06
Jun
Pesticide Residues in Pet Food Threaten Health of Companion Animals; Regulatory Deficiencies Cited
(Beyond Pesticides, June 6, 2025) Published in Environmental Pollution, a study of commercial dry pet products finds dietary pesticide residues in dog and cat food, “highlighting the urgent need for improved regulatory frameworks to address the presence of non-approved pesticides in pet food.†Additionally, the researchers point out: “Current regulatory frameworks primarily assess the toxicity of individual pesticide compounds, yet real-world exposure involves complex mixtures that may lead to additive or synergistic effects. The presence of multiple residues in a single sample suggests that companion animals may be subjected to combined toxicological burdens that are not yet fully understood.†(See studies here, here, and here.)
The researchers assess pesticide contamination, and their associated toxicological risks, in 83 total food products for dogs (43) and cats (40). Of the foods tested, the researchers found a total of 51 pesticides, many of which are banned in the European Union (EU), including 47% fungicides and 37% insecticides.
“Pesticide residues in pet food pose potential risks to animal health, yet their occurrence and dietary exposure in companion animals remain largely unexplored,†the authors state. They continue: “To our knowledge, this is one of the first comprehensive investigations assessing both pesticide prevalence and potential dietary exposure in companion animals. Previous research has primarily focused on the presence of contaminants in livestock feed, with limited attention given to pet food safety.â€
To address this gap, this study focuses on dog and cat food, especially given the distinct dietary patterns and metabolic processes in these animals that are significantly different from farm animals. This also aligns with the increasing demand for high-quality pet nutrition. In Spain, where the study was conducted, the researchers report that, “… [the] pet population includes approximately 9.3 million dogs and 5.9 million cats. Dry food remains the dominant segment, representing 88.1% of dog food sales and 74.8% of cat food sales. This market expansion underscores the need for continuous monitoring of pet food safety and quality.â€
Since pet food can contain many plant-based ingredients, there is a high risk of contamination from pesticides used in chemical-intensive conventional agriculture. Cereals (like corn, rice, wheat, barley, and sorghum), as well as various vegetables (such as peas, potatoes, carrots, and legumes), are often used in modern pet food formulations.
As the authors note: “[T]he increasing use of plant-based ingredients in pet food formulations has raised concerns about the presence of contaminants, particularly pesticide residues. Many pesticides applied during the cultivation, transportation, and storage of raw materials persist in the final pet food product.†(See studies here and here.)
They continue: “Additionally, animal-derived ingredients contribute to contamination, as pesticide residues bioaccumulate in livestock tissues used as protein sources in pet food. This dual exposure from both plant- and animal-based ingredients underscores the need for systematic monitoring of pesticide residues across all components of pet food formulations.â€
Study Methodology
The study’s aim, as the researchers share, is to conduct a comprehensive analysis of pesticide residues in commercial dog and cat food by determining the prevalence of pesticide residues in a wide range of pet food products, comparing detected levels with existing maximum residue limits (MRLs) for livestock feed, and evaluating the potential toxicological risks associated with chronic exposure in companion animals.
The 83 food products were obtained from “retail outlets, specialized pet stores, and supermarkets in Gran Canaria (Canary Islands, Spain), reflecting Spain’s predominant sales distribution patterns, as reported by distributors,†the authors say. The products encompass a range of price points, brands (only internationally and nationally distributed brands were considered), and ingredients, with at least 40% of the samples containing vegetables in order to represent plant-based formulations.
In explaining the methodology, the researchers state: “To estimate the dietary exposure to pesticide residues in companion animals, the estimated daily intake (EDI) was calculated for each pesticide detected in dry pet food samples. The EDI was determined by multiplying the concentration of each pesticide residue in a given sample by the recommended daily consumption (g/kg body weight/day) provided by the manufacturer for that specific product. This approach allowed us to estimate exposure levels relative to body weight basis for both dogs and cats, accounting for species-specific dietary variations.â€
Cumulative exposure to pesticides was also evaluated by using a Hazard Index (HI) for the pesticide classes, including herbicides, fungicides, insecticides, acaricides, and post-harvest preservatives. “This classification accounts for differences in modes of action and potential toxicological interactions within each category,†the authors explain. “Additionally, a total cumulative HI was calculated to provide an overview estimate of pesticide exposure in pet food.†This approach, however, does not account for synergistic effects of pesticide mixtures that can amplify adverse health outcomes.
Results
Of the 51 pesticides identified in at least one sample of the pet food products, 19 (37.25%) are banned in the EU. “A key finding of this study was the high prevalence of unapproved pesticides in the analyzed samples,†the researchers state. “These include long-banned substances such as atrazine (herbicide), chlorpyrifos (insecticide), and carbendazim (fungicide), which were prohibited due to their environmental persistence and potential toxicity to non-target species.â€
This is of great concern, as the study points out: “Compounds such as chlorpyrifos, carbendazim, and atrazine have been linked to neurotoxicity, endocrine disruption, and long-term ecological damage. The continued presence of these substances in commercial pet food suggests potential contamination of raw materials, insufficient regulatory oversight, or unauthorized use in certain agricultural practices.† (See studies here, here, and here.)
