Can a Dirty Litter Box Be Harmful to a Cat?

Can a dirty litter box kill a cat? No, but it can cause serious health issues for both you and your furry friend.

Feb 15, 2024byMonika Dimitrovska
can dirty litter box be harmful to cat

I won’t lie. I don’t enjoy cleaning out my cats’ litter boxes. However, I recently found out that delaying the whole thing can result in serious health conditions in both my family and pets. So, I decided to take the cleaning process more seriously.

Can a dirty litter box harm a cat? Yes, your furry friend can develop various infections. The same goes for you. Let’s learn more!

Human Health Risks

grey kitten in a box
Image credit: Pedro Candeias from Unsplash

A dirty litter box is a health hazard for both humans and cats. It’s also a happiness risk because cats don’t like dirty litter boxes. We understand that cleaning out your cat’s litter box might be unpleasant, but leaving it dirty for too long can make life much worse. Unfortunately, your cat’s dirty litter box can make you sick. You can experience several unpleasant illnesses, such as the following:

Cat Scratch Fever

Cat scratch fever attacks about 10,000 individuals each year, according to the Centers for Disease Control (CDC). And about 500 of those people stay in the hospital.

Kids under age nine and individuals living with weakened immune systems have a higher chance of catching this disease, which you can only get from a feline, not from another person.


The cat scratch fever first infects the animal, which may or may not display symptoms, before getting into the person cleaning the litter box.

The same goes for Salmonellosis. Symptoms of this disease include abdominal cramps, fever, diarrhea, and vomiting; it affects about 200,000 individuals in the US each year.

woman disinfecting hands
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Ammonia-Related Conditions

Ammonia is a toxic gas, and cat pee is rich in ammonia. So, breathing in cat urine can make you sick. If you breathe in cat urine constantly, you might experience headaches, asthma attacks, or even develop serious respiratory conditions, such as pneumonia.

Kids, senior individuals, and people with weak immune systems have a higher chance of experiencing illnesses because of too much ammonia.


Cat poop can sometimes contain parasites, such as roundworms. They can pass from your cat’s poop to you, resulting in diarrhea, weight loss, coughing, and nausea.

If you suspect your cat has roundworms, schedule a vet appointment immediately, and take extra caution when cleaning out their litter box.


Last but not least, toxoplasmosis is one of the biggest dangers of a dirty litter box. Cats can bear the toxoplasma gondii parasite and release it in their poop.

If you touch that poop, you could become infected. That’s why it’s so important to keep your cat’s litter box clean at all times. If you get infected, you may or may not show any symptoms.

Most people infected with this parasite think they have the flu. The worst part? Pregnant women can experience stillbirth or miscarriage as a result of toxoplasmosis.

Health Risks in Cats

cat sitting next to a window
Image credit: Eric Han from Unsplash

Can cats get sick from a dirty litter box? The answer is yes. Although your feline doesn’t sleep in their litter box, they can still get sick from it because they’re using it regularly.

If your cat sleeps in their litter box, it’s a problem, and you should schedule a vet appointment immediately.

Dirty litter boxes can cause urinary tract, bladder, and kidney diseases in felines. When your cat squats over a pile of poop, bacteria can move up the urethra, causing all kinds of problems.

The worst part? Urinary tract infections typically don’t cause symptoms in cats, so your furry friend could suffer a long time before you figure out there’s a problem. That’s why learning how to read your cat’s body language is so important.

Now, let’s discuss some of the most common health issues in cats who frequent dirty litter boxes.

Urinary Tract Infections

When your cat’s litter box doesn’t get cleaned properly, your cat might squat over and step in old poop and pee. The bacteria from lingering waste in the dirty litter box can go up the urethra, causing a UTI in your feline.

Symptoms of urinary tract infections in cats include frequent peeing but only releasing a small amount of pee, blood in the urine, increased licking of the urinary opening, peeing outside the litter box, difficulty peeing, and crying while peeing.

cat grooming on the couch
Image credit: Juan Gomez from Unsplash

Feline Interstitial Cystitis

Feline interstitial cystitis causes lower urinary tract disease. While the exact cause of this inflammation of the bladder isn’t known, stress is a crucial factor, including stress caused by a dirty litter box.

This type of stress can inflame nerves, including those that fill the bladder.

Symptoms of feline interstitial cystitis include difficulty peeing, peeing around the house, blood in the urine, crying while peeing, and frequent peeing.

Bladder Stones

Can a dirty litter box cause crystals? Unfortunately, yes, your feline’s dirty litter box can cause bladder stones. They form when organic materials and minerals accumulate in the bladder. And they’re typically the result of disease or inflammation.

Furthermore, bladder stones can block the urethra and cause difficulty peeing in felines. They’re often caused by urinary tract infections, often associated with dirty litter boxes.

Symptoms of bladder stones include difficulty peeing, chronic urinary tract infections, blood in the urine, painful peeing, peeing outside the litter box, genital licking, urine spraying, and urinary tract blockage (especially in males).

Your Cat Won’t Use a Dirty Litter Box

cat standing on a table
Image credit: Paul Hanaoka from Unsplash

Felines keep their fur and paws clean at all times, including stray cats out on the streets. So, the idea of frequenting a dirty litter box doesn’t sound that appealing to them, which is why they avoid dirty litter boxes in the first place.

Yes, your feline might use their dirty litter box once or twice. However, if forced to use a filthy litter box regularly, they will soon start peeing all over your bed, couch, etc.

Litter Box Cleaning and Maintenance Tips

owner cuddling orange cat
Image credit: Christin Hume from Unsplash

As we already established, cats hate dirty litter boxes. So, here’s a list of useful cleaning and maintenance tips:

  • If your cat litter isn’t good enough at blocking odor, switch it with a new brand, but transition between cat litter gradually.
  • Use protective gear (gloves and a face mask) to protect yourself against bacteria and toxic fumes.
  • Scoop litter and clumps at least once a day.
  • Refill litter every few days to ensure a proper level.
  • Keep 2”-3” of litter in the box, avoiding overfilling.
  • Empty and wash the litter box weekly with mild, unscented detergent. Rinse with warm water and, if needed, add white vinegar.
  • For crystal, clumping, or natural litter, replace monthly using a deep cleaning method. Use soap and vinegar, rinse, dry, and deodorize with baking soda or activated charcoal.
  • Avoid unnecessary harsh chemicals for a cat-friendly environment.


grey cat sitting next to flowers
Image credit: Josh Couch from Unsplash

All in all, a dirty litter box is a health hazard for everyone in the home.

Even if you use a covered box, you still need to scoop and clean it regularly. Cleaning the litter box is also super important for keeping your cat healthy, so just do it and spare yourself future headaches.

Monika Dimitrovska
byMonika Dimitrovska

Monika is a pet enthusiast and seasoned copywriter with a tech degree. She loves writing, but her heart belongs to her two mixed dogs, Buba and Bono, a mother-son duo. Bono’s siblings found loving homes, sparking Monika’s advocacy for neutering and deepening her curiosity about animal care.\n\nBut Monika’s pet family doesn’t end there. She also has two cockatiels and two rescue cats, proving her home is a haven for creatures big and small.