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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

Is Your Dog Eating Grass, Vomiting, and Getting Sick?

Updated: April 13th, 2021


Is your dog eating grass, vomiting and getting sick? Could be the pesticides and herbicides — war weapons — we use on our green spaces.

Is your dog eating grass, vomiting, and getting sick?

Could be because of your walk this morning.

You walk out your door and the sun is shining beautifully on the well-manicured lawns surrounding your home. You’re getting ready to take your dog for his morning walk. During the walk, he enjoys rolling in the grass. He rolls as if he’s never seen grass before, and he’s never going to see it again. You return home, and oops, he’s digging up your garden. He even eats some grass. This scenario appears to be perfect (minus the fact that our dog has now deconstructed your garden)– but there’s danger lurking behind the scenes.

If you see your dog eating grass, vomiting, and getting sick, it could be because of the chemicals used.

How did that lawn become so beautiful, anyway?

When we go out into the wilderness (this is beautiful, too), do we see the unstructured, unorganized weeds surrounding us as we walk through the mesmerizing forest? Yes, of course, we do.

Why don’t we see weeds in our lawn?

The answer… pesticides. Pesticides and herbicides are used on many lawns to reduce or eliminate the weed populations to make our yard more visually appealing. To make our yard look prettier.

Even though the pesticides we use outside make our yard more appealing, they aren’t good for our dogs (or us!).

To make matters worse, pesticides can be found not only in your own backyard or in your neighbor’s yard but can also be found in parks, gardens and even those little pieces of grass next to the sidewalk as you’re walking through town.

When pesticides that contain glyphosate or 2-4 D are applied in your yard to make the lawn more appealing, they don’t just stay on the grass. The chemical is on the grass but has also been detected in the air, the soil, and in the foods, our dogs (and we) eat.

Glyphosate Research Goes Unpublished

There is a chemical in weed-killers known as glyphosate, and it’s extremely dangerous to dogs, and us.

The way glyphosate, the primary ingredient in pesticides like Round-Up, kills plants is by taking away a plant’s ability to use a certain protein (known as an enzyme), which blocks them from eating. The plant basically starves to death.

If you research the health effects of glyphosate, you will find information … but it will be scattered. And, you’ll have to put the pieces of the puzzle together for yourself to get a full picture.

You will notice hundreds of lawsuits, which have not yet been settled. Important research went unpublished for some time, but some countries have already started banning glyphosate or enforcing stricter regulations.

Sri Lanka has banned the use of glyphosate completely. Canada has started to enforce new regulations. Mexico and the Netherlands have already taken action to enforce new regulations.

Agent Orange in Our Pesticides

You may have also heard of an herbicide known as ‘Agent Orange’ that was used in World War II and in the Vietnam War.

Planes dropped Agent Orange over the forests, to kill the trees and underbrush, so the enemy couldn’t take cover and were easier to bomb. A quick search will give you plenty of horror stories about the damage to health it caused for both sides in those conflicts.

Agent Orange contains a dangerous chemical called 2,4-dichlorophenoxyacetic acid- or 2,4-D, which Dr. Dressler writes about in The Dog Cancer Survival Guide starting on page 79.

2,4-D takes pesticides one step further as it’s even more toxic than glyphosate. 2,4-D has also been shown to cause adverse health effects including liver disease, lowered sperm counts and non-Hodgkin lymphoma in humans. And recently, 2,4-D began being sprayed on crops to kill the weeds once they became resistant to glyphosate.

New pesticides are also combining glyphosate and 2,4-D to make an extremely powerful herbicide. Since so many weeds are now resistant to glyphosate, a different weed killer has been deemed necessary.

While this may sound great outside of the box, the inside of the box isn’t so pretty. The herbicide may get rid of weeds for a while, but eventually, the weeds will become resistant to this weed-killer too. And, all we’re left with are damaging health effects for us and our dogs.

Pesticides and Your Dog (And Us!)

Even if you don’t use pesticides, your neighbors (or the local government) might.

Your dog loves to walk through the park, roll in the grass, and you may even notice him eating the grass. If that grass has been sprayed with glyphosate, or worse, glyphosate and 2,4-D together, that means your dog is walking through it, rolling in it, eating it, and breathing it.

When glyphosate is consumed, it can cause a range of serious effects in dogs including:

  • Diarrhea
  • Vomiting
  • Cardiac arrest
  • Anorexia

If you see these symptoms after your dog eats grass, make sure to mention that fact to your veterinarian.

There still isn’t an abundant amount of research about how pesticides affect our dogs specifically. But, there has been some research published about pesticides and humans.

Dogs are mammals like us. And they’re often much smaller. So, you can only imagine what damage pesticides do to their little bodies.

According to the Center for Disease Control and Prevention, when exposed to 2,4-D in the short-term, you might become weak and lethargic, go into a kind of stupor, have muscle twitches, and/or experience convulsions.

Those who are exposed to 2,4-D for a long period of time might see damage to all of their organs. Long-term exposure to 2,4-D may result in cardiovascular disease, kidney disease, liver disease, skin disease and/or neuropathy.

The signs might not be immediate, the symptoms could be seen years after exposure.

Even the pesticide label warns us (as humans) not to get any on our skin, or in our eyes, and encourages the use of gloves while using it.

