As there is currently no clear, shared definition of what constitutes risk-based use in practice, the initial focus has been reducing environmental exposure following a decision to treat. This reflects the need to take proportionate action while the evidence base is further developed. In parallel, work is ongoing to build the scientific and behavioural evidence needed to support a more targeted approach.

The Call for Evidence sought data on the environmental impacts of all flea and tick products containing fipronil or imidacloprid, including those with a distribution category of POM-V. Anybody was able to contribute evidence, with the aim of understanding how restricting the supply route for these products might impact pet owners, animal health and welfare, environmental outcomes, businesses, and the wider sector.

The Veterinary Medicines Directorate (VMD) leads the cross‑government Pharmaceuticals in the Environment (PiE) Group and is engaging with stakeholders on the environmental risks of flea and tick treatments containing fipronil and imidacloprid.

Engagement has included several meetings with individual organisations, including the British Veterinary Association, the RSPCA and the pharmaceutical industry, as well as a PiE stakeholder workshop in Summer 2025 involving veterinary professionals, charities, retailers, industry and academia.

The VMD has also launched an eight week Call for Evidence as part of its review of the distribution categories of veterinary medicines containing fipronil or imidacloprid. This open process invites evidence and views from all interested stakeholders to ensure that any future regulatory decisions are informed by robust evidence and consider impacts on animal health and welfare, the environment, pet owners and businesses.

No decisions have yet been taken on regulatory changes, and stakeholder engagement will continue as the evidence base is considered.

The Government continues to work towards our obligation to restore water bodies to good ecological status and remains committed to securing continuous improvement for the water environment.

The Government has committed in the White Paper to exploring setting new ambitious overarching targets for the water environment. This would enable consistent national oversight and alignment between government, regional water planning, regulators, the water industry and the private sector to better deliver agreed outcomes while maintaining environmental standards.

The Veterinary Medicines Directorate continues to contribute to its commitments under the Pharmaceuticals in the Environment Roadmap, evidence‑gathering, stakeholder engagement and regulatory review activity relating to fipronil and imidacloprid.

The Veterinary Medicines Directorate (VMD) leads the cross‑Government Pharmaceuticals in the Environment (PiE) Group and has published a roadmap responding to fipronil and imidacloprid detected in UK waterways. While the VMD does not undertake environmental monitoring of these substances, we liaise with the environment agencies that do, all of whom are represented on the PiE Group.

VMD‑funded studies show that topical spot‑on flea and tick products can contribute to environmental levels through wastewater pathways and when treated dogs swim.

Routine or preventive use may contribute to environmental inputs; however, there is no shared definition of risk‑based use across the companion animal sector. Prophylactic treatment may be appropriate in some cases, in the prevention of parasitic disease and zoonotic transfer, and the clinical justification for the decisions made by the attending veterinarian for such use is overseen independently of the VMD.

The VMD is funding research on how pet owner behaviours influence environmental outcomes to inform future communications and policy to promote responsible use. Alongside this, the VMD will launch national stewardship messaging in spring 2026 and is reviewing distribution categories to consider whether professional advice should be required at point of sale, helping protect both animal health and the environment.

Environmental quality standards are fundamental to the effective assessment and regulation of chemical impacts. This commitment has already been made in the roadmap produced by the cross-Governmental Pharmaceuticals in the Environment group.

The Government has set out its new vision for water through a White Paper published on 20 January 2026. The White Paper sets out once in a generation reforms that will transform the water system for good. It sets out how we will deliver on our promise to clean up our rivers, lakes and seas – not just for today, but for generations to come. We have committed to explore setting new ambitious overarching targets for the water environment. In the meantime, we continue to work towards our obligation to secure continuous improvement for the water environment.

Environmental quality standards are fundamental to the effective assessment and regulation of chemical impacts. This commitment has already been made in the roadmap produced by the cross-Governmental Pharmaceuticals in the Environment group.

