A Rash of Roundup: Glyphosate Sensitivity in Horses

Last September, a vet-tech friend of mine in Texas, Lizzy Meyer, alerted me to the fact that her horse, Elto, had developed what she suspected was a glyphosate sensitivity.  Glyphosate is Monsanto’s herbicide with the trade name  Roundup.  Elto’s symptoms included itchiness, hot spots, and edema over the kidneys.  He spent a lot of time lying down and chewing on his legs. He constantly rubbed his mane and tail, which she initially suspected was sweet itch.

She tried various remedies including homeopathics and topicals.  Nothing worked.  Finally she took the hay away and within a few days he was less itchy.  She started him on spirulina (via Biostar’s Optimum EQ) and liver detoxifying herbs and he steadily improved.  Then she went in search of information on the local hay she had purchased…and discovered that it had been grown with Roundup.

The reality of Roundup:
Glyphosate is the most widely used herbicide in the world.  It is used on: hay, oats, rice, wheat, barley, corn, beet pulp, soybeans, alfalfa, peas, carrots, sunflower seeds, peppermint, wild rice, mustard, pumpkins, squash, rye, flax, chickpeas, beans, molasses, sweet potatoes, canola, hops, and sugarcane.

It is not only used to reduce weeds during the growing season, it is now recommended by its manufacturer, Monsanto, for use as a desiccant prior to harvesting to even out ripening and speed up the drying process.

Roundup is also used in some orchards around the base of fruit trees, which studies have shown can decrease the nutritional quality of the fruit, while also destroying important soil flora and mineralization.

According to US government data, glyphosate use in the US has increased from 49,000 tons in 2002 to 128,000 tons in 2012; or approximately 280 million pounds of glyphosate

The Residue:
A study from the Arctic University of Norway (published June 2014 in Food and Chemistry) compared 31 different soybean plants on Iowa farms and compared the accumulation of pesticides and herbicides.  The scientists found high levels of Roundup on 70% of genetically engineered soy plants.  Monsanto has defined an “extreme level” of Roundup as 5.6 milligrams per kilogram of plant weight, but the scientists found 9 milligrams of Roundup per kilogram: almost double the amount of what Monsanto describes as extreme.

The scientists concluded:
“This study demonstrated that Roundup Ready GE-soy may have high residue levels of glyphosate …Lack of data on pesticide residues in major crop plants is a serious gap of knowledge with potential consequences for human and animal health.”

Glyphosate maximum residue levels:
As one might expect, the EU has lower permitted Maximum Residue levels (MRLs) of glyphosate than the US.  For example corn in the EU can not exceed 1ppm(parts per million) of MRLs, while in the US corn can be at 3.5ppm of MRLs.  Sunflower seeds in the EU cannot exceed 20ppm but in the US, 40ppm is permitted.

Did you say Sunflower seeds?
This is another part of the glyphosate story.  A month ago, my friend Lizzy who suspected glyphosate sensitivity in her mustang, Elto, started feeding sunflower seeds.  It didn’t take long and he had another reaction, like the one he’d had with the glyphosate hay.  Like many of us, Lizzy hadn’t suspected or even guessed that sunflower seeds would be grown with glyphosate.

Glyphosate residues in Germany:
A recent study on glyphosate residue carried out by the Heinrich Böll Foundation analyzed glyphosate residue in urine of 2,009 Germans.  Glyphosate residues were recorded in 99.6% of the people monitored.  75% of the group displayed levels five times higher than the legal limit of glyphosate in drinking water.  This study was the largest of its kind ever carried out.

Another study published in Feb 2016 by the Munich Environmental Institute found glyphosate readings in 14 of Germany’s most popular beers between 0.46 and 29.74 micrograms per liter.  The highest reading was 300 times the legal limit of glyphosate in drinking water in Germany. Geneticist Sophia Guttenberger of the Munich institute said: “glyphosate should simply be neither in beer nor in our bodies.”

