Andrukonis, A., Protopopova, A., Xiang, Y. et al. 2021. Behavioral correlates of urinary output in shelter cats. Applied Animal Behaviour Science 241, 105397.

United States’ animal shelters take in 3.2 million cats per year. Caged cats likely experience stressful situations during their stay at an animal shelter. However, a feasible and efficient way to determine which cats will be at the highest risk for severe stress, and subsequent health and behavior deterioration, is needed. We aimed to determine whether urinary output was suppressed immediately following a presumably stressful move from one location to another in the shelter and whether this suppression correlated with behavior in cats admitted to an animal shelter. Prior to addressing this aim, we first evaluated the use of litter clump weight to determine urine output. Then we aimed to determine whether behavior, using an established in-cage assessment, predicted urinary suppression in cats. Litter clump weight was significantly predicted by quantities of water added to the litter (50 mL, 100 mL, and 150 mL), suggesting that litter clump weight can be used as a marker of crude urine output. Next, newly-admitted shelter cats (n = 29) were subjected to an in-cage behavioral assessment. For the following week, urine clumps were weighed daily. Clump weight increased significantly (F = 17.926, p < 0.0001) after Day 1, suggesting an initial suppression perhaps due to acute stress (i.e. moving to the adoption floor). A principle component analysis (PCA) of in-kennel behavior followed by linear regression was conducted to predict Day 1 urine suppression and found that the sixth and eighth components (PC 6 and PC 8) showed modest prediction of urine suppression. A support vector machine (SVM) was also used to classify cats as having “less” vs. “more” urine suppression at three different cutoffs (10 %, 25 %, 50 % suppression on Day 1). The SVM had an average training accuracy of 86.3 %, 81.8 %, 84.1 % at 10 %, 25 %, and 50 % suppression respectively. These data suggest that urinary suppression (measured through litter clump weights) may be a practical way to track wellbeing in shelter cats and that a SVM may have modest ability to classify cats at risk of suppressed urine output based on behavioral responses to a brief test.