Calls to ban ‘toxic’ pet flea treatments that harm UK wildlife and environment

Over-the-counter treatments for cats and dogs contain chemicals that are banned in pesticides and pollute waterways

Over-the-counter flea treatment for cats and dogs should be banned as millions of hazardous chemicals are unnecessarily applied to UK pets each year, a parliamentary report has concluded.

Cats and dogs are widely treated with topical, or “spot on”, treatments that include insecticides to prevent fleas. Vets often recommend regular treatments as a preventive measure, even when the animals do not have fleas.

Two of the most frequently used chemicals in pet flea and tick treatments – imidacloprid and fipronil – are banned for use in pesticides in the EU and UK due to their severe toxicity to fish, invertebrates, bees and pollinators. By their very nature, these chemicals are designed to kill invertebrates at low doses.

A study found songbirds were using dog and cat fur contaminated with the treatments to create their nests . The scientists found a higher number of unhatched eggs or dead chicks in nests where there was a higher incidence of the chemicals.

It was assumed there was a low risk of these chemicals entering the environment, but recent research has suggested otherwise. A report published on Wednesday by the House of Lords environment and climate change committee found these chemicals are transferring to the natural environment, potentially causing widespread damage to ecosystems.

Researchers at Cardiff University found imidacloprid and fipronil in almost half of all samples across nine Welsh rivers. The Environment Agency said in its written evidence to the committee that even very small amounts of these two chemicals can cause environmental harm.

Guy Woodward, a professor of ecology at Imperial College London, told the committee that two sugar cubes of the concentrated active ingredient imidacloprid would be enough to exceed the predicted no-effect concentration in about 400 Olympic-sized swimming pools.

The committee also found that there was “worryingly insufficient evidence” to assess whether these chemicals were harmful to human health. Studies have found that fipronil and imidacloprid can impact foetal development and cause thyroid disruption.

Researchers at Imperial said the breakdown products can be “an entire order of magnitude more toxic” than the chemicals themselves. The Wildlife Trust said some of these chemicals break down to the most toxic Pfas forever chemicals.

The committee is calling on the government to act to reduce the routine use of these chemicals and ensure individualised advice is provided that takes into account the lifestyle, location and risk factors of the animal and those they live with.

The committee recommended a ban on sales of the topical treatments in pet shops or online. Pet owners would still be able to get preventative treatment prescribed by a vet.

The Wildlife Trusts has gone even further and is calling for a total ban of five of the most widely used chemicals.

The committee also raised concerns that the pet pharmaceuticals industry is “very involved” in establishing the regulatory processes for controlling these medicines. Rosemary Perkins, a veterinary surgeon, said there was a “fundamental problems with independence.

Shas Sheehan, the chair of the committee, said the relationship between the pet medication suppliers and regulators appeared as “murky as the waterways these flea treatments are polluting”.

She said the overuse of these medicines was the “equivalent of using a sledgehammer to crack a nut”.

The British Veterinary Association, which represents 19,000 UK vets, welcomed the committee’s findings. Elizabeth Mullineaux, a senior vice president at the BVA, told the committee: “It’s important pet owners have access to professional, tailored, veterinary advice on how to use these treatments appropriately, responsibly and safely when purchasing these products.”

A spokesperson for the Veterinary Medicines Directorate, the independent regulator, said: “We recognise that while pet parasite treatments play an important role in protecting pets and people from parasites and the diseases they carry, they are entering our watercourses which could be contributing to wider environmental impacts.

“That’s why we have consulted on this issue to help us maintain appropriate market availability of these substances while also protecting wildlife and the environment.”

A government spokesperson said: “While these treatments play a vital role in public and pet health against fleas and ticks, it is right that we assess the availability of these treatments to ensure correct usage by owners.”

It’s Invertebrate of the Year again ! Every day from 3-12 August, we will be profiling one of the thousands of amazing invertebrates that our readers have nominated, and when you have heard about all of them, we will open the voting so you can choose your favourites. Don’t hesitate to get in touch with thoughts and ideas. Email us at environment.desk@theguardian.com with Invertebrate in the subject line.