Clay-Free Cat Litter for Pet Sustainability

Do our feline companions really have tiny carbon paw prints?

Cats clean themselves and cover their poop. They aren’t fossil-fuel-needy. No gas-guzzling trips to doggie day care or dog parks for them. We seldom buy our cats manufactured collars, leashes, or chew toys.  And just try dressing up your cat in a polyester costume!

The only thing an indoor cat really wants from you is love, attention, and meat. Not as much meat as dogs; nonetheless some eco-system straining meat. No wonder you see so few online posts about greening up cats. By their very nature cats live near zero waste lives. Or do they?

Cats have surpassed dogs as the most popular pets in U.S. households. We host 96 million cats versus 83 million dogs. Cats have fastidious toilet habits, but require a litter box with granular “stuff” to fulfill their missions.  And they need a willing human partner to buy litter, clean the box, and dispose of the waste.  That would be you. And here’s where you can make a real difference in sustainable stewardship.

The average cat produces 1/3 lb. of waste and used litter per day or 120 lb. per year. If you have three cats, that’s 1 lb. per day, 7 lb. per week, or 365 lb. per year. That’s quite a load of ballast in the trash bag.  And that’s not counting deep box cleanings that involve dumping and replacing all of the litter.

Statistically speaking, 96 million U.S. cats generate around 500,000 dump trucks full of waste and used litter a year. Because some cats spend time outdoors, there’s no way to be sure how much kitty fallout is trashed.  Whatever the amount, it’s clear that indoor cats are hardly near-zero-waste pets. Each year millions of tons of feline waste, litter, and plastic collection bags stream into waste management systems.

A smattering of cities, mostly Canadian, accept pet waste, litter, and bedding for composting or biodigestion processing as part of their organics recycling systems. These cities include Calgary and Red Deer, Alberta; Halifax, Nova Scotia; and Toronto, Ontario.   While community-wide programs offer the best solution for pet waste sustainability, chances are good that when you dispose of cat waste, the material will simply be hauled to a sealed landfill where it will degrade slowly and emit methane.

Downsides of Clay Litter

It’s easy to see why clumping clay litter is appealing to cat lovers. Cleaning up chunks of compacted clay is easier and more economical than waiting for the clay to reek of urine then dumping the entire litterbox.  To combat odor, manufacturers often add fragrance to litter, although these products are trending to “fragrance free” (baking soda or “natural odor elimination” or “botanical ingredients”).

The downside? Critics say that clumping clay litter is unfriendly to the earth because a major constituent, sodium bentonite, is obtained through strip mining. Sodium bentonite absorbs urine and swells to 15 to 18 times its dry size, so it is often used in sealing and grouting materials.  Non-clumping clay litters often consist of quartz silica, crystalline silica or silica gel, sands which simply absorb moisture. Crystalline silica, or silica dust, is treated as a known carcinogen under California’s Proposition 65. Cats ingest these materials when they lick their paws or breathe litter dust into their lungs. Ingredients are listed on clay litter packaging, but simply ditching clay is easier than deciphering the contents.

Inexpensive Alternative

Our cat Max has been clay-free for five years. When we adopted Max as a kitten, the staff told us that he was healthy but had been treated for a respiratory illness when he entered the shelter.  After we brought him home he seemed fine, but his eyes watered constantly and he had occasional sneezing fits to clear his sinuses.  When we eliminated clay litter, his sneezing stopped and his eyes watered less frequently.

When looking for a clay-free alternative for Max, we considered do-it-yourself natural litters like wood shavings, sand and soy-ink newspaper strips, but they were inconvenient and required frequent changing. We checked out environmentally friendly options on the market, like corn, wheat, wood, and paper-based litters. But for the most part, these products were more expensive than clay.

We finally found a great choice that didn’t break the bank: small animal bedding. You can buy these natural pine pellets in 35 lb. (1 cu. ft.) bags at your local feed store for around $6.00. We mixed the pellets with Max’s clay litter, gradually eliminating the clay. I’m not sure that approach was necessary. He’s a pretty resilient guy and now seems to love the scent when we add fresh pine pellets.

If you decide to try this bedding, examine the bag carefully before purchasing. If you don’t see much sawdust, you’ll know that the plastic bag was properly sealed and kept dry through transport and storage.  Don’t confuse bedding pellets with the bagged pellets used to fuel heaters. Fuel pellets are often smaller and more likely to slip through slotted litter scoopers.  This is a key consideration when cleaning a litterbox with pellets – a process that’s easy but very different from scooping clay litter.

