As a dedicated content creator for pets.edu.vn and a pet expert, I understand your concerns about the products you use around your furry companions. You might diligently avoid spraying Roundup weed killer in your own garden, but the reality is, Roundup is pervasive. It can be found in unexpected places – potentially in your dog’s food, their water, and certainly on the ground they walk on every day. This constant exposure raises a critical question for every pet owner: is Roundup weed killer safe for pets?
Mounting research indicates a concerning answer: it’s not.
Understanding Roundup and Glyphosate
Roundup is a widely recognized brand of herbicide, designed to eliminate unwanted plants. It’s readily available for home use in convenient bottles, and its application extends far beyond residential gardens. Farmers rely on it extensively in agriculture, and even cities utilize it for public weed control. The primary active ingredient in Roundup is glyphosate. However, the formula also includes other potentially harmful components, such as surfactants. These surfactants enhance glyphosate’s effectiveness by helping it adhere to plant surfaces.
Glyphosate has become one of the most commonly used herbicides across the United States. Its applications are vast, ranging from large-scale agriculture to your neighbor’s carefully manicured lawn, forestry management, and even controlling weeds in aquatic environments.
Alt text: Roundup weed killer bottle and gardening gloves on lawn, illustrating potential pet exposure to herbicide.
How Glyphosate Impacts Plants and Potentially Pets
Glyphosate is classified as a non-selective herbicide. This means it has a broad-spectrum effect, killing almost all types of plants it comes into contact with. It achieves this by disrupting a crucial enzyme pathway known as the Shikimate pathway. This pathway is essential for plants, algae, fungi, and bacteria to produce vital amino acids, including tryptophan, tyrosine, and phenylalanine.
Alarmingly, studies suggest dogs can harbor up to 30 times more glyphosate in their systems than humans.
Beyond blocking amino acid production, glyphosate also acts as a chelator. This means it interferes with a plant’s ability to absorb essential nutrients like calcium, magnesium, manganese, zinc, iron, copper, nickel, cobalt, boron, molybdenum, selenium, and potassium. In essence, glyphosate undermines a plant’s health by depriving it of nutrients and weakening its natural defenses – much like how AIDS compromises the immune system.
And this is where the concern for our pets arises: glyphosate’s mechanism of action in plants raises significant questions about its potential impact on animal health, particularly on dogs who are frequently exposed.
The Pervasiveness of Roundup and Glyphosate Exposure for Dogs
Research highlights the increasing presence of glyphosate in our environment and in living organisms. A study comparing glyphosate levels in Californians between 1993-1996 and 2014-2016 revealed a disturbing trend: both the number of people testing positive for glyphosate and the concentration of glyphosate in their systems had increased significantly.
Data from a lab at the University of California San Francisco indicates that a staggering 93% of humans have detectable levels of glyphosate in their urine. The average concentration found was 3.096 parts per billion (PPB), with children exhibiting the highest levels. Geographically, individuals in the Midwest and Western regions showed the highest exposure. The elevated levels in children are so concerning that US legislation has been proposed to limit glyphosate exposure in this vulnerable population.
This widespread human exposure is alarming in itself. Adding to the concern, a recent study linked glyphosate exposure to a 41% increased risk of cancer in humans. However, the situation appears even more critical for our canine companions. A pilot study by HRI Labs discovered that glyphosate levels in dogs are, on average, 30 times higher than those found in humans.
This stark difference in exposure levels begs the question: what are the potential health consequences for dogs facing such high levels of glyphosate in their daily lives?
Roundup, Lawn Chemicals, and the Cancer Link in Dogs
Canine cancer is a devastating reality for many dog owners, affecting roughly half of all dogs today, and alarmingly, the incidence is on the rise. Exposure to glyphosate and lawn chemicals could be a significant contributing factor to this trend.
A comprehensive 6-year study conducted at Tufts University established a link between lawn chemical exposure and a 70% increase in the risk of lymphoma in dogs.