The Government has set out its new vision for water through a White Paper published on 20 January 2026. The White Paper sets out once in a generation reforms that will transform the water system for good. It sets out how we will deliver on our promise to clean up our rivers, lakes and seas – not just for today, but for generations to come. We have committed to explore setting new ambitious overarching targets for the water environment. In the meantime, we continue to work towards our obligation to secure continuous improvement for the water environment.

Environmental quality standards are fundamental to the effective assessment and regulation of chemical impacts. This commitment has already been made in the roadmap produced by the cross-Governmental Pharmaceuticals in the Environment group.

The Government has set out its new vision for water through a White Paper published on 20 January 2026. The White Paper sets out once in a generation reforms that will transform the water system for good. It sets out how we will deliver on our promise to clean up our rivers, lakes and seas – not just for today, but for generations to come. We have committed to explore setting new ambitious overarching targets for the water environment. In the meantime, we continue to work towards our obligation to secure continuous improvement for the water environment.

The Veterinary Medicines Directorate (VMD) is taking a range of actions to address the levels of fipronil and imidacloprid being detected in UK waterways.

Through its leadership of the cross‑Government Pharmaceuticals in the Environment Group, the VMD has published a roadmap focusing on improving public awareness and promoting responsible use and disposal of topical flea and tick treatments.

To strengthen the evidence base, the VMD is funding research into environmental exposure pathways and pet owner behaviours and is working with environment agencies to improve monitoring data.

The VMD is also undertaking an evidence‑based review of distribution categories for veterinary medicines containing fipronil or imidacloprid.

The Veterinary Medicines Directorate (VMD) is taking a range of actions to address the levels of fipronil and imidacloprid being detected in UK waterways.

Through its leadership of the cross‑Government Pharmaceuticals in the Environment Group, the VMD has published a roadmap focusing on improving public awareness and promoting responsible use and disposal of topical flea and tick treatments.

To strengthen the evidence base, the VMD is funding research into environmental exposure pathways and pet owner behaviours and is working with environment agencies to improve monitoring data.

The VMD is also undertaking an evidence‑based review of distribution categories for veterinary medicines containing fipronil or imidacloprid.

The Veterinary Medicines Directorate (VMD) has undertaken a number of research activities to strengthen the evidence base on how fipronil and imidacloprid from topical flea and tick treatments may enter and affect the environment. Recently published VMD‑funded studies (2024–25) demonstrated that spot‑on flea and tick products can contribute to environmental residues through wastewater pathways and when treated dogs swim, providing the first UK‑specific exposure data for these routes. To build on this, the VMD has commissioned further work to address key evidence gaps identified at the 2025 Pharmaceuticals in the Environment (PiE) stakeholder workshop, including exposure modelling to better quantify environmental inputs and research on how pet owner behaviours influence environmental outcomes.

In 2025 the VMD launched a national pet owner survey, which closed in January 2026, to provide an indicative baseline of current pet owner product use and disposal practices. Additional behavioural research through the University of Plymouth will complement these findings.

These research outputs will support targeted communications, stewardship initiatives and future regulatory decision‑making.

When conducting a user risk assessment, before a veterinary medicine is authorised, both the hazards and the likely exposures to humans, including the children in a household, are considered. Data from both acute and chronic toxicology studies using animal models are used to identify the possible negative reactions that may be seen in humans if exposed. Several exposure scenarios are considered, including reasonable worst-case scenarios, leading to a conservative estimate of the actual risks to those that may come into contact with a veterinary medicine. A hazard may be identified, but if the exposure to the medicines is likely to be low, then this leads to minimal risk to the person. If risks are identified, they are listed on the product information database, alongside advice on how to minimise those risks. VMD collects data on adverse reactions reported to them and to pharmaceutical companies, once a product is on the market, and can update the risk profile and user warnings where these data indicate a concern.

The Veterinary Medicines Directorate (VMD) is undertaking a review of the AVM‑GSL status of veterinary medicines containing fipronil and imidacloprid, and further details on the review will be published in the coming weeks. A completion date cannot yet be provided as this is dependent on finalising the process and associated milestones.

The review will include a consultative process, drawing on evidence and input from all stakeholders. All decisions will be based on robust scientific assessment, with animal health and welfare remaining paramount throughout the review.

