(DE) Diatomaceous Earth and Bison

Buffalo Wallows

The Real Dirt on Diatomaceous Earth Used For Worming Bison


Buffalo Wallow with (DE) Diatomaceous Earth 


I’ve been using DE for well over 20 years and taking pictures of the bison’s interaction for only about the last five years. I was surprised when I started posting the images and how many people didn’t know what it was.  I started using it for insect control and as a dewormer for my horses. Then expanded to pest control for the dogs, garden, and yard during the warmer active months. It remains effective as long as it’s kept dry.

I visited a large horse ranch in southern Texas to pick out one of their foals. I was almost sickened by the number of flies the foals had to deal with. They were covered and how miserable they must have been. This ranch was huge so to spray would have cost a fortune and been pointless. So at the end of my visit, I asked them if they ever tried D.E., Of course, they never heard of it. Within a week, they called me thanking me over and over, in fact, one of the owners was now taking it himself (human grade) and commented how much better he felt. While I have never tried it internally, I do highly recommend it for pest control. 

Truck DE Roll Truck after DE roll


What Is Diatomaceous Earth?

It’s useful, but what the heck is it, exactly? The short answer is fossils! Diatomaceous earth (pronounced “dia-toMAY-shus” earth) is ground fossilized remains of a type of phytoplankton called diatoms, which have existed on Earth for millions of years. Of course, to look at diatomaceous earth, it doesn’t look like fossils — it is more of an off-white powder that looks similar to talc and has no odor.


Diatomaceous earth is a naturally occurring sand extracted from the earth.

It consists of microscopic skeletons of algae — known as diatoms — that have fossilized over millions of years (1).

There are two main types of diatomaceous earth: food grade, which is suitable for consumption, and filter grade, which is inedible but has many industrial uses.

The diatoms in diatomaceous earth are largely made up of a chemical compound called silica.

Silica is commonly found in nature as a component of everything from sand and rocks to plants and humans. However, diatomaceous earth is a concentrated source of silica, which makes it unique (2).

Commercially available diatomaceous earth is said to contain 80–90% silica, several other trace minerals, and small amounts of iron oxide (rust) (1).

Silica exists in two main forms, crystalline and amorphous (non-crystalline).

The sharp crystalline form looks like glass under a microscope. It has properties that make it desirable for numerous industrial applications.

The two main types of diatomaceous earth vary in their concentrations of crystalline silica:Sacked DE

    • Food Grade: This type contains 0.5–2% crystalline silica and is used as an insecticide and an anti-caking agent in the agricultural and food industries. It is approved for use by the EPA, USDA, and FDA . 573.340 Diatomaceous earth. (a) Identity. The additive consists of siliceous skeletal material derived
      from various species of diatoms. (b) Specifications. The additive shall conform to the following specifications: Lead, not more than 15 parts per million.

Arsenic (as As), not more than 20 parts per million Fluorine, not more than 600 parts per million. (c) Uses. It is used or intended for use as an inert carrier or anticaking agent in animal feeds in an amount not to exceed 2 percent by weight of the total ration. (govinfo.gov)

  • DO NOT USE THIS: Filter Grade: Also known as non-food-grade, this type contains upwards of 60% crystalline silica. It is toxic to mammals but has many industrial uses, including water filtration and dynamite production.

    Diatomaceous earth.com: Diatomaceous Earth: Bison Feed Additive “is an excellent feed additive for your animals. Ranchers and pet owners alike have many stories of the benefits of adding diatomaceous earth to animal feed. Used as a feed additive, DE can promote intestinal and digestive health, healthier coats, and much more.”

  • Feed Ratio: 2% of their feed intake. That means for 10 lbs of feed, you will need to add roughly 3 oz. of DE.

When I was feeding it to my horses, I added about a 1/2 Cup to their grain ration per/hd per/day. 


Diatomaceous Earth as an Insecticide

Food-grade diatomaceous earth is often used as an insecticide.

(DE) Diatomaceous Earth and Bison
A scoop of DE over cubes, keeps the insects out of my feed.

When it comes in contact with an insect, the silica removes the waxy outer coating from the insect’s exoskeleton.

Without this coating, the insect cannot retain water and dies of dehydration (6).

Some farmers believe that adding diatomaceous earth to livestock feed kills internal worms and parasites through similar mechanisms, but this use remains unproven (7).

I used to feed this to my horses as an alternate dewormer. It did work for certain types and I saw the evidence in the fecal matter the next day. But I never relied on it solely for a dewormer. I was just reading yesterday from a Vet MD, about using it for deworming dogs. (8)

Years ago I read from the Canadian Bison Association (2014) about DE as a bison wormer. Their findings were that while some ranchers claim to have success with it, the science could not back up their results.  Scientific evidence suggests that it is best used for insects and external parasites.

I wished it was effective as a dewormer for bison, it would be so much easier for everyone to care for their bison. Just add it to their feed, so simple right?  I read that they don’t build up a resistance to it like other dewormers. But, I love how effective it is for the biting flies. After living on a feedlot, flies just disgust me. So whatever I can do to relieve my stock from the pest, I will try. 

I use a regular-sized feed scoop of DE in the container I keep my feed cubes in, just to keep the bugs and out of it and the bison readily consume the product without hesitation. 


Southern Plains Bison Pointers July 2019 – Fly Control   https://allaboutbison.com/fly-control-in-bison


This works and they love it.

Cow and calves rolling in DE
New Calf Trying to Roll
Truck Face Plant
Face Plant
DE Hang Out
During the warmer times, the bison will often just lay around in the DE







This heifer calf was not born here and was not raised around DE, nor did she socialize with the existing bison herd. She is one of 3 bottle babies I raised for a bison ranch in West Texas. This was her first experience with DE.

Pistol and 1st DE

Truck (bull) loves it so much, I have to be careful around him. I try to put it out when he is not around because he will run to me trying to be the first at the DE. On this occasion, I thought I had time to get out before he could reach me. So close……I was only able to dump part of the bag and l like to make at least two piles because he will just lay in one pile and not give the others their time to roll.  He would have waited all day, I finally had to remove the bag and wait for another chance.

Truck waiting for DE


Where to find Diatomaceous Earth?

I’ve always been able to pick it up at our local feed store, in all the places I’ve lived. So check with your local store and if they don’t have it, I’m sure they can get it. I used to pay about 20 bucks for a 50lb sack, with the prices going up all the time, my latest pick-up was about 27$. Fairly cheap for what I and the buffalo, get in return. (unless it rains)