Influence of indoor-cat group size and dominance rank on urinary cortisol levels

Abstract

AbstractDomestic cats (Felis silvestris catus) are often housed indoors both singly and in groups. However, there is a lack of studies dealing with cat-cat relationships, group composition and effects of environmental parameters on the well-being of privately-owned cats. One way to index the effects of stressful situations is to measure glucocorticoid levels, as glucocorticoids are released from the adrenal cortex in response to stress-induced activation of the hypothalamic-pituitary-adrenal axis. Therefore, we investigated the influence of single and group housing on basal urinary cortisol levels of indoor-only domestic cats in private households, taking into account dominance status and environmental parameters. Urine samples were collected non-invasively by owners from six single-housed cats and six alpha-omega animal pairs of multi-cat households. Dominance status in group-housed cats was determined by competition test series. Additionally, we compared cortisol levels of privately-owned cats with those of shelter cats. Results showed that basal urinary cortisol levels of cats in private households are neither influenced by housing style (single cat vs multi cat) nor by individuals' dominance status. Correlations indicated a positive influence of human density, number of persons per household, and number of m2available to cats on basal urinary cortisol levels, whereas cat-related parameters such as number of cats per household, number of m2per cat, and number of persons per cat, did not have any significant influence on basal urinary cortisol levels. A comparison of basal urinary cortisol levels of privately-owned and shelter cats revealed no influence of location (private household, shelter) and group type (single, group [dominant or subordinate]) on basal urinary cortisol levels. This study is the first to investigate basal urinary cortisol levels of domestic cats in private households and an animal shelter considering housing style, dominance status, and environmental parameters.