Veterinary Medicines: FAQs

As a pet owner, what can I do?

There are many alternative treatments and preventative measures available for pet owners that do not rely on imidacloprid and fipronil-based tick and flea treatments.

Seek advice from your vet about alternative treatments, ways to be more vigilant and reactive to parasites and how to reassess the risk they pose to your pets throughout the year depending on various factors.

If you treat your dog with pesticides, it is advisable not to let your dog swim for a month after the last treatment, based on evidence that shows the long-lasting negative effects of these pesticides on freshwater invertebrates.

Are oral medicines better than topical?

Much like topical flea and tick treatments, oral medications have undergone low levels of scrutiny for their presence and risk to the environment. More research is required before we can understand how much or little risk they pose.

As with topical treatments, you should discuss with your veterinarian the best treatment options for your pet.

For more information, check out the section entitled ‘Other chemicals used as veterinary pesticides’ on page 31-33 of the report.

What about medicines that don’t use fipronil and imidacloprid?

There are many pesticides used in tick and flea treatments. Our report focuses on imidacloprid and fipronil because they are the most commonly used and because there is overwhelming evidence spanning twenty five years demonstrating their presence and risk to freshwater invertebrates. Also, because these pesticides have been banned for outdoor agricultural use, there is a very clear justification for the government to address these pesticides.

There is a growing body of research looking into the other pesticides used in veterinary medicines highlighting the broader scope of the risks freshwater invertebrates face. It is essential that the government looks at alternatives and treat them to the same scrutiny. For more information, check out the section entitled ‘Other chemicals used as veterinary pesticides’ on page 31-33 of the report.

Do these pesticides only effect freshwater invertebrates?

These pesticides pose risks to wider ecosystems and terrestrial species, directly and indirectly. Other eNGOs have been examining wider issues caused by pesticides used in tick and flea treatments. To see what Wildfish has looked at, you can read their report here, and for Songbird Survival, you can read their recent blog on the topic here and look out for more information from both these, and other, eNGOs in the near future.

Why are these chemicals allowed to be used in veterinary medicines?

These chemicals are approved through a different regulatory regime to pesticides used in agriculture and are often effectively authorised indefinitely.

The approval process is insufficient to consider environmental harm and only test against a small number, of species, such as the water flea Daphnia magna

Furthermore, current environmental monitoring remains piecemeal and inadequate to properly assess the impact they are having.

For more information, check out the section entitled, ‘Existing industry recommendations and risk assessments’ on page 28 of the Report.

What about other veterinary medicines such as wormers, do they harm the environment?

Undoubtably most of the attention and research of the impact of veterinary medicines in the environment has looked at topical spot-on treatments for ticks and fleas. Consideration for a wider range of veterinary medicines, including wormers, has received less attention and lacks awareness, however a growing body of evidence is pointing to the environmental impacts of other medicines.

For example, studies have found that many worming treatments for pets and livestock have harmful effects on soil biota.

Buglife’s veterinary medicines campaign will grow and evolve and consider the evidence of different medicines.

As a pet owner, what can I do about wormers and other medicines that might harm the environment?

As with flea and tick treatments, the best action is to speak to your vet about alternative, less harmful treatments.

As a concerned member of the public, what can I do to engage with my MP?

You can send our report to your MP. Find your MP’s contact details here.

You can also ask your MP to sign something called an Early Day Motion (follow our step-by-step-guide and use our suggested template)

Veterinary Medicine Pesticides and Legislation

Both fipronil and imidacloprid are not currently routinely monitored or assessed by government regulators and their continued use in flea treatments undermines the purpose of their ban for agricultural use

In July 2025, the UK Government announced a roadmap to address the presence of fipronil and imidacloprid in waterways, focusing on topical flea treatments for pets. However, our analysis indicates that the roadmap is limited, and implementation is slow, which does not align with the urgent need to raise public awareness and prevent these substances causing further environmental harm.

At Buglife, we are committed to raising awareness about this issue with the public, industry and decision makers in order to better protect freshwater invertebrates.