Glyphosate in Pet Food

Glyphosate is a broad-spectrum systemic herbicide and crop desiccant, widely recognised as the active ingredient in the commercial weed killer Roundup. It is used in both large-scale agriculture and domestic gardening to control unwanted plants.

Originally discovered in 1950 by Swiss chemist Dr. Henri Martin, glyphosate was initially not considered commercially valuable for pharmaceutical purposes and was transferred between companies for various trials. Its herbicidal properties were identified in 1970 by a Monsanto chemist, leading to its registration as an herbicide in 1974. In 2010, Monsanto was granted a patent recognising glyphosate’s antimicrobial effects.

While effective in agriculture, glyphosate use has raised significant health concerns. In 2015, the International Agency for Research on Cancer (IARC) classified glyphosate as “probably carcinogenic to humans” based on limited evidence in humans and sufficient evidence in animals. In 2018, Monsanto (now Bayer) was found liable in a U.S. court for the cancer diagnosis of groundskeeper Dewayne Johnson, resulting in widespread public attention. Since then, at least 32 countries have restricted or banned glyphosate use.

Why Glyphosate is a Concern for Dogs Pet exposure to glyphosate can occur through: Diet – Many processed pet foods contain grains and legumes treated with glyphosate before harvest (a process known as desiccation). Research has shown higher glyphosate residues in grain-based pet foods compared to fresh diets. Environmental Contact – Routine council spraying of public areas, including parks and footpaths, can result in dogs walking through treated zones. Home Use – Glyphosate-based products used in domestic gardens can be tracked indoors on paws and absorbed through the skin or ingested during grooming. Glyphosate is not only a potential carcinogen but also acts as a broad-spectrum antimicrobial. This means it can disrupt the gut microbiome by killing beneficial bacteria, potentially contributing to dysbiosis, inflammation, and impaired immunity. Chronic low-level exposure is of particular concern, as it may accumulate over time and contribute to long-term health problems. Minimising Glyphosate Exposure for Dogs Pet owners can take practical steps to reduce their dog’s glyphosate intake: Wash Paws After Walks After visiting parks, sports fields, or suburban nature strips, wash your dog’s paws and underbelly to remove potential chemical residues. Avoid Using Glyphosate at Home Choose safer alternatives such as boiling water, vinegar-based sprays, or manual weeding to control unwanted plants. Improve Dietary Quality Select certified organic foods where possible. Choose products with minimal or no grain and legume content. Consider fresh, home-prepared diets where ingredient sourcing can be controlled. For those feeding commercial food, look for suppliers who source ingredients from countries with glyphosate restrictions or bans. Why This Matters Chronic glyphosate exposure may impact a dog’s health in multiple ways, including increasing cancer risk, contributing to gut dysbiosis, affecting nutrient absorption, and potentially influencing behaviour through the gut–brain axis. By understanding exposure pathways and making small but consistent changes, pet owners can reduce the chemical burden on their animals, supporting longevity and overall health.