Cat, Human, and Environmental Health

In the past few decades, consumers, environmentalists, and health professionals have come to realize that there’s far more lurking in the cat box than odor. Medical professionals warn that silica, which is frequently combined with clay in modern cat litter, may cause respiratory problems; however, results from multiple studies have been  largely inconclusive. In addition, while silica provides high absorption, it also “gives no warning when saturated and liquid can pool in the box, has higher levels of toxicity, a tendency to roll and costs more,” according to Simon Moores.

Some clay-free litters, like the silica-based Pretty LitterTM, contain granules that measure the pH levels of cats’ urine, a kind of early-detection system for possible health problems such as urinary tract infections.






Declawed cats and their owners can experience cat litter in particularly vexing ways, especially post-op. Veterinarian Lynn Buzhardt explains that “cats use their claws to bury their eliminations. Litter sticks to the surgical sites, causing irritation, and exposes the foot to bacteria.” In these cases, veterinarians recommend the use of softer, dust-free litter, especially to discourage pain-induced elimination outside the box.


An infographic via the Center for Disease Control’s Public Health Image Library.

Cat litter can also cause health problems for humans if they fail to properly wash their hands or dispose of cat waste. Feline waste can carry the parasite Toxoplasmosis, or Toxoplasma gondii, and the Centers for Disease Control estimate that as many as 60 million Americans may be infected but have no symptoms. The parasite is particularly problematic for pregnant women. If they contract the parasite, their fetuses could experience ocular problems and even blindness. Writing for the medical journal The Lancet, J.G. Montoya and O. Liesenfeld report that this is only a problem if pregnant mothers have not previously contracted it: “maternal infection acquired before gestation poses little or no risk to the fetus.”

Public and environmental health converge when humans improperly discard cat waste and litter. Flushing cat litter down the toilet can introduce Toxoplasmosis into water sources, which then infects marine wildlife. Patricia Conrad, veterinarian and professor of pathology, microbiology, and immunology, gave an interview with Seattle-based Frolic Pet Services, explaining the many ways that the Toxoplasmosis parasite eggs, which are “amazingly tough,” invade the ecosystem. They are so tough, in fact, that “the procedures being used at most sewage treatment plants to treat wastewater from toilets ‘will not reliably kill’ the parasite’s eggs.” As such, the California Fish and Game Code Section 4501 explains that “several types of nonpoint pollution are harmful to sea otters.” The state legislature thus requires that cat litter packaging discourage consumers from flushing their litter, because “efforts to reduce the flushing of cat litter and cat feces are steps toward better water quality in the sea otters’ natural habitat.” The better health alternative, then, seems to be tossing used cat litter in the dump. Dr. Conrad notes another environmental problem with this solution: “We would like to reduce the burden on landfills…but we don’t yet have a good alternative.”

In spite of clay cat litter’s great popularity, the practice of strip mining the non-renewable resource has prompted many consumers and manufacturers to seek out earth-friendly alternatives. In 1984, the Wall Street Journal reported on one Florida man, owner of Green Mountain Products, Inc., who had great success with citrus fruit peels, after unsuccessful attempts with other natural products, “about 20 different materials, from sugar-beet pulp to pine bark.” In 2008, an article for the “natural wellness and conscientious living magazine” Mother Earth Living rated traditional and alternative litter types—including clay, silica, wheat, newspaper, pine, corn, and corncobs—according to criteria like renewability, post-surgery use, dust, and biodegradability. In a new era of earth-consciousness, many cat owners have in fact turned to the old, using natural materials—like newspaper—that were commonplace before the invention of cat litter.

Works Cited

Buzhardt, Lynn. “Declawing Cats: Controversy and Considerations.” VCA Animal Hospital (2015): VCA Hospitals.

Frolic Pet Services and Patricia Conrad. “Kitty Litter, Toxoplasmosis & You.” Frolic Pet Services (Jan. 5, 2015): Frolic Pet Services.

McNally, Misty. “The Scoop in Kitty Litter.” Mother Earth Living (2008): Mother Earth Living.

Montoya J.G. and O. Liesenfeld. “Toxoplasmosis.” The Lancet 363 (2004): 1967.

Moores, Simon. “Thinking Outside the Box: Cat Litter Materials Examined.” Industrial Minerals (2007).

Nazario, Sonia L. “Don’t Discard Those Citrus Peels: Your Cats Can Always Use Them.” Wall Street Journal (May 14, 1984): 29.

State of California Fish and Game Code, Section 4501. California Legislature.

Vetinfo. “Cat Declaw Litter: The Best Litter Materials for Recovery Time” (2018): Vetinfo.

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