Which sort of begs the question: given all of this, why is it okay for us to still use pesticides that contain glyphosate or 2,4-D? And, how is a new strain of chemicals being released that are equally or more dangerous to life on Earth?

The Link to Cancer

The World Health Organization, commonly known as WHO, published an article covering the high possibility that glyphosate, found in pesticides, causes cancer in people and animals.

WHO makes these connections because research shows glyphosate use might cause changes in a mammal’s DNA and damage to a mammal’s cells.

A few other studies outlined a link between pesticides containing glyphosate and rare pancreatic and kidney cancers in animals.

Dog Cancer and Pesticide Use

Another study, published in Environmental Health, outlined dogs in relation to cancer and pesticide use.

In the study, 263 dogs were identified with malignant lymphoma. Another 240 dogs with benign tumors and 230 undergoing surgery not related to cancer were included, too.

The researchers requested the dog guardians fill out a questionnaire which asked about their environment, their medical history, and which pesticides or insecticides were used in and around the home.

  • Dogs with malignant lymphoma were up to 70% more likely to live in homes where pesticides were used.
  • Dogs who had significant malignant lymphomas were 170% more likely to live in homes where insecticides were used.

Reduce Your Exposure and Increase Your Knowledge

Even though there isn’t much we can do about our neighbors or local governments using pesticides and herbicides, there are steps we can take to reduce our dog’s exposure to them.

  • Don’t use them in your own yard. If you do use pesticides and herbicides, look for formulas that don’t contain glyphosate or 2,4-D.
  • Do your own research!
  • Join an organic gardening/farming association near you
  • Educate others on the dangers of pesticides and herbicides
  • Wash any fruits and vegetables you come into contact with, especially before eating
  • Learn which fruits and vegetables are on the Dirty Dozen and Clean Fifteen lists

There aren’t any pesticides that are ‘truly’ safe. Because, if we think about it, nature didn’t create the pesticides we’re using. We’re killing our plants with toxic chemicals and the toxins don’t end at the plants. They carry on to be toxic to us and our dogs.


Learn More About Pesticides

To read more about the dangers of pesticides for your dog, take a look at the list of resources below.

5 Ways to Get Pesticides Out of Your Dog, Dogs Naturally Magazine

Agent Orange, The History Channel

Cancer Agency Left in the Dark Over Glyphosate Evidence, Reuters

Carcinogenicity of Tetrachlorvinphos, Parathion, Melathion, Diazinon and Glyphosate, The Lancet

Enlist Duo Herbicide, Enlist Weed Control System

Heavy Use of Herbicide Roundup Linked to Health Dangers, U.S. Study, Reuters

Herbicide Glyphosate Found in Pet Foods, Truth About Pet Food

Household Chemical Exposures and the Risk of Canine Malignant Lymphoma, a Model for Human’s Non-Hodgkins Lymphoma, PubMed

How Dangerous is Pesticide Drift?, The Scientific American

Lawn Chemicals and Cancer in Dogs, Dogs Naturally Magazine

Meet the New Monsanto: Dow Chemical… and Their New ‘Agent Orange’ Crops, The Huffington Post

Monsanto’s Roundup Faces European Politics and U.S. Lawsuits, New York Times

Nasal Cancer, in Memory of Max, The Police Dog, The Dog Cancer Blog

Occupational Health Guideline for 2,4-D, Center for Disease Control and Prevention

Overview of Herbicide Poisoning, Merck Veterinary Manual

Patients: Roundup Gave Us Cancer as EPA Official Helped the Company, CNN

Summer Dangers for Dogs with Cancer, Dog Cancer Blog

Questions About EPA- Monsanto Collusion Raised in Cancer Lawsuits, Huffington Post

What Do We Really Know About Roundup Weed Killer?, National Geographic

Dog Cancer Blog: Herbicides, Pesticides, and Other Chemicals

W.H.O. Report Links Ingredient in Round-Up to Cancer, The New York Times

Leave a Comment

  1. Mary Alice Andrys on July 11, 2020 at 3:31 pm

    In 2019 my 8 1/2 year old female black lab was exposed to Scott’s Weed and Feed that was applied wet. A few days later she was let out the grass was dry but the chemical was not watered in 24-48 hrs. as directed. She had run through it a few times and may have eaten some grass that had this on it. Careless I know. She did not get sick vomit or have diarrhea. 4 1/2 months later she started to have seizures and had a mri that said she had a Oligodendroglioma brain tumor. She had a tumor removal but it was high grade and came back. She is no longer with me. I am having a hard time thinking this was a coincidence. I believe these chemicals and those containing 2,4D are deadly. They should be illegal to have on the market. I would like to hear your thoughts. Thank you

  2. Lin on June 2, 2020 at 11:44 am

    My dog has TCC and being treated with Yunnan Baiyao Blue box for bleeding.
    I ordered some more and it is a green box. Is that the same thing?
    Should I switch????

    • Molly Jacobson on June 2, 2020 at 12:02 pm

      Hello Lin, Yunnan Baiyao is not a brand, it’s an herbal formula — so it is manufactured by several different companies. It’s possible that you just bought from a different company. If you have any question about whether you are using the right herbal formula for your dog’s case, please consult your veterinarian!

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