Updated and reviewed for accuracy on April 7, 2020, by Dr. Katie Grzyb, DVM
When your cat starts urinating outside the litter box, the smell can be difficult to get rid of and nearly impossible to mask.
Whether your cat pees on the carpet, a piece of furniture, bed linens, or your clothes, it’s important to neutralize the odor to prevent your cat from becoming a repeat offender. Cats often return to a spot where they have previously urinated if the odor is not eliminated.
It’s also important to determine the cause of this behavior, which could be a sign of a health issue or stress.
Here is your ultimate guide to eliminating cat urine smells and determining why your cat is urinating outside the litter box to begin with.
Jump to Section:
- Products to Clean Up Cat Urine Messes
- How to Get Cat Urine Smell Out of Carpet
- How to Get Cat Urine Smell Out of Cushions
- How to Get Cat Urine Smell Out of a Mattress
- How to Get Cat Urine Smell Out of Linens and Clothing
Why Cat Pee Stinks
Cat urine is not all that different from other animals’ urine, but what gives cat urine such a bad smell?
Cat Urine Gets Worse With Time
Cat urine that’s outside the litter box is usually unnoticed until it becomes a problem.
After a while, the bacterium in the urine decomposes and gives off an ammonia-like odor that’s characteristic of stale, old urine.
In the second stage of the decomposition process, the urine emits mercaptans, which are compounds that give skunk spray its characteristic bad smell.
Older Animals Have Smellier Urine
Older cats have kidneys that have lost some of their efficiency, and as a consequence, they tend to have the worst-smelling urine.
Unaltered Males Have Hormones in Their Urine
Adding to the stench are the powerful hormones that cats eliminate when they pee. Unless male cats are neutered, their testosterone-spiked urine signals other males to stay away and lets females know they’re around.
Why Cats Urinate Outside of the Litter Box
There are a number of reasons why a cat may start peeing outside the litter box. While some owners may think that their cat does it as a way of getting even for something, cats lack the sophisticated cognitive abilities needed to concoct that type of revenge strategy.
“Despite popular belief, cats do not urinate outside the box to 'get back' at the owner for something,” said Dr. Laura George, DVM at Cats Exclusive Veterinary Center in Shoreline, Washington.
If your cat’s not using the litter box, it’s likely that he or she is trying to tell you something important.
Health Issues Can Cause Inappropriate Urination
The first thing you need to do is rule out a medical problem, says Dr. Bruce Kornreich, DVM, PhD, DACVIM, and associate director of the Cornell Feline Health Center.
Medical issues related to inappropriate urination can include urinary tract infections, kidney disease, diabetes, hyperthyroidism, and feline lower urinary tract disease. These can cause a cat to urinate outside the litter box, particularly if they associate the litter box with pain.
If you believe your cat is suffering from any of these conditions, or is exhibiting additional symptoms, bring them to your veterinarian immediately. Untreated conditions such as urinary tract infections can become serious.
Arthritis Can Make Litter Boxes Hard to Use
Another possible reason that an older cat may forego the litter box is arthritis. “As cats age, they can get arthritis, which makes it harder for them to get into the box,” Dr. Kornreich said. “Perhaps the sides are too tall, or the box is located in a place that requires the cat to do some kind of arduous physical activity to get to, such as up or down a flight of stairs.”
Behavioral Issues Could Be the Cause
Once you’ve ruled out any illness, determine if there’s a behavioral reason why your cat isn’t going in their usual spot.
“You need to be a detective and take the time to figure out why the cat’s behavior has changed,” says Sandra DeFeo, executive director of the Humane Society of New York.
According to DeFeo, not using the litter box is one of the most common reasons cats are relinquished to animal shelters. Fortunately, if you can pinpoint the reason behind your cat’s outside-the-litter-box behavior, you can often deter your cat from staining your carpet or bed linens.
“If there is not a medical problem and the problem truly is behavioral, early intervention is key,” Dr. George says. “Behavioral issues can sometimes be resolved by adding additional litter boxes around the home, scooping frequently to remove waste, or by moving a litter box from one space in the home to another.”
As a general rule, you should keep as many litter boxes as you have cats in the house, plus one. So, if you have two cats, you should have three litter boxes.
You can also try removing the cover of your cat’s litter box (if it has one) or changing the type of litter you use to encourage your cat to use his or her box.
Why Cats Spray
While some cats squat and urinate on bare floors, carpet, furniture, and other horizontal surfaces, others will spray urine on vertical surfaces around the home. “Unfixed males spray to mark their territory, and unfixed females spray to let tomcats know they are ready [to mate]” DeFeo says.
To avoid such behaviors, she suggests getting male cats neutered and female cats spayed at 6 months.
Although cats are often driven to spray by hormones, there are other reasons for it. Cats may spray out of stress, anxiety, or frustration with their circumstances, including such conditions as restrictive diets, insufficient playtime, or territorial disputes with other cats.
If your cat is spraying because of disputes with either other cats in the home or in the neighborhood, it’s important for you to try to resolve the issues.
Separate feuding cats in your household and reintroduce them slowly, using treats to reward and encourage peaceful behavior. To ease anxiety, try a plug-in diffuser that releases a synthetic cat pheromone developed to reassure your cat.
If your cat is spraying out of stress or anxiety, discuss these issues with your veterinarian and work with them to develop a solution to minimize your cat’s stress.
Clean Up Cat Urine Stains Before They Smell Worse
As bad as cat pee initially smells, the longer that urine sits, the worse the stench becomes. “The smell gets more concentrated over time,” Dr. Kornreich says.
Additionally, once a urine stain dries, you may no longer see it, but you can still smell it, and so can your cat, leading him or her to mark that area again.
