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Can Dog Urine Cause Mold On Carpets?

Can Dog Urine Cause Mold On Carpets?

Dogs are prone to urinating on carpets especially when they are either young or older, but is this a huge problem, and can dog urine cause mold on carpets?

Unfortunately, dog urine can cause mold on carpets, especially if it soaks into the padding and subfloor and is left for extended periods of time.

Let’s take a look at the range of problems that dog urine can lead to with carpets and the key facts you need to know.

Problems Dog Urine Can Cause With Carpet

The problems that dog urine can cause with carpeting go beyond the risk of mold forming. These wet spots will also emit an odor. If the moisture reaches the subfloor before it is cleaned up, it can cause damage to the subfloor in addition to the carpet damage it already caused.


The smell that pet urine leaves behind is more than just unpleasant. It can be dangerous to people with weakened immune systems, or those with COPD Chronic Obstructive Pulmonary Disease, emphysema, or asthma. The odor can also invoke or irritate allergies.

Dog urine tends to have a very high concentration of ammonia which causes it to emit an offensive odor.

If it is not cleaned up properly and immediately, even after the liquid evaporates, it will leave behind a concentration of ammonia that will create smelly fumes.

The smell may entice the dog to become a repeat offender. While the smell may be quite putrid to humans, dogs have a heightened sense of smell.

If they detect urine, they will be more likely to be attracted to that spot to urinate again in the same location.


Any moisture that sits unattended has the potential to develop mold. The bacteria and fungus found in mold, like penicillium or aspergillus, can cause respiratory issues and will only become more of an issue the longer it is left to grow on or under the uncleaned carpet.

Subfloor damage

If the urine is not cleaned up quickly, or if the wetness happens time and time again, it will begin to soak through the carpet down into the padding underneath. This damage includes mold growing under the carpet which can cause a host of health problems.

Once the urine or any wetness sinks into the subfloor, it can sit there long enough to cause wood rot. If it gets to this point, you will need to remove the carpeting and replace the damaged sections of the subfloor. It may have become so bad that you have no alternative but to call in a professional for help.

Carpet Damage

If dog urine is not cleaned up properly and in a timely fashion, it will soak into the carpeting and leave stains behind. These stains can be very challenging to remove and may even cause permanent carpet damage.

How To Clean Dog Urine In Carpet

It’s important to act quickly to clean up any urine stains in carpeting before they become a problem. Here is a step-by-step guide to cleaning dog urine from carpet:

  • Get rid of the urine smell by soaking up as much wetness as you can immediately
  • Use a paper towel to dab or gently blot the puddle
  • Don’t smear or wipe the liquid around, since this will spread the stain
  • Dispose of the wet paper towel in an outside garbage container

You can also use enzymatic cleaners or baking soda.

  • Enzymatic cleaners will break down the molecules of the urine and get rid of the odor.
  • Baking soda is a natural alternative for deodorizing. Sprinkle a small amount of baking soda on the wet spot, and use a soft-bristled brush to gently work the powder into the carpet. Let it sit overnight, and then vacuum it up.

Be sure to completely dry out the wet carpet after you clean up the urine spot. If necessary, place a fan, or open windows to allow fresh air to circulate.

Cleaning Old Urine Stains In Carpet

Use a black light to locate old urine stains. Once you locate the old stains:

  • Act quickly
  • Use an enzymatic cleaner, baking soda, or another odor-eliminating treatment.
  • Blot the urine stain with a clean cloth or paper towel that will quickly absorb the wetness
  • If you have a shop-vac or wet/dry vac, use it to extract any remaining moisture. Be careful when using a vacuum to clean up mold since vacuuming can cause the spores to go airborne to be breathed in. Instead, wet/dry vacuum up old stains that are deeply embedded. Always use cold water and not hot or warm, since the warmer the water is, the urine will bond to the fabric making it even more challenging to remove it.

Using Dish Detergent to Clean Old Stains

Use one-quarter teaspoon of liquid dishwashing detergent and mix it with one cup of warm water. Do not use laundry detergent or soap meant for a dishwasher appliance, since these may contain bleach or lanolin. Alternatively, use white vinegar and water or half a cup of three percent hydrogen peroxide with a teaspoon of dishwashing detergent.

  • Use a spray bottle to spray the solution onto the stain directly
  • Extract the solution from the carpet using a shop-vac, or use a cotton cloth or a paper towel to blot it
  • Rinse the area with warm water being careful not to oversaturate the carpet
  • Rinse and repeat until the stain is gone
  • Be sure to thoroughly dry the area leaving no moisture to mold
  • Once the area is completely dry, vacuum the carpet

When to Seek Professional Carpet Cleaning or Repair

Call in a professional carpet cleaning service if the cleaning becomes overwhelming or if you have just moved into a new home that came complete with dog urine stains and mold. A professional will steam clean to disinfect. It’s a good idea to annually have your carpet professionally cleaned whether you have mold or not.

If all else fails, and the urine stains have become so embedded into the carpet that you cannot get clean, it may be time to call in a professional to completely remove the carpeting or sections of the flooring beyond spot cleaning.

You can also consider laying down linoleum or tiles if your dog continues to stain the flooring.

Know that the urine isn’t always isolated to just the carpet. There may be stains on walls, furniture legs, draperies, or mattresses. Be sure to clean all of these as well to completely tackle the odor and bacteria or chance for mold growth.