Nineteen of the pesticides also exceed the MRL for feed materials under the EU Commission Regulations. The authors continue, reporting that, “Pesticide residues were significantly more prevalent in pet food containing vegetable ingredients. Although pesticide residues were detected more frequently in dog food than in cat food, total pesticide concentrations did not significantly differ between species.â€
The estimated daily intake (EDI), however, was calculated and reveals significant differences in exposure levels for specific compounds between dogs and cats. “Pet foods containing vegetables, fruits, or cereals had higher total pesticide concentrations than those formulated exclusively with animal-based ingredients,†the researchers note. “This finding aligns with the widespread use of pesticides in crop production and post-harvest treatments, suggesting that plant-based components in pet food are a primary source of pesticide residues.â€
Notably, the results reveal certain pet food brands contain “particularly high contamination levels, with up to 20 pesticide residues detected in a single dog food sample and 21 in a single cat food sample, respectively.†This did not, however, correlate with price point or type of brand (store brand vs. commercial). “Despite the common perception that premium-priced pet foods may adhere to stricter quality standards, our results indicate that pesticide contamination is independent of product price,” the authors say.
Although the Hazard Index (HI) calculations, to assess the potential risk posed by cumulative pesticide exposure, were “below the critical threshold of 1, indicating that individual pesticide exposure levels do not pose an immediate toxicological risk, chronic exposure effects remain uncertain.†(See studies here and here.)
Regulatory Deficiencies
Due to regulatory uncertainties, the cumulative risks of prolonged dietary pesticide exposure to pets need to be evaluated. As the authors stress, not only do the long-term effects of chronic low-dose exposure to pesticide mixtures have uncertain effects, but there is also an “absence of specific maximum residue limits (MRLs) for pet food [that] underscores the need for stricter regulations and systematic monitoring to ensure long-term safety.†Since pet food formulations are vastly different from livestock feed, current regulatory frameworks specifically addressing contaminants in companion animal diets are necessary.
The authors conclude: “From a regulatory standpoint, our findings highlight the urgent need for stricter monitoring and enforcement of pesticide residue limits in pet food… The absence of specific guidelines for companion animal diets represents a significant regulatory gap that should be addressed to ensure the long-term safety of pets.†(See additional Daily News coverage on pet health here.)
Previous Research
In the study, various scientific literature is cited that supports the results. This includes:
- “Previous studies have identified pesticide residues in the serum, hair, and urine of companion animals, indicating exposure through both dietary and environmental sources.†(See here, here, and here.)
- “[C]hronic exposure to low doses of neurotoxic and endocrine-disrupting pesticides has been linked to various health concerns in humans and wildlife, raising concerns about potential long-term effects in pets.†(See studies here, here, and here.)
- “Chronic pesticide exposure is linked to significant health risks in companion animals, including cancer and endocrine disorders. Epidemiological studies associate pesticide exposure with a higher incidence of malignant lymphoma in dogs, and transitional cell carcinoma of the bladder, particularly in genetically predisposed animals.†(See here, here, and here.)
- A study finds “exposure to pesticide residues has been implicated in the development of mammary tumors in dogs.â€
- “In cats, chronic exposure to environmental contaminants, including pesticides, has been strongly associated with hyperthyroidism.â€
- Studies (see here and here) show that “grains and legumes in pet food formulations often contain pesticide residues due to pre- and post-harvest treatments. While plant-derived ingredients may provide nutritional benefits, their inclusion also represents a potential risk factor for increased exposure to pesticide residues.†(See studies here and here.)
- “As pets consume the same diet daily over extended periods, even low-level chronic exposure to these pesticides may pose health risks, particularly in species with limited detoxification capacities, such as cats.†(See here and here.)
Organic Solution
As Beyond Pesticides has previously reported, upholding, and continuously improving upon, organic standards in food production is the solution for protecting the health of all organisms. Beyond Pesticides continues to urge the United States Department of Agriculture (USDA) to bring pet food production and materials standards in line with organic standards.
📣 TAKE ACTION on USDA’s proposal to rescind the organic pet food rule HERE! Public comments are due by Thursday, June 11, 2025, at 11:59 PM Eastern! This follows an Action of the Week from 2024 (Tell USDA To Ensure that Certified Organic Fungi and Pet Food Are Truly Organic).
In the context of upholding organic integrity and growing the market, Beyond Pesticides offers a perspective that it believes strengthens the value of protecting health and environment through a holistic systems approach to food production and processing—applying the principles and practices to all land management. This contrasts with chemical-intensive farming and land management with its reliance on petrochemical pesticides and fertilizers that contribute to the current existential health, biodiversity, and climate crises.
For additional Beyond Pesticides’ coverage on the threats of pesticides to pets and how to keep your companions safe, see here and here. Learn more about the health and environmental benefits of organic land management, as well as Buying Organic Products (on a budget!). Support Beyond Pesticides’ mission of eliminating the use of petrochemical pesticides and synthetic fertilizers by 2032 by donating today. Â
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
MacÃas-Montes, A. et al. (2025) Pesticides residues in pet food: A market-based study on prevalence and toxicological implications, Environmental Pollution. Available at: https://www.sciencedirect.com/science/article/pii/S0269749125007729.
