Is Cat Urine Toxic? The Dangers of Feline Waste

Cat urine contains compounds that can be harmful if ingested or inhaled by humans. This article provides an overview of the components of cat urine, diseases that can be transmitted through cat urine exposure, and the effects that cat urine toxicity can have on the body. According to pet ownership statistics, cats are popular pets, with 29-38% of American households owning cats. With widespread cat ownership comes potential exposure to cat urine, whether through inadequate litter box hygiene or urinary marking behaviors. Understanding the risks and preventative measures is important for any cat owner or person exposed to cat urine.

The purpose of this article is to comprehensively explore the potential toxicity of cat urine to humans. It will analyze the chemical composition of cat urine and examine scientific evidence on health consequences like skin irritation, respiratory issues, and neurological symptoms. The article strives to be insightful yet accessible for the average reader. By synthesizing research and expert perspectives, it aims to leave readers fully informed on this topic relevant to millions of cat owners.

Components of Cat Urine

Cat urine is composed primarily of water, with other key components including urea, uric acid, creatinine, and ammonia. Of these, ammonia is often responsible for the strong smell of cat urine (1).

Water typically makes up 80-90% of cat urine. The remaining portion contains an array of waste products that the kidneys filter out of the bloodstream.

Urea and uric acid are nitrogenous waste products from protein metabolism that cats need to excrete. Creatinine is a metabolic waste product from muscle activity.

Ammonia is produced by the breakdown of urea. It is volatile and alkaline, giving cat urine its pungent odor. The strong ammonia smell serves a purpose – it acts as territorial marker for cats (2).

cat urine in litter box

Other minor components of cat urine can include amino acids like felinine, enzymes, hormones, and pheromones used for communication.

Diseases Transmitted Through Cat Urine

Several diseases can be transmitted through exposure to cat urine. Two of the most concerning are toxoplasmosis and campylobacteriosis.

Toxoplasmosis is caused by the parasite Toxoplasma gondii, which cats can transmit through their feces. Although cats usually only shed the parasite for a short period of time, T. gondii oocysts can survive in cat litter or soil for over a year. Humans can become infected by accidentally ingesting contaminated cat feces or material contaminated with cat feces. Pregnant women are at highest risk since toxoplasmosis can cause birth defects. Most infected people show no symptoms, but toxoplasmosis can cause flu-like illness, blurred vision, and neurological problems in some cases.

Campylobacteriosis is a bacterial infection that cats and other animals can transmit through their feces. The bacteria does not usually make cats sick but it can cause diarrhea, abdominal pain, and fever in humans. Campylobacter spreads through contact with contaminated feces, food, or water. Good hygiene like washing hands after cleaning litter boxes is important to prevent infection.

Ringworm is a fungal skin infection cats may carry. The fungus can be spread between animals and humans through direct contact with broken skin and possibly contaminated surfaces. Ringworm causes red, itchy, scaly skin lesions in people. Keeping cats’ claws trimmed and avoiding prolonged skin contact can reduce transmission risk.

Effects of Inhaling Ammonia in Urine

Cat urine contains ammonia, which is released in the form of gas. Exposure to high levels of ammonia gas can cause irritation of the respiratory tract. According to, even minor exposure to ammonia can lead to “queasiness, lightheadedness and headaches.” At high concentrations, ammonia gas is severely irritating and corrosive to the respiratory tract. Inhaling ammonia can cause coughing, wheezing, chest tightness, and shortness of breath.

person coughing from ammonia exposure

Long-term exposure to ammonia from cat urine, especially in poorly ventilated spaces, carries more significant health risks like asthma and other chronic lung conditions. The CDC states that “breathing ammonia can irritate the lungs, causing coughing and/or shortness of breath.” Severe cases can lead to swelling of the throat, burns, and lung damage.

Skin Reactions to Cat Urine

Cat urine can cause various skin reactions in humans, ranging from mild irritation to severe dermatitis. The most common reactions are:

Rashes – Exposure to cat urine can lead to contact dermatitis, presenting as red, itchy rashes on the skin. This is often caused by allergens in the urine such as fel d 1 protein.

skin rash from cat urine

Hives – Some people develop hives or urticaria after contact with cat urine. This is an immune reaction that leads to swollen, red welts on the skin.

Irritant dermatitis – Cat urine contains ammonia which can irritate and inflame the skin, especially with repeated exposure. This can result in symptoms like redness, stinging, and peeling skin according to VCA Animal Hospitals.

Urine scald – When urine contacts and burns the skin, it can cause urine scald or crusty, irritated patches of skin. This is common in elderly or paralyzed cats unable to move away from their urine according to an article in Lab Animal journal.

