Why Do Cats Urine Mark?
Animal species who live in social groups in which the members depend on each other for survival have sophisticated interpersonal communication. Particularly animals who can cause significant harm to each other—like dogs—have developed a social mechanism for preventing conflict through interpersonal ranking. They are prepared to assume either a leadership or deference position, and they can read another animal’s body language to interpret his intentions and react accordingly. But cats have a somewhat unique social structure in that they do not hunt, eat or sleep in groups like dogs.
Given the opportunity, cats go off on their own when they mature and claim certain areas or territories for themselves. They might share a territory with other cats, but it’s a time-share approach—they avoid each other whenever possible. They haven’t developed a social system or a communication system like dogs. Socially, cats who greet often handle things like two neighbors in an argument—although one might back down if he thinks he might get injured—neither individual will ever perceive himself as having lower status than the other. Cats have no system for working out face-to-face disputes, so face-to-face disputes can be dangerous for them. To avoid disputes, cats communicate indirectly—they leave messages.
Cats have numerous ways to leave messages for each other, and one way is through urine marking. By urine marking, a cat tells other cats of his presence and makes a statement about such things as what piece of property is his, how long ago he was in the area and, over time, when other cats can expect him to return. Cats can even advertise when they are looking for a mate. All this information is available to other cats in the urine. This way, cats rarely have to meet up with each other.
Cats who live in houses might not have to hunt for their food or find a mate, but they still look at their world in the same way as cats who must survive on their own. They can only use the social and communication skills that nature gave them. If their world is predictable, there are no conflicts, they are spayed or neutered and they don’t need a mate, cats have little reason to mark and probably will not. But, if they want a mate or they are distressed about something, they’ll deal with their distress like any cat: they’ll mark their territory. To a cat, marking helps keep unwanted individuals away—whoever and whatever those individuals may be—and it creates an atmosphere of familiarity that makes them feel more secure.
Urine Marking in Cats ASPCA