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  • Writer's pictureHolistic Equine

Is the herbicide Glyphosate causing laminitis and chronic illness in horses?

This is from an article we published a decade ago (2012) and is even more relevant today. We have updated the article with additional references at the end.

"The internal environment of the horse is a reflection of the external environmental stimulus - the same can be said of the hoof. Getting the environmental stimulus right is imperative for long term resilience and soundness in horses" - Beccy Smith, Author.


Given than glyphosate has been prevalent since the 1950's, it is reasonable to consider that glyphosate exposure to great grandparents and past generations of today's horses could lead to endocrine disorders and therefore symptoms including laminitis, for example, in current populations of horses. Furthermore, exposure to glyphosate in current populations of horses could lead to laminitis and other disease in future generations. This is a most depressing thought indeed!


This chemical potentially pervades our horse’s environment. It could be present in the vast majority of horse foods, dietary supplements and non-organic plant based bedding. It has been found in ground-water and can travel miles in the air during crop spraying where it can be ingested by plants, animals and humans.

Although apparently safe in permitted doses, Scientists have discovered that it may actually be responsible for chronic diseases in humans and other mammals.

Due to potentially higher levels present in the horse’s environment, could Glyphosate be responsible for loss of performance and disease in horses such as laminitis, PPID, metabolic syndrome/IR, navicular syndrome, gastric ulcers, leaky gut syndrome, sweet-itch and other immune conditions? Could it even contribute to fertility issues and premature death? Perhaps it causes gait anomalies, so-called saddle fitting issues and training problems too? Maybe it is involved with genetic expression or mutation and PSSM?

On a personal note...

Since our horses were exposed to glyphopsate and other agro-chemicals (over a 9 year period) at our previous properties 18 years ago, they have experienced multiple episodes of low grade laminitis and other health challenges. It has been a long journey of emotional pain for us and at times, physical pain for them but we are continuously discovering new ways to support their health and soundness. I wish to acknowledge our heartfelt appreciation of our horses and our clients horses with complex health issues as they drive us to do better, help us evolve, expand and share our knowledge and remain open to the possibility that a 'cure' is on the horizon....

Sun - distal descent and mild laminitis evidenced on radiographs following an inflammatory episode. 3 cycles of Formahoof helped grow a healthy capsule and increased sole depth significantly

Background Information

Glyphosate (the active ingredient of Roundup ®) is the most popular herbicide in the EU and increasingly throughout the world. Its use is on the increase in the last decade due to reduced costs of the chemical and the adoption of genetically modified (GM) crops (called “Roundup Ready®”) which are resistant to its toxic effects. In addition, weed resistance is leading to higher rates and frequency of application, leading to a rise in residue levels. The EU’s maximum glyphosate levels permitted in crops is set to rise as the industry anticipates greater levels used, however standards for residues in animal feed are far higher. The raise in permitted levels is not apparently related to its safety and the effects on animal health from ingestion of residues have been largely ignored.

It is difficult to get information about actual amounts of glyphosate in food and the environment as it is perceived to be non-toxic. The notion that it is safe has been popularized by Monsanto and as a consequence, farmers have not exercised caution in its application to crops. As such, during application it can be breathed in by animals and people and can drift onto nearby grazing paddocks and hay fields and finds its way into water sources. It is inevitably found in variable amounts in manure from exposed animals as well as human and animal food sources. It has been found in the eggs, milk and meat of livestock fed permitted levels of glyphosate in their feed and even in human urine. No long-term tests have been conducted on the health effects of glyphosate in humans and certainly there have been no scientific tests done on the effect of glyphosate on the health of horses.

Many crops are exposed to glyphosate; however, the most influential source of potential exposure in the horse are found in soy, wheat, oats, barley, peas, corn, sugar, carrots, linseed, rapeseed, sugar-beet and even forages such as alfalfa and grass hay. The by-products and derivatives of these crops also may contain glyphosate. Management practices and proximity of horses to non-organic agricultural activity make horses especially vulnerable to glyphosate exposure.

Is Glyphosate Harmful?

There is research to indicate that Glyphosate may be toxic to mammals. While short term tests on rodents have shown no apparent toxicity; tests involving life-long exposure in rodents have shown a decreased lifespan, liver and kidney dysfunction and an increased risk of cancer. In addition, it has been correlated to manifestation of disease in future generations, despite these generations having NOT been exposed to glyphosate!