“When it comes to cleaning up cat urine, many cat owners make the same mistake—not cleaning it up quickly enough,” says Meg Roberts, president of Molly Maid, a residential cleaning company.
Several products can help neutralize cat pee odor, including vinegar or baking soda and enzymatic cleaners. Here are some options to help you get rid of the cat pee smell.
Baking Soda and Vinegar
Vinegar, while a bit smelly itself, works to remove the lasting odor of sprayed cat urine because vinegar is an acid that neutralizes the alkaline salts that form in dried urine stains.
A solution of one part water and one part vinegar can be used to clean walls and floors. Proponents say that the vinegar smell subsides after a few days, taking the urine smell with it.
For odor elimination in carpets, couch cushions, mattresses, and linens, you can try an enzyme-based cleaner. The enzymes in these products actually break down the acid in cat urine, helping to get rid of the smell at the same time. The natural enzymes and helpful bacteria help get rid of the bad bacteria that’s causing the unpleasant odors.
When cleaning any surface, it’s important to get to the point where not only can you not smell the urine, but your cat can’t smell it, either. “When a cat can smell a previous urine spot (from themselves or another cat), that area is likely to be used again,” Dr. George says.
Avoid Products That Contain Ammonia
Most importantly, avoid any cleaning products that contain ammonia. “Ammonia is one component of cat urine, and if cats smell that, they’re more likely to go there,” Dr. Kornreich says.
In addition, ammonia and other chemical cleaners can often set the stain—the opposite of what you’re trying to do.
Here’s what you should do to help eliminate the smell of cat pee from a surface.
1. Blot the Spot to Absorb the Urine
Find the stain as soon as possible and blot up as much of the urine as you can with a clean cloth.
2. Rinse and Vacuum the Area
Next, rinse the area with clean water and remove the liquid with a wet/dry vacuum. “You don’t want to use a steam cleaner, as the heat can set the stain,” Roberts said.
3. Soak the Spot in Enzyme Cleaner
While enzyme cleaners come in a spray bottle, spraying a light coat over the stain won’t do much. Instead, remove the sprayer and douse the spot liberally.
4. Let It Sit Before Blotting With a Clean Cloth
Let the cleaner sit for 10-15 minutes and blot up as much of it as possible with a clean cloth.
5. Prevent Your Cat From Returning to the Spot
To keep your cat from returning to the spot during the cleaning process, place a piece of aluminum foil or an aluminum baking sheet over the area, or cover it with an upside-down laundry basket.
6. Reapply the Cleaner if Necessary
You may need to reapply the cleaner and let it dry again for older or particularly smelly stains.
Removing Cat Urine Smells From the Subflooring
Urine can often soak through the carpet and into the subflooring, leaving a stain and a stench that can’t be lifted with carpet cleaner and elbow grease.
If you have pet odor that will not go away despite your best carpet-cleaning efforts, neutralize the scent by using an oil-based, stain-blocking primer on the subfloor beneath the carpeting. Replace the padding as well as that area of carpet.
Here a few easy steps you can take to remove the cat pee smell from a cushion.
1. Soak the Area in Water
Soak the affected area of the cushion with water. Blot up as much of the cat urine as possible with a towel.
2. Soak the Area With an Enzyme Cleaner
Then soak the cushion by very slowly, pouring the enzyme cleaner on and around the affected area.
3. Let It Sit Before Blotting With Towels
Let it sit for 15 minutes, then squish out as much of the excess enzyme cleaner as possible before blotting with towels.
4. Let the Cushion Dry
If possible, leave the cushion outside as long as possible while it dries. Since cushions take days to dry, lay aluminum foil down before putting the cushion back, then put a second layer of foil over the top of the cushion to discourage your cat from peeing on the cushion again.
Mattresses require almost the same process as cushions.
1. Soak the Area in Water
Soak the affected area of the mattress with water. Blot up as much of the cat urine as possible with a towel.
2. Soak the Area With Enzyme Cleaner
Then soak the mattress by very slowly pouring the enzyme cleaner on and around the affected area.
3. Let It Sit Before Blotting With Towels
Let the enzymatic cleaner sit for 15 minutes and then blot it up. Place several layers of clean towels over the mattress and then make the bed.
4. Let the Mattress Dry
Swap out the towels each day until the mattress completely dries. To discourage peeing on the spot while the mattress dries, cover the bed with a large plastic sheet or tarp when you’re not using it. You can also get a waterproof mattress cover to protect it from future incidents.
5. Reapply If Needed
Mattresses may require several applications to completely remove the cat urine.
One important rule with linens and clothing is: NEVER use bleach—when mixed with ammonia and cat urine, it can cause harmful gases.
1. Rinse the Spot With Cool Water
If your bed linens and clothing are machine washable, first rinse the spot in a sink with cool water.
2. Wash With Detergent and Baking Soda or Cider Vinegar
Add the items to the washing machine with detergent plus a cup of baking soda OR a quarter cup of cider vinegar.
3. Add Enzyme Cleaner If the Smell Persists
If you can still smell the urine after the cycle is complete, add enzyme cleaner to the load (following instructions on the package) and run the cycle again.
4. Air-Dry After Washing
Always air-dry linens, as the heat of the dryer may lock in the smell before it’s completely gone.
You may need to rewash one or more times until the scent is completely gone.
Keep Your Cat From Urinating in That Spot in the Future
Once you’ve cleaned a particular area, prevent a recurrence by changing the significance of that area to your cat. In other words, since cats prefer to eat and eliminate in separate areas, place food bowls and treats in previously soiled areas, or play with your cat in that space and leave toys there.
By Michelle Shapiro
Featured Image: iStock.com/Maryviolet