A growing body of scientific literature points to Roundup as an endocrine disruptor, a destroyer of beneficial gut bacteria, and a substance capable of damaging DNA.
Further research in a 2013 study revealed that lawn chemicals also elevate the risk of bladder cancer in dogs. Notably, this study also detected glyphosate in the urine of dogs living in homes where herbicides were not directly applied to their own lawns, highlighting the widespread environmental presence of this chemical.
The potential cancer-causing properties of glyphosate have also been recognized by international health organizations. The World Health Organization (WHO) has classified glyphosate as a probable carcinogen based on a unanimous vote by cancer research experts. In 2017, California officially listed glyphosate as a known human carcinogen under Proposition 65 law. This contrasts sharply with the more lenient stance taken by the US government.
The EPA maintains that glyphosate is not harmful when used as directed, although this position has faced increasing scrutiny. In 2022, courts even ordered the EPA to re-evaluate its stance on glyphosate’s safety. Adding to the controversy, former US FDA Commissioner Margaret Hamberg, in an attempt to downplay the cancer link, stated:
“Sure, you could say that glyphosate causes cancer, of course it does … but only when swallowed in small amounts over a long period of time.”
This statement is particularly concerning because it describes the exact nature of widespread glyphosate exposure – chronic, low-dose exposure for virtually everyone through food, water, and the environment.
Alt text: Dog resting on a green lawn, symbolizing potential exposure to Roundup and lawn chemicals in domestic environments.
The Verdict: Is Roundup Safe for Dogs?
Based on the accumulating scientific evidence, the answer to the question “Is Roundup safe for dogs?” is a resounding no. Over the past two decades, research has consistently documented the adverse health consequences associated with Roundup and glyphosate exposure. Studies have shown a clear correlation between higher glyphosate levels and poorer health outcomes in both humans and animals.
The scientific consensus is growing: Roundup acts as an endocrine disruptor, disrupts the delicate balance of beneficial gut bacteria, and can cause damage to DNA, all of which can have serious implications for your dog’s health and well-being.
Glyphosate Exposure: A Range of Associated Health Issues
The range of health problems linked to glyphosate exposure is extensive and alarming, affecting multiple systems within the body:
Alzheimer’s Disease: Glyphosate has been shown to induce oxidative stress, a key characteristic observed in Alzheimer’s patients, suggesting a potential link between glyphosate and neurodegenerative diseases.
Autism: Researchers are exploring a possible connection between glyphosate exposure and autism, with gut dysbiosis, an imbalance in gut bacteria caused by glyphosate, as a potential underlying mechanism.
Birth Defects: Glyphosate can interfere with vitamin A pathways, which are critical for normal fetal development, raising concerns about its potential to cause birth defects.
Brain Cancer: Studies indicate an increased risk of brain cancer with glyphosate exposure, highlighting its potential carcinogenic effects on neural tissues.
Cancer: Areas with high Roundup usage have reported significantly elevated cancer rates. A study published in the Environmental Research Journal found that dogs living in homes where pesticides were used had a 70% higher risk of developing malignant lymphoma.
Heart Disease: Disruption of amino acid biosynthesis, a direct effect of glyphosate, has been linked to the development of heart disease.
Liver Disease: Even low doses of Roundup have been shown to disrupt liver cell function, indicating potential hepatotoxicity.
Kidney Disease: Scientists have concluded that the rise in kidney failure among agricultural workers in regions like Central America, Sri Lanka, and India is likely linked to glyphosate exposure.
Reproductive Problems: Glyphosate can negatively impact reproductive health, affecting sperm production and potentially decreasing testosterone levels during puberty.
Leaky Gut: Glyphosate can induce severe tryptophan deficiency, leading to inflammatory bowel disease and impaired nutrient absorption, contributing to leaky gut syndrome.
Roundup’s Ubiquitous Presence: Exposure Beyond the Lawn
It’s crucial to understand that your dog’s exposure to Roundup isn’t limited to walks on treated lawns. Dogs are exposed to glyphosate daily through multiple pathways: their food, the air they breathe, and their drinking water.