Glyphosate interferes with GI tract bacteria:
Glyphosate kills plants by interfering with a biochemical pathway involved in the synthesis of amino acids called the shikimate pathway.  This pathway is not found in humans; however, the pathway is found in bacteria, and bacteria are critical to the GI tract to synthesize the essential amino acids.

By interfering with the biochemistry of bacteria in the GI tract, consumption of glyphosate depletes essential amino acids and can bind to important minerals like copper and zinc.

Authors of a 2013 study in the scientific journal Entropy reached an interesting conclusion:
“Contrary to the current widely-held misconception that glyphosate is relatively harmless to humans, the available evidence shows that glyphosate may rather be the most important factor in the development of multiple chronic diseases and conditions that have become prevalent in Westernized societies”. (Samsel, A., and Seneff, S. 2013. Glyphosate’s Suppression of Cytochrome P450 Enzymes and Amino Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases. Page 1443.  Entropy, 15, 1416-1463)

A study examining the effect of glyphosate on GI tract bacteria of chickens found that the beneficial bacteria: Lactobacillus, Bacillus, Bifidobacterium, and Enterococcus were reduced at low concentrations of glyphosate.  However, harmful bacteria including salmonella grew successfully exposed to the same levels of glyphosate. 

A similar study on cattle found that glyphosate was toxic to beneficial bacteria in the GI tract and that glyphosate residues in cattle feed may predispose cattle to infection by Clostridium botulinum, the bacteria that causes botulism.

What do we do now?
Buying organic food ingredients is an alternative, as glyphosate is not permitted in organically grown food.  Finding organic hay, or hay that has not been grown with glyphosate is a major challenge. 

Foods labeled as non-GMO does not mean that those foods are glyphosate free.

Research has led me to identify some foods that may help reduce chronic glyphosate sensitivity. These foods include:

1. Blue green algae (Spirulina): This nutrient-dense super food has been shown to reduce heavy metal poisoning.  With its high chlorophyll content it can bind with toxic metals and research has shown it can do the same with some carcinogens.  It is a rich source of SOD, a super antioxidant.

2. Organic oranges/organic tangerines: Contains limonene and flavonoids that can induce the enzyme activity of glutathione S-transferase, which is an important detoxifying enzyme.

3.  Sulfur foods: Kale’s high sulfur compounds help support aspects of cellular detoxification, and healthy oxygen transport.

4.  Probiotics: Supplementing with multi-strain, active probiotics, particularly the cooling bacteria Lactobacillus family ensures a healthy bacterial balance in the GI tract.  Remember that to colonize the GI tract of equines, we need a minimum of 100 Billion CFUs (Colony Forming Units).

5.  Bentonite or Smectite clays:  Can adsorb and absorb toxins because of   clay’s negative electrical charge that attracts positively charged toxins, while also acting as a sponge, drawing impurities into its internal structure.

Biostar’s Optimum line of multi vitamin/minerals provides spirulina, whole oranges, and kale.  Biostar’s Rebound EQ includes Smectite clay and our proprietary probiotic blend.

Glyphosate-free Foods:
Foods not grown or harvested with glyphosate include: chia, coconut meal and oil, hemp seeds and oil, and camelina oil.

Glyphosate sensitivity in horses:
At present there is no research on glyphosate sensitivity specifically for equines.  It is a theory based on observation and studies done on humans, cattle, mice, and chickens. Several holistic practitioners have contacted me about suspected glyphosate sensitivity in client’s horses.  I am starting to wonder if glyphosate sensitivity may play a role in ulcer formation, although I have no proof that it is so.  If glyphosate sensitivity is suspected, it is recommended to adjust the diet to include the suggested foods listed above.

Other Resources:

• New Country Organics (Virginia): Organic alfalfa pellets, rice bran, oats, and flax. 
• Green Mountain Feeds (Vermont): Source for organic alfalfa pellets, barley, corn, and whole oats.  
• Grow Organic (northern California): Organic alfalfa pellets 
• Organic Hay Company (Berkshire, NY): Organic timothy and mixed grass blend
• Starwest Botanicals (California): Bulk organic herbs
• Mountain Rose Herbs (Oregon): Bulk organic herbs and spices