Cleaning a pellet litterbox takes some finesse and requires a deep, extra wide (5 in.) scooper. Here’s how to do it.  Lift out the poop and deposit it into a holding bag or bin.  Then carefully scoop out some of the lightly clumped urine-soaked sawdust dampened pellets.  Shake the scooper back and forth over the holding container.  Tapping the side of the scooper to the side of the litter box will help sift out the loose sawdust more quickly.   You can then recycle the intact pellets left in the scooper by returning them to the litter box. (I’ve posted a link to another cleaning approach for pellets,  the All Pine Self-cleaning Litterbox, at the bottom of this article.)

Pine pellets stay fresh and need little replenishing when used as litter. To enhance the natural freshness, you might want to sprinkle in bokashi mix (EM-impregnated grains used to ferment organics).  I’ve found that using the pellets in combination with bokashi mix and cleaning Max’s litterbox twice a day has eliminated the need for trashing an entire box of used litter.

Choosing any organic-based litter helps to tamp the brakes on clay litter manufacturing, distribution, and sales, but there’s an even better reason for switching litters.  An elegant reason.  A reason guaranteed to generate good eco vibes and keep you from sliding back to clay for the sake of convenience. All you need to do is go one step further. Now that you’re using organic litter, you can recycle the whole enchilada.

Closing the Litter Sustainability Loop

If you own or have access to property with trees, bushes, and other ornamental plants, recycling your cat’s waste and litter will provide them with a nutritious soil amendment. And yes, it is safe to process this material, and send the waste back to nature.

Some cats, particularly outdoor cats that hunt rodents or eat raw foods, can be primary hosts of feline-specific parasites. The most stubborn and dangerous is the protozoan parasite Toxoplasma gondii.  An estimated 11% of Americans have dormant Toxoplasma cysts in their brains and in some countries, the rate is 90%. Healthy immune systems keep the parasite at bay.  But infants, pregnant women, and people with compromised immune systems who come in direct contact with cat feces can become afflicted with toxoplasmosis, a serious and occasionally fatal disease.

Because there’s always a chance of spreading germs, use due diligence when recycling feline poop. Wash your hands. Keep equipment used to process pet waste separate from equipment used for growing fruits, vegetables, and herbs.

That said, cat waste mixed with corn, wheat, paper, and wood-based litter can be composted like any other organic material. Follow the instructions available through your local agricultural extension. You may need to add food scraps or other “green” material to the pile to offset the abundant “brown” litter.  But including the litter is a plus because it serves as a carbon bulking agent and the ammonia in the urine will help with degradation.

Your back yard compost pile will probably not heat up to the sustained 122 degrees required to kill carnivore poo pathogens. So let finished cat poo compost lie dormant (“season“) for at least 18 months before using it to enrich soil. Never use it on or near edible gardens because contaminated compost might cling to harvested foods.

Another recycling option is simply burying the waste and litter – either loose or in open paper bags – at least six inches deep in an area that does not drain into waterways. You can plant landscaping over the buried pet waste after letting it degrade for six or more months.  Install new plantings well above buried waste. Raw manure and litter are too strong for direct exposure to young roots. You can also bury waste and litter in very small pockets around mature shrub or tree roots.  The material will degrade and provide nutrients to the soil.

While “flushable” cat litter is available, flushing is not a good disposal option for kittens or cats who might be infected with T. Gondii. This persistent parasite can be fatal to marine mammals.  If you’re not sure if your cat is a T. Gondii carrier, don’t recycle feline waste using do-it-yourself pet waste septic bins or commercial systems such as Dog Dooleys that might drain into watersheds.

Since most infected cats show no symptoms, only a test will reveal contagion. If your cat tests positive for antibodies to T. gondii and you keep the cat indoors afterwards, it’s unlikely that your pet will shed infectious oocysts. Flushing and septic bins are safe options only for cats that are not infected.

You may also want to explore the possibilities of recycling pet waste via vermicompost (worms) or bokashi (fermentation). These are trickier methods that, like composting and burial, require a yard and plants that will benefit from the fertile residue. But if you’re determined, curious, and game for a new adventure, you can find online videos and instructions that will point you in the right direction.

By sending your household’s cat waste back to nature, you’ll shift consumer dollars from clay to organic litter, help divert waste from landfills, improve the soil, and take your cat to near zero waste.

Pet Population

U.S. Humane Society, 96 million cats in the U.S.

Dump truck math / cats

96M cats X .3 = 28,800,000 lbs. per day or 10,368,000,000 lbs. per year or 5,184,000 tons per year or 5.2M tons of cat waste per year 5,200,000 tons divided by 500,000 = 10.4 tons, average dump truck capacity

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