologic testing is objective but hampered by the fact that restraint alone can cause stress. In this study, 120 randomly selected cats from 4 shelters that used various methods to house their cats were scored for stress on 2 different days. On the first day, cats were scored using a behavioral scale (cat stress score) by observing them in the morning, at midday, and in the evening. The next day, urine samples were collected for urine cortisol-to-creatinine ratios (UCCRs). The behavioral assessment found that cat stress scores were highest in the morning; these scores did not correlate with the length of time the cat had been in the shelter. The UCCRs did not correlate with the cat stress scores but did correlate with signs of systemic illnesses. Stress scores were highest when cats were exposed to dogs and lowest when the cats were housed in "cat friendly" environments (e.g., soundproofed cages, enlarged cages, cat perches). Unexpectedly, 25% of cats had evidence of hematuria on urine dipstick.

COMMENTARY: The lack of correlation between the cat stress score and the UCCR clearly demonstrates that stress in cats is easily underestimated by even the most observant caretakers. This is important because in this study, as in others, signs of systemic illness and stress were strongly correlated. That 25% of the cats had hematuria shows how easily illness can be overlooked in a confined cat. More studies of this type need to be conducted or consulted when animal shelters as well as veterinary clinics are being constructed or remodeled.

Assessment of stress levels among cats in four animal shelters. McCobb EC, Patronek GJ, Marder AM, et al. JAVMA 226:548-555, 2005.