Glyphosate inhibits cytochrome (CYP) enzymes. These enzymes play many crucial roles in maintaining homeostasis including detoxification of xenobiotics. Xenobiotics are foreign chemical substances found within the body. CYP enzymes are also important for hormone synthesis and breakdown (including oestrogen and testosterone synthesis and metabolism), cholesterol synthesis, and vitamin D metabolism.

Glyphosate is thought to disrupt the shikimate pathway of plants and the industry claims it is therefore safe for mammals as this pathway does not exist in mammals. However, it does exist in gut bacteria which play an important role in physiology including the detoxifying of xenobiotics, vitamin synthesis, immune system homeostasis, aid digestion and modulate the gut membrane permeability. Glyphosate exposure can cause gut dysbiosis and associated conditions including inflammatory bowel disorders. There are 10 bacteria cells for every single human cell so when considering the gastrointestinal tract of the horse; they have probably an even greater ratio of bacteria. The potential for loss of homeostasis and development of disease due to glyphosate is arguably greater in the horse than in the human.

Glyphosate has been linked to endocrine disorders, obesity, fertility problems, methylation problems (and detoxification pathways) and chronic disease. It is associated with depleted sulphate levels, impaired nutrient absorption and even anorexia nervosa.

Glyphosate has been linked to inducing transgenerational inheritance of disease and germline (e.g. sperm) epimutations, including the above mentioned conditions, suggesting future generations of people, farm animals and horses are at risk of developing pathology even when they have not been exposed to glyphosate. This suggests that generational toxicology of glyphosate needs to be considered in the disease etiology of future generations.

It is hypothesized that health concerns associated with a modern western diet could be explained by biological disruptions that have been attributed to glyphosate. These include obesity, digestive disorders, Alzheimer’s disease, depression, autism, Parkinson’s disease, cancers and others. Other environmental toxins are undoubtedly contributing but the insidious and accumulative effects of glyphosate make it the prime candidate for increasingly common metabolic disorders in humans.

Hypothesised link between Glyphosate and loss of health in domestic horses

The horse is a non-ruminant herbivore. It could be argued that the health of the horses gut determines the health status of the horse and therefore his ability to perform. Given the scientific data and arguments, the possible effect of glyphosate on horses could be summarized as impaired homeostasis and metabolic function leading to chronic disease, loss of performance and even premature death.

Given the complexity with which glyphosate is thought to affect mammals, the following signs or diseases could indicate glyphosate exposure in horses:

  • Behaviour associated with gut dysbiosis, e.g. “girthiness”, saddle fitting issues, lameness or gait anomaly (especially involving the right hind limb), poor performance, training issues, cribbing or wind sucking, box walking, depression, etc.

  • Diseases associated with gut dysbiosis

  • Obesity (with or without fat pads)

  • Anorexia, muscle loss or malnutrition

  • Back pain/hind limb lameness/suspensory ligament “diseases”

  • Exercise intolerance/chronic fatigue

  • “Lifestyle” diseases such as insulin resistance, PPID and metabolic disease

  • Navicular syndrome/disease (or other non-trauma lameness involving the musculo-skeletal system)

  • Equine Digital Osteoarthritis / laminitis / weak or deformed hooves

  • Fertility problems

  • Liver/kidney disease

  • Colic

  • Increased incidence and severity of infections, including parasites

  • Allergies and intolerances such as sweet-itch and an intolerance to grass

  • Increased chemical sensitivity with reactions and loss of health in response to wormers, vaccinations, medications and environmental pollutants

  • PSSM / RER and its’ many symptoms and variants

This list is not exhaustive and clearly more research needs to be done on the effects of glyphosate on horses.

Practical implications

Laminitis is increasingly associated with metabolic dysfunction. It could be argued that the possible triggers for the most prevalent form of modern laminitis (pain, stress, NSC, grass, medications, vaccinations, chemical wormers, environmental toxins, etc) only actually result in laminitis because of the accumulative effect of glyphosate and other environmental toxins on the metabolism of the horse. I believe modern management and grazing methods contribute to impaired nutritional state and imbalance and exposure to glyphosate could exacerbate this and lead to disease, grass sensitivity and laminitis.

If you suspect your horse is metabolically impaired, seek advice from an appropriate nutritionist and company such Thunderbrook Equestrian. Discuss with your vet and professional team an appropriate, holistic and efficacious management plan to control or even reverse the condition. Seek help from a suitably qualified holistic hoof care professional who properly balances hoof to foot around the axis of the limb and find a good body worker or alternative therapist who can help with poor postural conformation and soft tissue imbalance which can occur with prolonged dysbiosis and GI tract imbalance. Consider an integrated approach which is holistic in nature. Consider also how horses are managed and seek a more natural management system which supports the environment too such as Equicentral System.

