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Why Does Cat Urine Smell Like Ammonia? 5 Vet Reviewed Reasons

Written by: Jordyn Alger

Last Updated on June 6, 2024 by Catster Editorial Team

Why Does Cat Urine Smell Like Ammonia? 5 Vet Reviewed Reasons


Dr. Lauren Demos (DVM) Photo


Dr. Lauren Demos (DVM)


The information is current and up-to-date in accordance with the latest veterinarian research.

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Cat owners who use effective cat litter and clean the litter box frequently don’t tend to have issues with cat urine odor. However, some cat owners still struggle to manage the prominent odor of their cat’s urine.

Cat urine has a distinct scent since it contains ammonia, but it’s not overpowering in healthy cats. There are five likely reasons that your cat’s urine creates a strong odor. In this article, we will discuss these possibilities so that you can make your home smell fresh and clean again.

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The 5 Reasons Why Cat Urine Smells

1. The Urine Has Been There a Long Time

If your cat’s litter box has a pungent odor, consider how long the urine has been left there. Cat urine, when left uncleaned for long periods, will eventually give off a pungent stench.

Some cat litters do a good job of masking these odors, but if left long enough, the stench will eventually overpower the litter. Cleaning your cat’s litter box regularly will keep the odor at bay. If you already clean your cat’s litter box on a regular basis, check your house for signs that your cat may have urinated outside of the litter box.

cat coming out of a litter box
Image Credit by: Natasha Zakharova, Shutterstock

2. Your Male Cat Is Unneutered

Unneutered male cats have stronger-smelling urine than the average cat. Unfixed male cats have powerful hormones that are eliminated along with their urine. When an unneutered male cat urinates somewhere, the stench is incredibly difficult to remove.

Neutering your cat can minimize the stench of his urine, and it has other benefits. Neutered cats display fewer behavioral issues, such as aggression and roaming. To have your cat neutered, talk to your vet about when the procedure would be right for your pet.

3. Your Cat Has Urinated Outside the Box

When cats urinate outside the litter box, there is nothing to mask the odor. For instance, if your cat is injured and it affects their mobility, they may go to the bathroom on the floor if the litter box is difficult to access. When they go in several places in your house, the ammonia odor will increase until you clean the areas thoroughly. Cats may also urinate over the edge of the box if it is too small, or outside the box if they have an infection, or don’t like the litter or box location.

4. Your Cat Has a Urinary Tract Infection

Unfortunately, urinary tract infections are common health issues in cats, and they can cause changes in how urine smells. If your cat’s bathroom habits change, taking them to your veterinarian is vital since a urinary infection can worsen and cause other severe conditions.

vet holding a senior cat
Image Credit: Alive Rodnova, Shutterstock

5. Your Cat’s Litter Isn’t Designed to Fight Odors

Although cat litter products seem fairly straightforward, some brands are more effective than others. Cat litter can be made from clay, crystals, recycled paper, wheat, and other materials.

If you can smell your cat’s urine from the litter box, check the litter you use to verify whether it suppresses odors. If it doesn’t, switching your litter to a type that can cover odors may help.

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Cleaning Cat Urine Properly

To keep your cat’s litter box from becoming smelly, scoop it every day or more and change the litter entirely every other week. Before filling the box, scrub it with soap and water to remove the stains and odors.

If your cat has urinated outside the litter box, you’ll need to clean the urine as soon as possible. The longer the urine stays, the worse the stench will become. Cleaning the urine properly ensures your cat doesn’t return to the soiled spot to urinate again.

An enzyme cleaner will be necessary to fully break down the urine, eliminating the odor and reducing the chances that your cat will return to urinate at that spot again.

Combating tough cat litter smells is an ongoing battle for pet parents but luckily, there are products out there designed to help! Two products that significantly reduce odors are the Hepper Litter Additive and the Hepper Enzyme Spray. Find out which is better suit to your needs with our breakdown of each product below. 

Hepper Enzyme Spray - New Label Hepper Litter additive
Hepper Advanced Bio-Enzyme Pet Stain & Odor Eliminator Spray Hepper Advanced Bio-Enzyme Cat Litter Deodorizer Powder
Eliminates smells
Eliminates smells:
Eliminates smells:
Removes stains
Removes stains:
Removes stains:
Light fresh scent
Light fresh scent:
Light fresh scent:
Works on multiple surfaces
Works on multiple surfaces:
Works on multiple surfaces:
Neutralizes odor within cat litter
Neutralizes odor within cat litter:
Neutralizes odor within cat litter:

At Catster, we’ve admired Hepper for many years and decided to take a controlling ownership interest so that we could benefit from the outstanding designs of this cool cat company!

Monitoring Your Cat’s Bathroom Habits

Taking your cat to the veterinarian is the first step when you notice their bathroom habits have changed. If you scoop the litter daily and frequently clean the box, a strong ammonia smell may result from a health issue.

You can buy litter that changes color when the urine’s composition changes, but it’s better to monitor your cat’s habits closely, maintain regular veterinary appointments, provide healthy food and fresh water, and follow your veterinarian’s treatment if they’re sick or injured.

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Final Thoughts

Cat ownership comes with pleasant experiences, but cleaning up urine isn’t among them. However, with a diligent cleaning schedule and high-quality cat litter, the odor of your cat’s urine shouldn’t carry throughout the house. If your cat’s urine suddenly begins to create a strong stench, reach out to your vet to rule out the possibility of a medical issue.

Featured Image Credit: Pixel-Shot

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