Assessment of stress levels among cats in four animal shelters.

To measure stress levels among cats in traditional and enriched shelter environments via behavioral assessment and urine cortisol-to-creatinine ratios. Cross-sectional observational study. 120 cats in 4 Boston-area animal shelters. Cats were randomly selected and observed during 3 periods (morning, midday, and afternoon) of 1 day and scored by use of a behavioral assessment scale. The next day, urine samples were collected for analysis of the urine cortisol-to-creatinine ratio. Information about each cat's background before entering the shelter was collected. Stress scores were highest in the morning. The relationships between the amount of time cats spent in the shelter and the cat stress score or urine cortisol-to-creatinine ratio were not strong. There was no correlation between the cat stress score and urine cortisol-to-creatinine ratio. Urine cortisol-to-creatinine ratios did correlate with signs of systemic disease and were significantly lower in cats in the more environmentally enriched shelters, compared with cats in the traditional shelters. Urine cortisol-to-creatinine ratio was highest among cats with high exposure to dogs. Of the cats in the study, 25% had subclinical hematuria detectable on a urine dipstick. In this study, the cat stress score was not a useful instrument for measuring stress because it failed to identify cats with feigned sleep and high stress levels. Urine cortisol-to-creatinine ratios can be monitored to noninvasively assess stress levels in confined cats. Environmental enrichment strategies may help improve the welfare of cats in animal shelters.