Urine marking can bring anger to a pet guardian faster than almost any other cat behavior. While you are trying to stop this behavior, keep in mind your cat is doing something that comes very natural to him or her. Your cat is not marking out of spite, anger, or to cause you stress. They spray either to attract the opposite sex (in unneutered/unfixed cats) or to ease their stress when they are feeling anxious or insecure. If you choose to not spay your cat, then there is not much you can do to stop them from marking; it is too much a part of their nature. If your cat is spayed, then you need to keep in mind they are attempting to calm themselves. The smell of their scent makes them feel in control and safe.
Rule out any physical problems. Taking a quick trip to your veterinarian can rule out any health issues, especially urinary tract infections. Discuss your observations with the vet. Most likely they will run a few tests (urine and blood) to eliminate any health concerns.
Review the basics. Rule out any of the simple solutions first. Did you recently change the type of litter your cat is used to? Did you move the litter box to a new location? Did something dramatic occur in the area where your litter box is located (this could be a loud sound, a dog scaring the cat, etc.)? Did you recently clean the litter box and use a cleanser your cat doesn't like? Does your litter box need to be cleaned? Each of these are simple fixes: Go back to your old litter; try a different location as your cat is telling you he doesn't like the new one; unless you are sure there is nothing in the area that could have scared your cat, try a new location to see if the spraying stops; do not use strong cleaners (especially ammonia based ones) as cat's do not like these strong smells (basic soap and water or bleach work best, rinse well); replace the litter.
Track the spraying history and locations. Once you start noticing your cat is spraying, it might be helpful to begin a "Cat Diary" in which you track your cat's spraying. Basically, you want to record where he is spraying, when you found it, the condition of the spray (dry, wet, you witnessed the actual act), and if anything critical occurred beforehand (i.e., a cat fight, loud noise from outside, you brought in some new items, etc.). If you're lucky, reviewing the history may show a very specific pattern where all the markings are occurring at certain times of day, or near windows and doors, or on your personal items, or only on items coming in from the outside. This will significantly help in figuring out what the "trigger" is and how you might be able to treat it (Step 4).
Figure out the trigger. If you can figure out what triggered the marking to start, you can potentially fix the issue and stop the marking. Try to determine when the spraying began and what changes occurred during this time interval. Did a new cat or dog move into the neighborhood? Did you get a new roommate or lose a roommate? Is there new stresses in the household (changes in your schedule, are you going out more, did you lose or gain a roommate or other house guest, is someone fighting or depressed, etc.)? Cats are extremely sensitive to their guardian's moods and will notice if you are not feeling well, are depressed, or are angry more than normal. Is there new construction or new sounds occurring that were not there before? Are you bringing in outdoor items that you didn't before (bikes, shoes, work supplies)?
Cats that are kept completely indoors can be more sensitive to changes in the smell of their household. New "outdoor" smells can cause them to feel insecure and trigger them to spray to calm themselves down. Unfortunately, sometimes the trigger is out of your control. If it is due to the presence of an outdoor cat or construction, you cannot eliminate these items. The following steps provide alternative methods to help limit and prevent the spraying.
Remember to stay calm and try to provide more comfort and security to your cat. Yelling at your cat or punishing him will just intensify his stress and cause more marking. Keeping calm and providing additional comfort will help build his confidence and potentially lead to a feeling of more security. For insecure cats, sometimes providing more attention throughout the day can ease their stress.
When you enter a room with your cat in it, try saying his name in a tone he finds comforting. Massage therapy also is a good method to interact with your cat and relieve stress. Massage his back in small circular motions; this method of touch can provide a calming effect. Play with the cat more to help release stress.
The use of pheromone sprays creates a "happy" feeling in most cats, which eases their tension and stops the need for marking. One of the most popular pheromone sprays is Feliway, which you can apply directly on surfaces or use in a diffuser form. The diffuser form naturally spreads pheromones throughout your house so you don't have to know exactly where your cat is marking all the time; however, these can be more expensive as you need to purchase enough to cover your entire house (the boxes provide the area each diffuser can cover) and replace them monthly. The use of flower essence also provides a calming effect. Try adding a couple of drops of flower essence (Bach Rescue Remedy, chestnut bud, vervain, or vine are typical essences used for spraying) to your cat's water each day for a few weeks.
Cover the areas with aluminum foil or wax paper. If your cat is marking in very specific locations, try covering these locations with aluminum foil or wax paper. The sound will startle them and potentially scare them from marking that location anymore. If you place foil/paper beneath the spray point as well, it should protect it from soaking in. Be forewarned though, your cat might start marking new locations, so it is still beneficial to figure out and eliminate the trigger if possible.
Place food and water dishes wherever your cat is marking. If you can deal with having small dishes throughout your house for a few weeks, this is a very good way to prevent your cat from spraying in certain areas. Cats will not typical spray near their food and water. Try placing small dishes throughout the areas he is marking. Keep adding new bowls wherever his marking pattern goes. Even gluing some food to a paper plate should work.
Get rid of the smell. Use a cleanser with natural enzymes (Nature's Miracle is a great product) to treat all of the areas your cat has marked. Even if you figure out and eliminate the trigger, if you still have lingering urine smells, your cat might be tempted to mark. Don't think just because you cannot smell it, your cat cannot as well. The best way to ensure you are treating every spot is to treat as you find them (thoroughly, thoroughly, thoroughly soak the areas, repeat as needed until you definitely feel the areas are clean), go through your house in the dark with a true ultraviolet light (Wood's Lamp) to find markings you might have missed (these will florescence under the ultraviolet light), and crawl around at your cat's level to smell for yourself. It is amazing what you will smell at a cat's height versus your own.
Claim your walls and furniture. I am not sure this works for females as well as males, but for my male kitty, this worked amazingly well. Clean up his marking when he is watching using a spray bottle (Nature's Miracle). Clearly state this is "My wall!" Look at him when you say this. For my kitten, this sank in very well. I claimed all the wall space while he watched me and even sprayed the furniture. As cats usually find security with their people, I believe it does not stress your cat by you claiming your walls and furniture, but rather gives them a since of comfort because they are yours and not the other cats. I believe this works better in multi-cat households where there might be some inter-territorial issues.
Isolate your cat for awhile. Some cats find smaller living spaces more secure and calming. Try keeping him in a room with as little furniture or areas to mark as possible. Don't forget to provide the basic necessities (food, water, bed, litter box, and some toys; keep the bed and food/water as far from the litter box as possible) and to still spend time with him throughout the day. Observe your cat to make sure the isolation is having a calming effect and not causing more stress. After a few days or a week, try letting your cat out to see how he reacts. If you catch him spraying, bring him back to the room for another few days.
Urine marking can create a lot of stresses in a household. Try to keep your perspective throughout this time. Your cat is not trying to ruin your stuff or cause you stress, he is just trying to feel secure and create a feeling of safety. Try to replace any anger with compassion; your cat is claiming you and your home as his (which I know is not all that comforting at the time of finding a marking, but really is a nice gesture if you think about it). Taking the time to help your cat is not too much to ask, especially when you consider all of the comfort and joy we get from them.