Can You Smell Cat Pee In Litter Box?

Many cat owners notice an unpleasant ammonia-like odor coming from their cat’s litter box. This odor can be quite strong and pervasive, filling the home with an unpleasant smell. While some smell is inevitable with a litter box, a very strong urine odor can indicate potential health or behavioral issues with your cat.

Understanding the source of litter box odors and how to reduce them is important for any cat owner. Not only can strong odors be unpleasant, but they may also indicate that your cat is having issues with inappropriate elimination outside the litter box. By taking steps to reduce litter box smells, you can keep your home fresher while also looking out for your cat’s health and wellbeing.

Causes of Cat Urine Odor

There are several potential causes that can make your cat’s urine have a particularly strong odor. Understanding the root cause can help you address the problem effectively.

Certain medical conditions like kidney disease, diabetes, urinary tract infections, or tumors can alter the chemical composition of a cat’s urine, leading to a strong ammonia-like smell (1). Elderly cats are especially prone to kidney issues that affect urine odor.

Inadequate or improperly cleaned litter boxes are another culprit. Urine can soak into the box and litter, releasing smells over time. Insufficient cleaning allows odor to build up. Using scented litters can also make the smell worse when mixed with urine (2).

Finally, improper litter box habits can be an issue. Some cats may urinate outside the box due to medical problems, stress, or dislike of the litter box location or environment. This can leave urine in hard to reach places that leads to lingering odors (3).

If your cat’s urine has a persistent, strong smell, have your vet examine them to rule out medical issues. Ensure litter boxes are sufficiently cleaned and provide an appealing setup. Monitor your cat’s habits to identify any outside the box urination.

Cat’s Sense of Smell

Cats have a much stronger sense of smell compared to humans. Their sense of smell is about 14 times better than humans. This means cats experience smells at a much higher intensity than we do. According to research from McGill University, the urine from male cats can be particularly pungent due to the presence of felinine, a compound that promotes territorial marking. The strong ammonia-like odor from cat urine is just as bothersome to cats as it is to humans.[1] In fact, cats keep themselves meticulously clean specifically to avoid smelling urine odors on their coat.

A urine odor lingering in the litter box can be a nuisance for cats and deter them from using it. Cats like their litter boxes to be clean and odor-free. If the smell bothers you, it’s a sign your cat’s litter box needs cleaning and deodorizing. Take action promptly, as ignoring the smell means your cat must tolerate an unpleasantly smelly bathroom.

Health Risks

Cat urine contains ammonia, a colorless gas with a very pungent, irritating odor. Exposure to high concentrations of ammonia in the air can cause irritation and damage to the eyes, skin, and respiratory tract in both cats and humans.

For cats, long-term exposure to ammonia from urine odor trapped in a dirty litter box can lead to upper respiratory issues like asthma. The ammonia gas irritates the delicate tissues of a cat’s nose, throat, and lungs.

In humans, breathing ammonia from cat urine over time can also exacerbate respiratory issues like asthma and allergies. The gas triggers inflammation in the lungs and airways, making breathing more difficult [1]. Ammonia inhalation is also linked to headaches, nausea, and fatigue.

While exposure to trace amounts of ammonia from properly cleaned litter boxes is not typically dangerous, consistently breathing high levels of ammonia from unclean boxes can pose more serious health risks. These include lung damage, blindness, and even death in extreme cases. Proper litter box maintenance is crucial.

Litter Selection

When selecting a litter for odor control, you’ll need to decide between clumping and non-clumping varieties. Clumping litters form solid clumps when wet, which makes it easier to scoop out urine and feces. The clumps also trap odor inside, helping limit the smell. Popular clumping litters include Purina Tidy Cats, Dr. Elsey’s Precious Cat, and Arm & Hammer Clump & Seal.

Non-clumping litters typically use crystals or pellets that absorb liquid but don’t form clumps. While they can help suppress odors, the urine stays spread throughout the litter. You’ll need to frequently replace the entire box instead of just scooping. Some top non-clumping litters are World’s Best Cat Litter and Feline Pine.

