Glyphosate in Dog Food: The Facts

When you eat food, you’re not simply eating the standard components of, say, a carrot or an oyster — you’re also ingesting chemicals that have been added to that food. E.g. what the carrot has been sprayed with or taken from the soil, or what the oyster has eaten or taken from the water. 

If they take these chemicals in at a faster rate than they get rid of them, it’s called bioaccumulation. 

Most modern agricultural techniques involve chemicals, such as herbicides or pesticides — and many can bioaccumulate in the food we eat. 

One chemical found in a vast amount of food, human and dog, is glyphosate. We’ve had a couple of readers write in and ask us to present the facts about what glyphosate is, where it’s found, what harm it can do, and how to avoid it.

So, we spoke to Laura Ward, our nutritionist. to get the answers to the key questions. You might find some of them alarming but that’s not our intention — we just want you to be aware of the situation.

What is Glyphosate? 

Glyphosate is a non-selective herbicide applied to the leaves to kill plants and grasses. It is one of the most widely used herbicides in the USA, found in brands such as Monsanto’s Roundup. 

Glyphosate is a strong chelating agent, meaning that it binds the soil’s minerals, making them unavailable to plants. Glyphosate targets an essential enzyme in plants, which is not found in animals. It also has potent antibiotic properties, killing bacteria in the soil, but also the beneficial bacteria of the gut microbiome. 

Why is Glyphosate found in food? 

Glyphosate sprayed onto the leaves of plants is absorbed and moves through the plant. Glyphosate has high thermal stability, which means that it is not broken down during cooking or food processing, nor it is removed by washing. This means it can remain in plant ingredients and survive the processing to create dog foods and other products. 

Is Glyphosate dangerous? 

In 2015, the World Health Organization reclassified glyphosate as a “probable human carcinogen”. Furthermore, studies have found glyphosate to have negative implications on several areas of health, including growth and development, hormones, the nervous system, digestive health and the liver. 

Laboratory studies have shown that glyphosate is connected with genotoxicity, or DNA damage. This was taken into account when researchers considered the carcinogenic potential of glyphosate. 

Damaged DNA is a key factor for cancer occurring, as the instructions within a cell for it to replicate successfully are damaged, and therefore the new cell contains unusual DNA structure. 

Scarily, this genotoxic effect can affect multiple generations. Future generations could be impacted from your dog’s glyphosate exposure, and in turn they may be affected by their parent’s exposure. 

Evidence indicates that in addition to the above-mentioned effects, glyphosate has significant negative effects on the brain and behavior and can increase the risk of some serious neurological diseases. 

Are there Acceptable Levels of Glyphosate? 

In 90-day and one-year toxicity studies in dogs, the highest value of glyphosate which provided no observed adverse effects was 100mg/kg bodyweight per day. A safety factor of 100 is applied to this, to give the established acceptable daily intake for glyphosate at 1mg/kg bodyweight per day. 

For humans the acceptable daily intake for glyphosate is 1750 mcg/kg in USA and 500 mcg/kg in EU.

Glyphosate has been found in dog foods, and the quantities varied. The levels seen were below the acceptable daily intake value for one study, and also below the acceptable daily intake level for humans in USA. Between 0.57 and 1.37 mcg/kg bodyweight per day. 

For another study the glyphosate quantity found is estimated to exceed the human acceptable daily levels by 4 to 12 times when calculated on a per kg bodyweight basis. 

How can you avoid Glyphosate? 

As glyphosate is so widespread and commonly found in products ranging from foods to other products that humans use every day, such as sanitary hygiene products, cotton and medical gauze, it makes it incredibly difficult to avoid. 

There is a correlation between the fiber content of a food and the glyphosate level, indicating that the plant portion of food and products are where glyphosate is found. There is no bioaccumulation of glyphosate in animals, so meat and animal products are not a source. 

Therefore, limiting the intake of plant-based ingredients can help to limit exposure to glyphosate. 

Choosing organic foods also helps to minimise exposure, as glyphosate is not permitted within organic farming. You can see a list of our Best Organic Dog Foods here and an article on whether organic food is better here.

As mentioned, this article isn’t intended to cause concern, but simply to explain the current situation of glyphosate use in farming crops and how this herbicide can be found in dog foods. 

References: 

1. National Pesticide Information Center – Glyphosate General Fact Sheet – http://npic.orst.edu/factsheets/glyphogen.html.
2. Food Safety Commission of Japan. Glyphosate (Pesticides). Food Saf (Tokyo). 2016 Sep 30;4(3):93-102. doi: 10.14252/foodsafetyfscj.2016014s. PMID: 32231912; PMCID: PMC6989167.
3. Karthikraj R, Kannan K. Widespread occurrence of glyphosate in urine from pet dogs and cats in New York State, USA. Sci Total Environ. 2019 Apr 1;659:790-795. doi: 10.1016/j.scitotenv.2018.12.454. Epub 2018 Dec 31. PMID: 31096409.
4. Van Bruggen AHC, He MM, Shin K, Mai V, Jeong KC, Finckh MR, Morris JG Jr. Environmental and health effects of the herbicide glyphosate. Sci Total Environ. 2018 Mar;616-617:255-268. doi: 10.1016/j.scitotenv.2017.10.309. Epub 2017 Nov 5. PMID: 29117584.
5. Bates, Nicola & Edwards, Nick. (2013). Glyphosate toxicity in animals. Clinical toxicology (Philadelphia, Pa.). 51. 10.3109/15563650.2013.851390.
6. Jiang Zhao, Steven Pacenka, Jing Wu, Brian K. Richards, Tammo Steenhuis, Kenneth Simpson, Anthony G. Hay, Detection of glyphosate residues in companion animal feeds, Environmental Pollution, Volume 243, Part B, 2018, Pages 1113-1118, ISSN 0269-7491, https://doi.org/10.1016/j.envpol.2018.08.100.
7. Madani NA, Carpenter DO. Effects of glyphosate and glyphosate-based herbicides like Roundup™ on the mammalian nervous system: A review. Environ Res. 2022 Nov;214(Pt 4):113933. doi: 10.1016/j.envres.2022.113933. Epub 2022 Jul 19. PMID: 35868581.
8. https://mypetnutritionist.com/post/glyphosate-and-my-dog/
9. Cornell University. “Glyphosate found in cat and dog food.” ScienceDaily. ScienceDaily, 24 October 2018. <www.sciencedaily.com/releases/2018/10/181024163614.htm>.