Holistic Equine (and Holistic Reflectionc CIC) provide unique holistic services including:

Management and Prevention

Quite simply;

  • avoid management practices and stress which burden the horse unnecessarily with chemicals, toxins and potential irritants, such as stressed pasture, clover and rye grasses as well as glyphosate

  • feed the horse like a horse and therefore promote proper gastro-intestinal tract functionality,

  • promote proper hoof structures and functionality through proper stimulus and exercise, this is critical – check out our blog posts at

  • adopt a holistic and organic management system (see for more info)

  • stable and ride your horse in an appropriate environment and consider adopting an Equicentral System (and away from intensive agricultural environment),

  • understand exactly what is in your horses feed and supplements and how your horses forage is produced and if it contains agricultural by-products and potential gastro-intestinal irritants, avoid feeding them.

  • visit for info, advice and products on reversing grass sensitivity, laminitis and other signs associated with nutritional imbalance. Other feed and supplement companies/experts can also help – do your research!

  • consider the impact we (and our energy field) have on the horse’s well-being and resilience. Studies by the Heart Math Institute demonstrate a clear link between our state of being and level of coherence (harmony) between our heart and brain and our health. In addition, our state of coherence or incoherence has a direct impact on the horse’s well-being. If the humans around a horse make a conscientious efforts to remain in cohesion, we could better support our own as well the horses well-being and resilience! For more info, visit


There is evidence to associate the increasing use of glyphosate with increasing occurrence of chronic illness in the western world. Association does not demonstrate causation, however there are demonstrated mechanisms by which glyphosate may be instrumental in causing metabolic imbalance in horses and ultimately laminitis and other so-called lifestyle metabolic diseases. The evidence demonstrates that further research on glyphosate and laminitis is imperative and exposure should be avoided.

Given than glyphosate has been prevalent since the 1950's, it is reasonable to consider that glyphosate exposure to great grandparents and past generations of horses could lead to endocrine disorders and therefore symptoms including laminitis, for example, in current populations of horses. Furthermore, exposure to glyphosate in current populations of horses could lead to laminitis and other disease in future generations. This is a most depressing thought indeed!

In many cases we have been involved with, the hoof tells a story of the horses state of health. Identifying poor hoof ideals can be the first step in recognising all is not well with your horses/and/or its environment. An integrative approach is imperative to helping promote and maintain a healthy, resilient and sound horse. We highly recommend our enlightening and comprehensive equine podiatry consult services to help promote a PRO-Active approach to whole horse and hoof health - which can be in-person (and include hoof care/trimming) or remote via our online consult service...


Mesnage, R., Arno, M., Costanzo, M. et al. Transcriptome profile analysis reflects rat liver and kidney damage following chronic ultra-low dose Roundup exposure. Environ Health 14, 70 (2015).

Samsel, A.; 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.

Kubsad, D., Nilsson, E.E., King, S.E. et al. Assessment of Glyphosate Induced Epigenetic Transgenerational Inheritance of Pathologies and Sperm Epimutations: Generational Toxicology. Sci Rep 9, 6372 (2019).

Beck, D., Nilsson, E.E., Ben Maamar, M. et al. Environmental induced transgenerational inheritance impacts systems epigenetics in disease etiology. Sci Rep 12, 5452 (2022).


We take an integrative and holistic approach to whole horse hoof and body health. We appreciate the relationship between body, limb and hoof and seek to address imbalances while positively influencing appropriate static and dynamic hoof balance and biomechanics.

If, like our clients, you want to learn a PRO-Active approach to hoof care and wish to prevent lameness in your horse, consider booking us for an Integrative Podiatry Consult, join our academy for on-line courses, events and mentorship opportunities or join our new VIP membership where you can learn top tips straight from an expert!

Please feel free to share, ask questions or reach out for further support!


Beccy Smith BSc ADAEP EBW

Diploma in Advanced Applied Equine Podiatry and Independent Equine Podiatrist, Consultant and Therapist

CEO and Founder of 100% Non-Profit Community Interest Company Holistic Reflections CIC

Holistic Reflections CIC – a 100% non-profit organisation promoting wellbeing and resilience in people, horses and the environment - for the benefit of all.

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