Research overview: the chemistry of urine spray marking in cats

Urine spraying is a primary scent-marking behavior in cats, depositing a chemically rich signal on vertical surfaces. This overview surveys the composition of sprayed urine, which contains compounds such as felinine and its odorous sulfur-containing breakdown products that give cat marks their distinctive smell. These chemicals convey information about the marking cat's identity, sex, and possibly the recency of the mark as the volatiles change over time. The survey relates spray chemistry to detection by the olfactory and vomeronasal systems and to the social and territorial functions of marking. It discusses differences between males and females in the production of key compounds. Understanding the chemistry of urine spraying connects a common, sometimes problematic feline behavior to specific molecules and their messages. It frames spraying as deliberate chemical communication, in which the cat broadcasts detailed information through the composition of a carefully placed scent signal.