Diatomaceous Earth: A Natural Flea Remedy?

Bronwen Mason lives in beautiful Edmonton, AB, where enjoying the great outdoors is practically a provincial pastime. Unfortunately, that sometimes comes with a cost for the camping enthusiast—the risk of lice, ticks, and fleas. “We get these over the spring to fall months,” says Mason.

But it was at the groomer’s where her 17-year-old Yorkshire Terrier rescue, Annie, picked up lice.

Chemical flea treatments didn’t work for the family in the past. “I had a horrible anaphylaxis to flea treatment,” says Mason. “Also, Annie had thrown up for three days after our last flea application. Since they all have similar ingredients, we decided to try a natural route, with the caveat that if we didn't see results, we'd go back to the vet for a treatment.”

Mason bought a two-pound bag of food-grade diatomaceous earth (DE), and went online for instructions.

“Basically, dust the dog with the DE, watch for not getting it in eyes or noses as it cannot be inhaled, then comb out any lice and eggs that we could find,” says Bronwen. “It's for sure a higher maintenance method. It took me about a week of this to get results, but it was worth it. I didn't end up having a reaction—my issue with the treatments according to my doc and allergist is that I'm chemically sensitive to them—and Annie didn't get sick.”

Touted as natural and chemical free, diatomaceous earth is made from crushed fossils of diatoms, a type of single-celled marine life. It is readily available at health food stores or online in the form of white powder, and is used for many things, including filtration, as an abrasive in polish, as cat litter and as a mechanical insecticide used to control household and garden pests, including the ones that bother dogs the most— ticks, fleas, lice, and mites.

When the diatoms in the diatomaceous earth come into

contact with the insects, they scrape away the protective shell, causing them injury and to die, without the use of poison.

“I would totally recommend it for anyone who is looking for an alternative to the chemical treatments,” says Mason. “As a side bonus, I was able to dust my other dog, their bedding, my couch, etc. So, it works as a treatment on places where you normally wouldn't want to spread (chemical) treatment.”

Mason is just one of a number of pet owners who have tried diatomaceous earth for their pets.

Debbie Matlow, of Huntington Beach, CA, found DE through online research on alternative flea treatments. She purchases it from a tack and feed store in nearby Costa Mesa, and sprinkles it wherever her dogs—a 14-year-old Pug named Giorgio Armani and a two-year-old Bulldog named Bizzie, go—the couch, carpet, bedding, and crates.

“I usually leave it in the carpet for a day, and then vacuum,” says Matlow. “I leave it between and under the couch cushions for a few days also, then vacuum… I also put it on my dogs, I sprinkle it and rub it into their coats, on their backs and rear ends. I'm very satisfied with the results, as I do not like to give my dogs chemicals. Flea meds are like eating insecticides and the topicals are just as bad. I've read so many horror stories about both.”

When Emma, a Maltese/Poodle mix with congenital kidney disease received the same fatal diagnosis from almost a dozen veterinarians, her pet parent, Evrim Ertemur, decided to “ditch all the chemicals and pursue an organic, natural way for everything”—including flea medication—and never looked back.

“The last time I gave her flea medication, she threw up,” says Ertemur, who lives in Newark, CA. “I think [DE] is very effective.”

In addition to sprinkling it on her dog, Ertemur also uses DE in her garden to get rid of snails and fleas. DE labels have also stated that the product kills other undesirable insects, including cockroaches, beetles, earwigs, silverfish, spiders, and termites, while being safe for birds and pets.

Dr. Michael Goldberg, who specializes in veterinary homeopathy and veterinary chiropractic medicine at Harpaws Holistic Veterinary Services, Inc. in Whistler, B.C. has had clients over the years use human grade DE on both pets and the environment, as well as giving it to their dogs internally, to rid of internal parasites. One pet owner who has used food grade DE internally is Jessica Santos, of Albuquerque, NM, who has added it to her dogs’ food, for treatment for intestinal worms. Containing minerals including calcium, copper, iron, magnesium, phosphorus, potassium, sodium, and zinc, DE has also been used as a nutritional supplement for dogs and people, and is said to help with hair, skin, and nail health, as well as increasing energy.

“There is a published agricultural study on [DE’s] effects on insects which are more favourable than doing no treatment,” says Dr. Goldberg, who refers to a paper by Thomas E. Ross, titled “Diatomaceous earth as a possible alternative to chemical insecticides.” The paper states that as chemical insecticides are known to be often hazardous to many life forms within the natural environment, less potent insecticides should be explored. It also examines diatomaceous earth as a pest control agent.

“As it is a natural product, I feel if they are careful with it

(re: inhalation), it’s always worth it to try and see if they can control the situation prior to attempting other (chemical) methods that may in the long run have unknown effects on both pet and environment,” says Dr. Goldberg, who is a member of the Canadian Veterinary Medical Association, Society of Veterinarians of B.C., Academy of Veterinary Homeopathy, International Association of Veterinary Homeopathy, and the American Holistic Veterinary Medical Association.

However, as with many alternative treatments, the jury is still out on whether diatomaceous earth really works.

Dr. Katherine Kramer, medical director for VCA-Canada Vancouver Animal Wellness Hospital, a small animal integrative hospital in Vancouver, B.C., says she “would not recommend diatomaceous earth for any canine health condition.

“The use of DE is well known,” says Dr. Kramer. “It has been touted as a natural insecticide, dewormer, detoxifying agent, nutritional supplement. One particular website lists 31 health benefits of DE for people, ranging from supporting the immune system, decreasing headaches, and decreasing the risk of heart disease, dementia, and Alzheimer's disease,” she says. “The use of natural remedies, including DE, are typically growing in popularity as we are all looking for safe, natural, and inexpensive products to use instead of pharmaceuticals. It is extremely important to remember that just because a product is 'natural' that doesn't mean that it is safe or effective,” she says.

Although several of her clients over the years have used DE for flea prevention for their dogs, Dr. Kramer says that she “would not recommend diatomaceous earth as a safe, alternative to medicine.

“The scientific evidence remains slim,” says Dr. Kramer. “Studies have shown some efficacy against fleas, mites, and some intestinal parasites (mostly in chickens) but the risk of causing lung damage is incredibly high. Most DE is composed of silicon dioxide that comes from a sedimentary mineral composed of the fossilized remains of diatoms (oceanic microorganisms).” Silicon dioxide is an abrasive substance of sharp microparticles, making it potentially harmful when inhaled, she says.

On this point, Dr. Goldberg agrees. “I do forewarn the clients that it can be a respiratory irritant to both them and their pets, so avoid overuse and breathing it in,” he says.

Victoria Marchlinski was concerned about the risk to her lungs, and for that reason, she wore a mask when using DE on her Shih Tzus for flea control a number of years ago. When she did use DE, she found it effective—“done consistently, you will rid them of fleas,” says the Saddle Brook, N.J. resident.

Dr. Kramer reminds pet owners that it’s buyer beware. “Anytime you are considering a supplement for your dog, please consult your veterinarian,” she says.

“In my practice, we use many natural supplements, such as herbs, turmeric, glucosamine, green-lipped mussels, milk thistle, and hemp, that are safe and effective. However, even 'safe' supplements can interact with medications and have side effects. Unfortunately, there are a lot of supplements on the market that are neither safe nor effective.” She suggests “diluted essential oils, sprayed topically” as an alternative for flea prevention.

But in the meantime, many dog owners have done their own extensive research and are satisfied to find an alternative to chemicals. “I was very happy to find a solution that worked for our unique situation,” says Mason. 

“It's for sure a higher maintenance method. It took me about a week of this to get results, but it was worth it.”