The objective of this study was to survey cat owners regarding the frequency and duration of their daily interactions with their indoor cats, the provision of toys and activities by the cat owners, and the prevalence of 6 selected behavior problems (aggression to owner, aggression to visitors, periuria, inappropriate defecation, inter-household cat aggression, and intercat aggression to outdoor cats).
http://dx.doi.org/10.1016/j.jveb.2014.06.005