The introduction of genetically modified (GMO) foods has dramatically increased Roundup’s presence in our food chain and environment. Global glyphosate use is estimated at a staggering 20 billion pounds annually, a 15-fold increase since the introduction of Roundup Ready crops in 1996. Nearly 75% of all glyphosate used on crops has been applied in just the last decade.
The first Roundup Ready crops were cotton, corn, and soybeans. Since 1996, the list of genetically engineered foods has expanded significantly. The top four GMO crops are:
- Corn: 88% of corn grown in the US is GMO or Roundup Ready.
- Soy: 93% of soy is GMO. Soy derivatives like lecithin, tocopherols (vitamin E supplement), oils, and proteins are common ingredients in pet food.
- Cottonseed: 94% is GMO and used in vegetable oils.
- Alfalfa: Nearly all alfalfa in the US is GMO. Alfalfa is a common component of animal feed, leading to glyphosate accumulation in meat products.
The list of GMO foods continues to grow, including apples, potatoes, squash, rice, plums, flax, tomatoes, beets, and more. Each year, more and more foods are becoming Roundup Ready. It’s estimated that nearly 70% of processed human foods contain GMO ingredients, and the percentage is likely even higher in pet foods.
However, glyphosate contamination extends beyond GMO crops.
Roundup is frequently used as a desiccant on non-GMO crops like wheat, barley, oats, beans, peas, flax, rye, buckwheat, millet, beets, potatoes, and other crops just before harvest. This pre-harvest application of Roundup is used to dry out crops and accelerate harvesting.
Even organically labeled crops may be subjected to Roundup desiccation. Therefore, even if a food label claims “non-GMO” or “organic,” it may still contain glyphosate residues. This pre-harvest desiccation practice is a likely contributor to the doubling of glyphosate residues found in human urine in recent years.
Roundup Contamination in Pet Foods
Independent research has confirmed the presence of glyphosate in pet foods. Glyphosate researchers Anthony Samsel and Stephanie Seneff tested a small sample of various pet foods and found glyphosate in every single sample.
Regarding glyphosate levels in dog food, kibble dog food was found to contain over 100 times higher glyphosate levels compared to commercial raw dog food options.
However, even raw feeding, whether homemade or pre-made, doesn’t completely eliminate glyphosate exposure. Consider the sources of meat and bones in raw diets. Conventional meat sources often come from animals fed corn and soy-based diets, which are likely to be GMO and treated with Roundup. Even grass-fed animals may graze in fields previously treated with glyphosate.
If you are not feeding certified organic, grass-fed meats and bones, your dog is likely being exposed to glyphosate through their diet. Glyphosate’s mechanism of mimicking glycine allows it to replace this amino acid in the body. Furthermore, glyphosate’s ability to bind with calcium facilitates its absorption and accumulation in bones.
The EPA’s tolerance level for glyphosate in meat and meat byproducts is 5 ppm (parts per million). Tests by HRI Labs have shown that most commercial raw pet foods contain glyphosate at this level, but kibble dog foods exhibit dramatically higher concentrations, ranging from 200 to 660 ppm.
Opting for a raw diet, particularly incorporating grass-fed bones and meat when possible, can significantly reduce your dog’s glyphosate exposure compared to kibble-based diets.
Roundup’s Impact on the Microbiome: A Hidden Danger
Recall the Shikimate pathway disrupted by glyphosate in plants. While dogs don’t directly rely on this pathway for energy production, the trillions of bacteria residing in their microbiome do. Your dog’s immune system is intricately linked to this vast community of microorganisms living on their skin, in their digestive tract, and throughout their body. This microbial ecosystem, known as the microbiome, is so vital to health that it even communicates directly with the brain.