Environmental quality standards (EQS) are fundamental to the effective assessment and regulation of chemical impacts. This commitment has already been made in the roadmap produced by the Cross Governmental Pharmaceuticals in the Environment group.

The Government has set out its new vision for water through a White Paper published on 20 January 2026. The White Paper sets out once in a generation reforms that will transform the water system for good. It sets out how we will deliver on our promise to clean up our rivers, lakes and seas – not just for today, but for generations to come. We have committed to explore setting new ambitious overarching targets for the water environment. In the meantime, we continue to work towards our obligation to secure continuous improvement for the water environment.

The Veterinary Medicines Directorate (VMD) leads the cross‑government Pharmaceuticals in the Environment (PiE) Group and is taking forward a programme of work to address the presence of chemicals from pet flea and tick treatments in UK waterways. In response to detections of fipronil and imidacloprid above toxicity thresholds for aquatic invertebrates, the VMD published a roadmap setting out planned actions.

Progress includes holding the first PiE stakeholder workshop in Summer 2025, commissioning research on pet owner behaviours and exposure modelling, and working with environment agencies to improve monitoring data consistency. The VMD is also undertaking an evidence‑based review of the legal distribution categories for products containing these substances and contributing to international work to consider updates to environmental risk assessment approaches.

The Veterinary Medicines Directorate (VMD) is responsible for setting legal distribution categories for veterinary medicines and must balance animal health and welfare, public health, environmental protection and access to treatment. Many flea and tick products containing fipronil and imidacloprid are currently classified as AVM‑GSL, allowing supply without professional advice.

In light of environmental evidence, the VMD is undertaking an evidence‑based review of the distribution categories for these products. This includes considering whether requiring professional advice at the point of sale, through a minimum classification of NFA‑VPS, could help reduce environmental risk while maintaining access for pet owners.

Further details on this review will be available in early 2026. Any future regulatory decisions will follow a transparent, consultative process and will be based on robust scientific evidence, with animal welfare remaining paramount.

Veterinary Medicinal Products (VMPs) undergo a product-specific user risk assessment that considers all those that may come into contact with the medicine, including adults and children. This assessment considers the identified hazards of the medicine, the likely exposure to adults and children when VMPs are used as recommended and concludes on the likely risks to humans. The identified risks are mitigated using appropriate packaging and user safety warnings on the product information supplied with the medicines. Once authorised for marketing, pharmacovigilance reporting provides further data from use of these medicines in real-world situations, and these data are used to consider any changes required to reduce identified risks, such as updating the user safety warnings. If a concern with the current mitigations is identified, then the advice can be updated.

User risk assessments (URAs) are a core element of the authorisation process for veterinary medicinal products, and they include consideration of chronic human exposure in households where pets receive spot‑on treatments. The Veterinary Medicines Directorate conducts URAs in line with established international guidance, including the Committee for Veterinary Medicinal Products (CVMP) Guideline on user safety for pharmaceutical veterinary medicinal products (EMA/CVMP/543/03‑Rev.1) and the CVMP Guideline on user safety of topically administered veterinary medicinal products (EMA/CVMP/SWP/721059/2014).

These assessments follow a stepwise approach: hazard identification (drawing on extensive pharmacological and toxicological datasets, including for vulnerable sub‑populations), exposure assessment (covering short‑term direct and longer‑term indirect exposures), and risk characterisation using appropriate safety thresholds and conservative assumptions. For fipronil, the assessment considers relevant metabolites. Where indicated, risk mitigation measures are applied, such as user safety warnings, child‑resistant closures, and advice to minimise contact with the application site, reflected in the Summary of Product Characteristics and product literature (package leaflet).

The Pharmaceuticals in the Environment group, supported by the Veterinary Medicines Directorate, has put in place a roadmap for reducing exposure of these substances to water courses, with workstreams looking at several complementary activities. These include educating vets and the pet-owning public, investing in research to plug scientific evidence gaps, including routes to the environment and pet owner behavioural change, and reviewing the guidance for environmental risk assessments, which will all contribute to the desired aim.