Tooth & Nail: There’s science behind your cat’s litter

Cat owners know there is a wide variety of litter brands and types in the marketplace.

Go with the cheapest, and the owner could be cleaning up litter on floors and carpets. The mess may not be only tracked, dry litter. It may include urine-caused muddy footprints that have dried. Dried bentonite clay is tough to remove from some surfaces.

Mining of bentonite clay has become more expensive than in the past. It wasn’t until the 1940s that Edward Lowe found that dried and granulated bentonite clay could, to some degree, trap and hold moisture and odors. Lowe made a fortune with his branded “kitty litter.”

Over time that hasn’t been good enough, and the cat litter market is now quite competitive.

If one adds a little sand or silica to the bentonite clay, the granules will clump together and prevent some tracking around the home. This was the discovery made by Thomas Nelson. He branded it “clumping cat litter” and made a fortune as well.

On the other end of the cost spectrum are cat litter products made with silica gel. Silica gels are technically known as synthetic amorphous silica, or SAS for short. For decades, SAS has been used in topical and oral medications for both humans and animals. It is also used in foodand cosmetics.

Sourcing the silica is also important for specific uses. As a mineral, calling something silica is sort of like saying guests arrived in a “conveyance,” versus saying they arrived in a Ford sedan.

Fundamentally, silica is any of a number of forms of silicon dioxide. This family includes quartz, which is the most common. Synthetic forms were also created in recent years.

Silica gels used for cat litter are spherical structures and feature an open lattice that holds and traps both the odor and the liquid. Eventually, the urine evaporates but the odors still remain bound up mostly in the silica gels. This is one reason the gels are marketed as lasting for 30 daysor more.

Another benefit of the silica gel litters is they weigh far less than the bentonite clay litters. That’s easier on all the people in the supply chain packing the stuff around. It also means the containers used to sell silica gels can use less plastic and less fuel to ship.

Overall, some argue that the silica gels are a greener alternative to all previous cat litter compositions. If one considers the entire production chain, marketing, sales, shipping, and disposal, that may or may not be true.

One brand available now also incorporates proprietary additives that change colors when a cat with certain metabolic disorders pees on it. A dark yellow to olive green color means that at least the urine indicates thecat is “normal.”

If the litter displays an orange color, it may mean your feline has metabolic acidosis or acidosis in its kidney tubules. A blue color appears if the urine is abnormally alkaline. This can be an indicator of urinary tract infections or that kitty has an increased risk of urinary stone formation.

Red on the litter indicates there is blood in the urine. That may come from crystals in the urinary tract, other lower urinary tract disorders or certain types ofkidney disease.

The silica gel litter with color indicators weighs less than any other brand on the market, can last up to 30 days and can be acquired through a subscription service so one never runs out.

Waste materials like sawdust pellets have been tried as litters but haven’t grabbed a big share ofthe market.

Powell is the public information officer for the Washington State University College of Veterinary Medicine, which provides this column as a community service. For questions or concerns about animals you’d like to read about, email cpowell@vetmed.wsu.edu.