Glyphosate wreaks havoc on this beneficial bacteria by disabling their Shikimate pathway. Healthy intestinal bacteria are essential for producing vitamins, short-chain fatty acids, and for outcompeting harmful bacteria and viruses. Disrupting this delicate balance with glyphosate can severely compromise your dog’s immune system and overall health.
Furthermore, glyphosate can directly affect your dog’s physiology. Just as it binds to nutrients and minerals in plants, it can do the same in your dog’s body, interfering with nutrient absorption and utilization. Alarmingly, glyphosate tends to accumulate in the kidneys, hindering their critical detoxification functions. Kidney disease is already the second leading cause of death in dogs, and glyphosate exposure may be a contributing factor.
Minimizing Your Dog’s Roundup Exposure: Practical Steps
Reducing your dog’s exposure to Roundup requires a multi-faceted approach:
Eliminate Roundup Use at Home: The first and most crucial step is to never use Roundup or any chemical herbicides or pesticides on your own property. Effective and safe natural alternatives for weed control are readily available, such as sprays made with vinegar, botanical oils, and soaps.
Educate Your Neighbors: While you can control your own yard, you can’t directly control your neighbors’ choices. However, you can play a role in educating them about the potential health risks of lawn chemicals to their families and pets.
Be Vigilant During Walks: Avoid walking your dog on perfectly weed-free lawns in your neighborhood. These pristine lawns are often a telltale sign of herbicide use. Be alert for warning signs indicating “recently treated” grass. Keep your dog moving past these areas and prevent them from sniffing or walking on treated surfaces.
Inquire About Park Maintenance: Check with your local parks department to determine if they use herbicides like Roundup on park grounds. Be wary of parks with uniformly weed-free grass. Keep your dog away from areas where herbicide use is suspected.
Control Grass and Plant Consumption: If your dog enjoys eating grass or plants, exercise extra caution. If you are unsure whether plants have been sprayed with herbicides, prevent your dog from consuming them.
Choose a Raw Diet: As previously discussed, transitioning to a raw diet can significantly reduce your dog’s glyphosate exposure compared to kibble. Raw diets generally contain much lower levels of glyphosate and other harmful chemicals.
Roundup Safety After Drying: A Misconception
Roundup product labels often claim that the product is safe for children and pets to walk on once it’s dry, suggesting that the chemicals have penetrated the soil to reach plant roots and are no longer a surface hazard. However, this “safety” claim is misleading and primarily refers to preventing tracking the chemicals into other areas. The label also misleadingly states that Roundup is “relatively nontoxic to dogs and other domestic animals.” Current research strongly contradicts this claim. Therefore, the safest approach is to keep your dog away from any Roundup-treated areas, regardless of whether they are wet or dry.
Mitigating Existing Roundup Exposure: Detoxification Support
Unfortunately, completely eliminating glyphosate exposure is practically impossible in today’s environment. However, research suggests that certain strategies can help mitigate the harmful effects of glyphosate and support your dog’s detoxification processes.
A 2014 study from the Faculty of Veterinary Medicine at Germany’s Leipzig University demonstrated success in reversing some of the toxic effects of glyphosate in cows. The study involved 380 dairy cows suffering from chronic botulism linked to glyphosate-contaminated GMO feeds. The cows received three supplements for several weeks:
- Charcoal: Known for its absorbent properties to bind toxins.
- Sauerkraut juice: A source of probiotics and beneficial bacteria to support gut health.
- Humic acid: A soil-derived substance with potential detoxifying properties.
After the 6-month study, the cows showed improved health and significantly reduced levels of glyphosate in their urine. Other sources also recommend bentonite clay and fulvic acid as supplements that may aid in reducing glyphosate damage.
Providing your dog with a soil-based probiotic containing humic and fulvic acid, along with bentonite clay, may help support their body’s natural detoxification pathways and reduce glyphosate toxicity.
