Diatomaceous Earth

Diatomaceous earth, composed of silica, is a more natural way to supplement calcium, in a form the body can utilize.

By Heather Smith Thomas

Diatomaceous earth is being used by a growing number of horse owners for a variety of purposes, including parasite control and as a source of silica. Judy Sinner, Communications Director for Dynamite Specialty Products (a company that uses diatomaceous earth in some of its products), explains that this substance is composed of "leftovers from prehistoric sea vegetation" that accumulated at the bottom of large bodies of water. "It is a silica powder - the fossils of the dead diatoms. It is also called fossil flour. Diatoms are basically one-celled plants, with silica as their cell walls. This primitive plant has 2 parts that fit together, looking like a little pill box - microscopic, of course. That's why they are called diatoms; dia meaning 'two'."

These deposits were formed in ancient sea beds, in Idaho and other areas in the West that used to be covered with water. The diatomaceous earth beds were created by the algae remains, building up over thousands of years. This sediment resembles chalk, but the material is much lighter in weight.

"The great thing about silica powder is that the body has the ability to transmute organic silica into calcium," says Sinner. "Calcium is the most prevalent mineral on the planet and in our bodies, and silica is not far behind. It is basically what gives plants their stiffness and flexibility." Grass contains a lot of silica; that's why it wears down horse's teeth; it's more abrasive than soft-leafed alfalfa, for instance.

"When you think about things like where a dairy cow gets all the calcium she cranks out as in milk over the years, there's not nearly as much calcium going into her body (in the form of calcium) as she is putting out in the milk, and the answer is silica - from the plants she eats. So diatomaceous earth is a great way to supplement calcium, in a form the body can use or not, as needed. This is better than force-feeding too much of a calcium supplement that might upset the calcium-phosphorus ratio in the body. Diatomaceous earth is a more natural way to do it, in conjunction with a balanced mineral program."

Sinner's father is an osteopathic physician, she says, "and has physician friends in India. He says they are far ahead of us over there, because they can heal fractures in about half the time we do here, by putting people on silica when they break a bone."


She says silica is a powder from sedimentary rock. All rocks have a magnetic charge, according to Harvey Lisle, author of the book The Enlivened Rock Powders. "They are either paramagnetic or diamagnetic. Lisle says silica is paramagnetic. A lot of people use diatomaceous earth as a natural wormer. It works several ways. Because it is a silica, it is microscopically sharp - not on a level that would hurt a horse internally, but theoretically it scratches and perforates the protective coating on intestinal parasites and makes them dehydrate," she says.

"Secondly, it helps in that if animals are calcium deficient, they are more prone to parasite infestation. Thirdly, parasites are diamagnetic, so they are actually magnetically repelled by the diatomaceous earth. So there is a subtle magnetic frequency that causes the parasites to avoid it," according to Sinner.

"Wild horses are often seen eating clay and rock deposits, and rock dust. They seem to know how to deworm themselves if they have access to that type of thing. Rock dust has a magnetic charge or nutrient level they recognize as beneficial. Clay soil is the same way, being paramagnetic." Clay is ancient volcanic ash.


" You'll see horses eat dirt, and people think it's a mineral deficiency, but the horses may also be parasite infested, or toxic. Clay has a strong negative charge, and can absorb a lot of toxins; chemical toxins usually have a positive charge. A gal called me the other day for advice. She had just built a new indoor arena. Her horses were on a diet containing a lot of sweet feed and a huge amount of supplements, and were pawing through the tanbark and eating holes in the clay floor of her new arena. One horse got out and only went as far as the wood fence in her driveway and was devouring the fence." Horses often chew wood when short on roughage, and also when short on phosphorus, since wood is high in phosphorus. She says horses that lack phosphorus will eat wood "like crazy", and when adequate phosphorus is added to their diet, they usually quit chewing wood.

"Wild horses might go 20 miles to eat a certain rock dust or clay deposit. The diatomaceous earth falls into that category. The biggest thing we use it for is as a source of organic silica in a free choice mineral program, which the horse can use to build bone, teeth and connective tissue." She says that silica in the diet is important for the strength of body cells, helping maintain tissue integrity and elasticity.


