There are calls for a more targeted use of pet parasite treatments amid concerns of the chemicals’ impact in the environment.

The UK parliament’s Environment and Climate Change Committee has published its report, ‘Paws for concern: pets, parasites and pollution’, which calls for a ban on the general sale of off-the-shelf and unchecked online pet parasite treatments. The Committee argued for a recalibration of how the UK approaches pet parasite medications in order to protect both companion animals and the natural environment.

The call came after the inquiry raised concerns over the use of fipronil and imidacloprid in the treatments. The inquiry sought to understand distribution pathways, and the impact of PPM use and non-use on biodiversity and human health. It also covered current regulation, monitoring, and the potential implications for pets and pet owners of changing application practices.

The Environment and Climate Change Committee is calling on the Government to:

• Collate and publish anonymised data on PPM product sales and usage habits;
• Establish the true scale of pollution resulting from all PPMs;
• Extend the Phase II Environmental Risk Assessments to all PPMs;
• Review the relationship between the VMD, industry and VICH to remove the risk, or perceived risk, of regulatory capture;
• Establish funding schemes with UKRI to address the substantial evidence gaps relating to the use of PPMs;
• Introduce an interim risk-based PPM regime which restricts access to all parasiticides and requires that they are only sold alongside individualised advice and assessment; and,
• Update the VMD’s guidance on product packaging to extend the period where pets should not be allowed to bathe from four days to 28 days after the application of spot-on treatments.

Baroness Sheehan, Chair of the Environment and Climate Change Committee, said: “Our report raises serious questions and concerns about the environmental risks of pet flea and tick treatments as well as how they are sold to pet owners. Their over-use on household pets is the equivalent of using a sledgehammer to crack a nut.

The lack of scientific evidence and data, poor customer guidance and the relationship between the pet medication suppliers and regulators appear as murky as the waterways these flea treatments are polluting.

Pet owners deserve accurate evidence-based guidance on the need for, and risks of, the existing and new chemicals which are being prescribed and the impact they are having on their pets, home and the environment.”

Professor Guy Woodward, professor of Ecology, Imperial College London said: “We know from many laboratory studies that these chemicals can induce negative ecotoxicological impacts on a range of biological processes affecting growth, development and reproductive in many species, and invertebrates, which form the core of many freshwater food webs, are particularly sensitive.

“Imidacloprid and fipronil have already been banned from outdoor agricultural use in the EU and UK, since 2018 and 2017, respectively, based largely on the potential environmental threat they pose to pollinators, such as honeybees.  They have also been correlated with large-scale declines of European farmland bird populations.  Concerns now are being raised about the same chemicals being used in pet parasite medicines (PPMs) leaking into the environment and their potential to disrupt freshwater ecosystems – through both direct toxic effects on individual organisms and indirectly, by altering interactions within the food web (e.g., eroding food resources for fishes).

“Some of our recent modelling work has shown that down-the-drain “wash off” of pet parasiticides is likely the major route of contamination in freshwaters, and the concentrations we see in the wild overlap with those of lab studies that show clear ecotoxicological effects on a range of freshwater species.

“These chemicals are very effective at killing invertebrates at even very low doses – that is what they are designed to do, after all – but problems can arise when they leak out into the wider environment.  Plenty of ecotoxicological lab studies have demonstrated a wide range of impacts on model test organisms, and correlational field data have also associated them with declines in ecologically important species, such as dragonflies and mayflies, with suggestions of knock-on consequences for other species they interact with in the food web, such as fishes.

“Lab studies have shown that these chemicals can have negative impacts on growth, reproduction and survival of individual organisms across a range of species and at concentrations that we are seeing in the field.”