Furthermore, a study at the University of Caen, France, investigated herbal formulas for detoxifying glyphosate in human liver cells. These formulas included:
- Dandelion (Taraxacum officinalis)
- Burdock Root (Arctium Lappa)
- Milk Thistle (Carduus marianus)
- Barberry (Berberis vulgaris)
- Greater Celandine (Chelidonium majus)
Incorporating a soil-based probiotic and considering the addition of these herbs to your dog’s diet may offer further support in mitigating the harmful effects of Roundup exposure.
While completely avoiding glyphosate is challenging, taking proactive steps to minimize exposure and support your dog’s detoxification processes can significantly contribute to their long-term health and well-being.
FAQ
Is Roundup toxic to dogs after it dries?
Yes, Roundup remains toxic to dogs even after it dries. It poses ongoing health risks by persisting in the environment and potentially disrupting their microbiome, regardless of whether the treated area is wet or dry to the touch.
Can you use Roundup near dogs?
No, it is not safe to use Roundup near dogs. Its harmful components and potential for causing serious health issues make it unsafe for use in environments where dogs are present.
What happens if a dog eats grass that was sprayed with Roundup?
If a dog ingests grass sprayed with Roundup, they can ingest harmful chemicals. This ingestion can lead to various health problems, ranging from gastrointestinal upset to more severe issues like organ damage or an increased risk of cancer over time.
Is Roundup still toxic after it dries?
Yes, Roundup remains toxic even after it dries. It continues to pose a threat to dogs by potentially disrupting their gut bacteria and creating long-term health risks through environmental contamination and persistence.
References
Mills PJ et al. Excretion of the Herbicide Glyphosate in Older Adults Between 1993 and 2016. JAMA. 2017;318(16):1610–1611.
Luoping Zhang et al. Exposure to glyphosate-based herbicides and risk for non-Hodgkin lymphoma: A meta-analysis and supporting evidence, Mutation Research/Reviews in Mutation Research, Volume 781, 2019
Takashima-Uebelhoer BB et al. Household chemical exposures and the risk of canine malignant lymphoma, a model for human non-Hodgkin’s lymphoma. Environ Res. 2012;112:171-176.
Knapp DW et al. Detection of herbicides in the urine of pet dogs following home lawn chemical application. Sci Total Environ. 2013 Jul 1;456-457:34-41.
Krüger M, Schledorn P, Schrödl W, Hoppe HW, Lutz W, et al. (2014) Detection of Glyphosate Residues in Animals and Humans. J Environ Anal Toxicol 4: 210.
Daiane Cattani et al. Mechanisms Underlying The Neurotoxicity Induced By Glyphosate-Based Herbicide In Immature Rat Hippocampus: Involvement Of Glutamate Excitotoxicity. Toxicology. 2014 Mar 14
Samsel A and Seneff S. Glyphosate’s Suppression of Cytochrome P450 Enzymes and Amino Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases. Entropy, 2013, 15, 1416-1463
Garry VF et al. Birth defects, season of conception, and sex of children born to pesticide applicators living in the Red River Valley of Minnesota, USA. Environ Health Perspect. 2002;110 Suppl 3(Suppl 3):441-449.
Shim YK, et al. Parental exposure to pesticides and childhood brain cancer: U.S. Atlantic coast childhood brain cancer study. Environ Health Perspect. 2009;117(6):1002-1006.
Céline Gasnier et al.Glyphosate-based herbicides are toxic and endocrine disruptors in human cell lines. Toxicology, Volume 262, Issue 3, 2009, Pages 184-191.
Krüger M, Shehata AA, Schrödl W, Rodloff A. Glyphosate suppresses the antagonistic effect of Enterococcus spp. on Clostridium botulinum. Anaerobe. 2013 Apr;20:74-8.
Gasnier C, et al. Defined plant extracts can protect human cells against combined xenobiotic effects. J Occup Med Toxicol. 2011 Jan 20;6(1):3.
Gasnier C, Benachour N, Clair E, et al. Dig1 protects against cell death provoked by glyphosate-based herbicides in human liver cell lines. J Occup Med Toxicol. 2010;5:29. Published 2010 Oct 27.
