Feline Inappropriate Elimination: Breaking the Cycle of Smell

Cats will return to and reuse areas where they have previously urinated. Because of this, cleaning up the areas and items where your cat has urinated or defecated is a crucial step to breaking the cycle, as well as preventing damage to the item. Because it is much easier to eliminate odors in recently-soiled areas, clean them as soon as possible. If you’re not sure of the extent of the soiled spot, a black light will easily illuminate urine and fecal matter on items. The black light will also help identify areas that you may not know were being soiled - check the walls and floor for several feet in every direction from the spot being soiled. It may help to use chalk to outline the urine spots for easy cleaning. Check the underside of chair and couch cushions and pillows to see if the urine has penetrated all the way through - if so, then your enzymatic cleaner will have to penetrate fully, too. Black lights work best in a darkened room. If you have the plug-in variety of black light, use an extension cord so that you have freedom to move around the room without having to constantly move the plug from outlet to outlet. Otherwise, there are a variety of hand-held, flashlight-type options.

Outlined spots for easy treating.

The rule of thumb when treating carpet or other absorbent surfaces for urine spots is to use twice as much cleaner as the size of the spot that you are treating. Urine will disperse down through the carpet and into the padding beneath, and may even absorb into the floorboards below that.

A cat's sense of smell is 200 times stronger than ours; therefore odors must be neutralized, not just deodorized. It is also best to avoid cleaning products containing ammonia or vinegar—they smell like urine and can be irritating. In order to neutralize the odor, use an enzyme-based cleaner such as Urine-Away, Nature’s Miracle, Simple Solution or Nok-Out. These cleaners break down the odor molecules rather than just covering up the smell. Sometimes, if the problem has been going on for a long period of time, it may be necessary to replace urine-saturated flooring.

•   Sheets of plastic, newspaper, sandpaper, double-sided tape, or a carpet runner with the nubs facing up may all discourage your cat from entering a soil-prone area.
•  Try changing the significance of a soiled area. Cats prefer to eat and eliminate in separate areas, so try placing food bowls and treats in previously soiled areas. Playing with your cat in that space and leaving toys there may also be helpful. 
• Spray the area with a pheromone spray or use a diffuser to provide pheromone all day long - the Feliway pheromone is a "happy" smell to a cat and signifies that the area is not for elimination. It also has a calming effect.
•  Try denying your cat access to a given area by closing doors, or by covering the area with furniture or plants. Baby gates will not keep most cats out of a room.
• Catch him in the act. A bell on a breakaway collar tells you his whereabouts. If you can catch him within the first seconds of his elimination routine, startle him with a water gun or shake a jar of pennies, so that he associates being startled with those actions. It is important that you startle rather than scare him; fear will only worsen the problem. Moreover, if you catch him after he's eliminated, your window of opportunity is gone—you must catch him just as he's about to eliminate. 

Never hit, kick, or scream at a cat. Not only does this create more anxiety, which may contribute to house soiling behavior, but also such tactics provide no link between the "crime" and the punishment. Some owners resort to rubbing their cat's face in their excrement to "teach the cat a lesson." This is ineffective, first because cats do not view their urine and feces as distasteful, and second, because even moments later, cats cannot make the connection between the mess on the bed and this kind of punishment.

More information about inappropriate elimination:
Lovin' the Litterbox: Husbandry Reasons Why Your Cat May Not Use the Litterbox
Kidneys and Crystals and Stones, Oh, My! Medical Reasons Why Your Cat May Not Use the Litterbox
Acting Out All Over the House: Behavioral Reasons Why Your Cat May Not Use the Litterbox