When it comes to scent, some cats prefer unscented litter with no perfumes or fragrances added. But scented litters can help mask unpleasant litter box odors between changes. Look for subtle, natural scents like lavender, citrus, or pine if your cat tolerates it. Avoid heavy perfumes that may irritate cats’ sensitive noses. Products like Arm & Hammer Clump & Seal offer light baking soda fragrance.

Litter Box Setup

Proper litter box setup is crucial for reducing unpleasant odors. The key factors to consider are box size, location, and number of boxes.

Larger litter boxes allow more room for digging and burying waste. Boxes should be 1.5 times the length of the cat (Source). Insufficient room can cause cats to miss the litter or kick it outside the box.

The box location should be quiet, private, and easily accessible. Avoid high traffic areas and loud appliances. Place it away from food and water bowls (Source).

Multi-cat households should have one more litter box than the number of cats. This prevents crowding and territorial issues. Separate boxes in different rooms or floors of the home.

Cleaning Litter Box

To keep your cat’s litter box smelling fresh, it’s important to clean it frequently and thoroughly. The general recommendation is to scoop solid waste from the litter box daily. According to veterinarians, you should replace all litter at least every two weeks, or sooner if you notice strong odors (

For the daily cleaning, use a scoop to remove all solid waste and clumps from the litter. Scoop waste into a waste bag for disposal. Be sure to remove all waste from corners and edges of the box. After scooping, check the litter level and add fresh litter as needed to replace what was removed. Gently mix the fresh litter into the old litter.

Every 1-2 weeks, dump out all used litter and thoroughly wash the litter box with soap and hot water to remove odors. Rinse well and allow to fully dry before adding fresh litter. Replace worn out boxes as needed.

For multi-cat households, some sources recommend scooping more than once per day and doing full litter changes more frequently such as every week ( The frequency will depend on the number of cats, size of litter box, and personal preference.

Deodorizing Litter Box

There are several effective ways to deodorize a litter box and reduce unwanted odors:

Baking soda is an excellent natural deodorizer that is safe for cats. Sprinkle a thin layer of baking soda at the bottom of the litter box before adding the litter. The baking soda will help absorb odors and keep the box smelling fresher. According to this source, baking soda can neutralize urine odors.

Activated charcoal is another great odor absorber. Place small charcoal bags or charcoal filters around the litter box to help trap smells. Replace the charcoal every few weeks when it is saturated. Some litter brands also make charcoal-infused litter that can cut down on odors.

Cleaning the litter box regularly with white distilled vinegar will help eliminate odors and disinfect the plastic. The vinegar smell dissipates quickly but works to remove urine odors. Rinse the box after cleaning and allow to fully dry before refilling with litter. Vinegar can be combined with baking soda for an extra strong cleaning solution.

When to Seek Help

If you have tried the various cleaning and odor removal methods but your cat’s urine smell persists, this indicates an underlying medical issue likely needs to be addressed. According to Pet Health Network (, abnormal cat urine smells can be caused by a urinary tract infection, kidney disease, diabetes, or other medical conditions. If the litter box smells strongly of ammonia despite your cleaning efforts, take your cat to the veterinarian for a checkup. They can run tests on your cat’s urine to diagnose any issues. As HuffPost reports (, you should not try to mask a persistent urine odor with shampoos or sprays – seek professional veterinary help to address the root cause.


In summary, controlling cat urine odor in the litter box is important for the health and wellbeing of both you and your cat. Cats have a powerful sense of smell and can be deterred from using a dirty litter box. Breathing in ammonia from concentrated urine over time can cause respiratory issues for humans. It’s essential to choose the right litter material, set up the litter box properly, clean it frequently, and use deodorizing products when needed. Most issues with odor and inappropriate elimination are preventable with good litter box management.

If odor persists despite your best efforts, don’t simply mask it with strong fragrances. Have your veterinarian check your cat’s health, as this could signal an underlying medical issue. Make sure your cat feels comfortable with the type and location of their litter box. A clean, pleasant litter box environment will encourage good litter habits and maintain a fresh home for both you and your feline friend.

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