She says, "The other thing we use it for is as a natural pesticide. A lot of organic growers use it as a spray on fruit trees, to inhibit insects. We use it as an insecticide in our feed mills, because we don't want pesticide chemicals (such as malathion or methyl mercury) through the mill, coming into contact with our feed or supplements. So we run diatomaceous earth through to mill to help get rid of grain moth and weevil."
Pesticides are a "huge source of feed contamination that a lot of people don't even consider. A feed that claims to be naturally preserved and chemical free, but yet is being produced by a mill that is fumigated with chemicals, may still create problems, so we use this as a natural pesticide." Some people also use diatomaceous earth for insect control around their houses or gardens to get rid of fire ants and spiders. It is also used as a feed-through for fly control; since some of it is not digested, it passes on through with the manure, where it inhibits the fly larvae after flies lay their eggs in the manure.

"Animals that are nutritionally balanced usually don't have as many flies to begin with," says Sinner. "We use flies as a judge as to how clean a horse is, and how well the feed program is working. Animals that are fed a cleaner diet and are really healthy, actually have a vibration that tends to repel the insects. When you think about it, flies go to garbage. They go to dead things." Fly maggots are nature's way to clean up dead bodies.
"They are attracted to the less healthy horse. If you have a horse that is attracting more flies than its herdmate, you should suspect a problem. A calcium deficiency can be a part of that - or if the horse is nutritionally out of balance or toxic. Flies will tend to gather on areas of the horse where the energy is more blocked. Horses getting too much protein will have runny eyes, and more face flies. You can actually use flies as a diagnostic tool," she says.

She feels that the healthier and cleaner a horse is, the less flies it will attract; the flies generally move on to another horse - to easier pickings - if they can. "The better the animals are in digesting their food, the less protein matter they leave in their manure," says Sinner. "That's what attracts the flies." Many people feed more protein than their horses need. "We have a rule of thumb that mammals don't need any more protein than what their mothers' milk contains, and mares' milk is about 12 percent. As an adult, a horse doesn't even need that much."

Diatomaceous earth is not a panacea, she says, "but it has a place in a feeding or management program. People have to make their own judgment as to whether it is an adequate form of parasite control. It can enhance a control program - used in conjunction with other methods - and you may not have to rely so heavily on other measures."

She says, "We make a big distinction between deworming and parasite control. Diatomaceous earth is not really a dewormer, but
I consider it to be a form of parasite control. If the parasites get out of control, then you need a dewormer. I see people that throw the baby out with the bath water, saying they don't want to use toxic chemical wormers, so they quit deworming their horses altogether, and end up in trouble. It's important to make this distinction."

Diatomaceous earth is also used by some people as an external pour-on for cattle. "It wouldn't be very long-lasting, but might inhibit the insects that walk through it," she says. "Flies and lice are opportunistic, attracted to an animal that is debilitated or has a poor immune system. When you consider internal parasites, they are designed by the grand scheme of things to help speed the demise of the weak and unhealthy ones. That's what people don't realize when they get on the treadmill of over-worming (and over- vaccinating); the horse actually ends up with less defenses. Overuse of these things can damage the immune system rather than making it stronger, by not letting the body build its own defense, and by stressing all the organs of elimination - liver, kidneys, lungs and skin. Each horse is an individual, and you should work with your veterinarian to design a program for each one."

She says that the parasite infested horses are in many cases the ones that are dewormed the most frequently; they can't build their own antibodies and are less able to fend off the parasites as time goes on. The retired horse out in the field living a life of semi-neglect may actually be doing better than the pampered horse in the barn. The more natural the conditions you can keep horses in, the better off they are, in most cases. "A balanced mineral program including free choice minerals will honor horses’ basic instincts," Sinner says.

For more information:
Judy Sinner
Dynamite Specialty Products

About the author:
Heather Smith Thomas is the author of thirteen books including “Storey's Guide to Raising Horses”, and her latest, “Storey's Guide to Training Horses”. She has written more than 6,000 articles for hundreds of publications, including “Chronicle of the Horse”, “Equus”, “Quarter Horse Journal”, “Horse & Rider”, and “Horse Illustrated”. At their cattle ranch in rural Idaho, Heather and her husband have bred, raised and trained horses for nearly 40 years.