Vet medicine is leaching toxic chemicals into rivers

“Entire ecosystem” is being disrupted as insect larvae – essential food sources for fish, birds, and bats – are vulnerable to the toxic effects of veterinary chemicals
16 November 2023 , By Kerry Taylor-Smith

Chemicals are thought to have polluted rivers via household wastewater contaminated by washing pets, and by allowing treated dogs to swim in waterways

Pesticides in veterinary medicines are leaching into rivers at concentrations exceeding accepted safe limits for wildlife, prompting environmental and veterinary organisations to urge the government to ban their use.

Known collectively as parasiticides, these chemicals are too environmentally damaging to be used as pesticides on crops but are ingredients in numerous tick, flea and worm medicines.

Analysis of Environment Agency data by The Rivers Trust and Wildlife and Countryside Link revealed three of these toxic chemicals are present in 109 of 283 of England’s rivers: fipronil at 105 sites, in two cases at 1,000 times accepted safe limits; imidacloprid at 22 sites; and permethrin at four sites.

The chemicals are likely to have filtered in via contaminated household wastewater from washing treated pets and bedding, urinary and faecal excretions, and allowing treated dogs to swim in rivers.

"It’s a shocking reality that the chemicals in our pets' tick, flea, and worm treatments are now polluting our rivers, with detrimental effects on our aquatic ecosystems.,” said Rob Collins, The Rivers Trust Director of Policy and Science.

Insect larvae, like mayflies and dragonflies, are particularly vulnerable to the toxic effects of veterinary chemicals and serve as essential food sources for fish, birds, and bats, Collins added: “When these pesticides enter our rivers, they disrupt the balance of the entire ecosystem, causing ripple effects that impact the wider environment."

“Where alternatives exist, which they absolutely do in the case of pet medicines, chemicals known to be harming wildlife should be taken off the market.”

Josie Cohen, Head of Policy and Campaigns, Pesticide Action Network UK said, “It simply makes no sense to block these chemicals from being used on crops in order to protect the environment, while allowing them to be routinely applied by millions of pet owners every month. Where alternatives exist, which they absolutely do in the case of pet medicines, chemicals known to be harming wildlife should be taken off the market.”

Richard Benwell, CEO of Wildlife and Countryside Link added: “Giving pets the highest standard of care need not come at the expense of nature, but these findings suggest that too many insecticides and other toxic chemicals are still ending up in our rivers.”

Vets are also concerned about the environmental impact of veterinary medicines, with bodies like the Progressive Vets Association (PVA) supporting a ban on parasiticides “to reverse wildlife declines”.

“Parasiticides are important products which play a key role in preventing and treating parasites in animals, which if left unaddressed can lead to bigger health and welfare issues,” added Anna Judson, President, British Veterinary Association (BVA). “But it's important they are used responsibly to minimise the impact on the environment and so we encourage vets to apply a risk-based approach to using these products, and to discuss with clients how to use them responsibly and safely.”

A Veterinary Medicines Directorate spokesperson said: “When authorising veterinary medicines, we take into account both parasite control as well as environmental risks. In this instance, the medicine plays a vital role in treating fleas and ticks, which can lead to harmful diseases in pets and present risks to humans. We will continue to take a balanced approach on veterinary medicines and have set up a group of experts to research how we can best reduce the impacts of pharmaceuticals on the environment.”

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