Feline marking occurs when cats mark their territory either by spraying urine, cheek rubbing or scratching.  Cats mark the areas where they live or visit in many ways.  They often mark territory with urine by spraying small amounts of urine onto vertical surfaces and, less commonly, by leaving small amounts of urine on horizontal surfaces.  Cats also mark with scent glands on their cheeks, face, feet, and tail by cheek rubbing or scratching.

Leaving an odor communicates that the animal was in a location long after it has gone.  Cats mark their territory to signal "ownership" and to advertise sexual availability.  Many cats also mark their territory when they feel threatened or stressed.  Because marking delineates territory, urine is often found in prominent indoor locations, at entrance and exit points to the outdoors, and around the periphery of the home.  Outdoors, cats often mark in similar places, as well as locations where other cats have marked.

Both male and female cats mark with urine.  Urine marking is most common in intact male cats, but approximately 10% of neutered males and 5% of spayed females continue to spray. While cats in multiple-cat households are more often involved in spraying behaviors, cats that are housed singly may spray as well.

Some cats mark their territory with small amounts of urine (and rarely feces) in various locations.  Small amounts of urine deposited outside the litterbox are more commonly due to litter box avoidance, which could have many causes, from simply a litter box that isn't cleaned often enough to a serious disease of the lower urinary tract.

As with all behavior problems, the history is very important in helping to determine treatment options.  Treatment is aimed at decreasing the motivation for spraying.  If the cat is not already neutered, and is not a potential breeder, doing so is recommended.  Spraying can be reduced in some cases by ensuring that the litter box(es) is cleaned daily or maybe even more frequently depending on the number of cats in the home.

If marking appears to be stimulated by cats outside the home, then the best options are to find a way to deter the outdoor cats from coming onto the property or to prevent the indoor cat from seeing, smelling, or hearing the outdoor cats.

If the problem is related to the social interactions of the cats inside the home, it may be necessary to determine which cats do not get along.  Keeping these cats in separate parts of the home with their own litter boxes and sleeping areas may help.  Gradually reintroducing the cats may be possible when they are properly supervised.

Because the cat sprays to mark an area with urine odor, it is not surprising that as the odor is cleaned up, the cat wants to "refresh" the area with more urine.  This means that cleaning alone generally does little to reduce spraying.  Cats that mark in one or two particular areas may stop if the function of the area is changed.  When practical, a good compromise for some cats may be to allow them one or two areas for marking.