Gastrointestinal Effects

Inhaling the ammonia in cat urine can irritate the gastrointestinal tract and cause nausea, vomiting, and diarrhea in humans. According to Poison Control, the high ammonia content of cat urine can be toxic if inhaled in high concentrations. Ammonia is a colorless gas that is released from cat urine as it breaks down. When a person inhales ammonia, it can cause the linings of the mouth, throat, and gastrointestinal tract to become inflamed and irritated.

One of the most common gastrointestinal symptoms from inhaling cat urine ammonia is nausea. The nausea occurs as the ammonia irritates the stomach linings and triggers the vomiting reflex. Vomiting may occur immediately or be delayed for hours after exposure. The ammonia can also cause inflammation and diarrhea by irritating the linings of the intestines. According to The Hidden Dangers of Cat Urine and Feces, the gastrointestinal effects of inhaling cat urine tend to be temporary and resolve once the person is removed from the source of exposure.

Neurological Effects

Inhaling ammonia from cat urine over time can lead to neurological issues in humans, especially headaches, confusion, and loss of coordination.

One study published in Gizmodo article found that the parasite Toxoplasma gondii, which is often transmitted to humans through cat feces, can cause inflammation in the brain leading to neurological disorders like schizophrenia, autism, and Alzheimer’s disease.

Exposure to the parasite may also alter neurotransmitter levels like dopamine in ways that affect motor control and coordination. A 2011 study in the National Center for Biotechnology Information article showed gender differences in neurological reactions to cat urine odors, indicating a biological response.

Headaches from inhaling ammonia over time occur as it irritates the linings of the nose and throat. At high concentrations, ammonia can cause central nervous system depression leading to confusion, loss of coordination, and other cognitive deficits.

Who is Most at Risk

Certain groups of people are at higher risk for health issues from exposure to cat urine.

Pregnant women are at risk as toxoplasmosis, a disease that can be transmitted through cat feces, can cause birth defects and miscarriage. Cats are the primary host for toxoplasmosis [1].

Young children are also susceptible as their immune systems are still developing. Exposure to the ammonia in cat urine can cause asthma attacks in children [2].

Those with weakened immune systems, such as people with HIV/AIDS, cancer, or on immunosuppressant drugs are at higher risk for toxoplasmosis and other illnesses from cat urine and feces [1].


The most important treatment for exposure to cat urine is thorough cleaning and disinfecting. Cat urine can soak into soft materials like carpet, upholstery and mattresses, so these items may need to be replaced if the urine has saturated them. Hard surfaces like floors and walls should be cleaned with soap and water to remove all organic material. A disinfectant designed to kill bacteria and break down uric acid crystals should then be applied. Disinfectants containing enzymes are best for breaking down the urine. Allow adequate contact time for the disinfectant per the product instructions. Be sure to provide adequate ventilation when cleaning.

If irritation or respiratory issues develop after exposure to cat urine, see a healthcare provider. Antihistamines, inhalers, nebulizer treatments or steroids may help relieve symptoms. Those with asthma may need adjustments to asthma medications after exposure. For skin rashes, topical hydrocortisone and anti-itch creams can provide relief. Keep rashes clean and covered to prevent infection.

In cases of toxoplasmosis infection, medications are available to treat the parasite. Treatment may include pyrimethamine and sulfadiazine for several weeks to clear the parasite. Medications come with potential side effects, so work closely with your healthcare provider if toxoplasmosis is suspected. Preventing exposure is imperative for those with compromised immune systems.





There are several ways to help prevent exposure to the toxic compounds in cat urine:

Litter Box Hygiene

Keeping the litter box clean is crucial. Scoop out waste from the litter box daily and change the litter completely at least once a week. Use litter that clumps well and masks odors. Place litter boxes in low-traffic areas of the home. Consider using litter deodorizers as well.

cat litter box and scoop

According to, having enough litter boxes for the number of cats and cleaning frequently prevents buildup of ammonia.


Ensure rooms where cats spend time are well-ventilated to allow ammonia gases to dissipate. Use exhaust fans, open windows, and air purifiers.

As recommended by, avoiding closed, stagnant air spaces reduces ammonia accumulation.

Handling Waste Safely

When cleaning the litter box, wear gloves and a mask to prevent skin exposure and inhalation. Seal and dispose of waste properly. Clean any affected areas thoroughly with an enzymatic cleaner to neutralize odors.

According to, gentle cleaning products help eliminate ammonia without releasing more into the air.

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