26 Oct 2026
A House of Lords committee proposed the idea, but government officials said current evidence for it was not strong enough.
Allister Webb
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Calls for tougher rules on how long dogs treated with parasite medications should be prevented from bathing or entering surface waters have been rejected by Defra.
Peers had called for an extension of the restriction from the current four days to four weeks because of pollution concerns linked to the products.
But a newly published response from the department claimed there was insufficient evidence to support the idea and warned it could have broader consequences.
The measure was one of eight recommendations made by the House of Lords environment and climate change committee when its report, Paws for Concern: Pets, Parasites and Pollution, was published in August.
It argued the move was necessary after receiving testimony suggesting spot-on treatments can contaminate waterways up to 28 days after being applied.
In its response, Defra accepted most of the committee’s recommendations, including calls to improve training, fund further research, introduce more stringent environmental risk assessments and publish anonymised sales and usage data. It also stressed that work to review emerging exposure pathway evidence would continue but argued current advice, together with public education and awareness initiatives, “remains the most proportionate approach”, pending its outcome.
The department said it did not consider current analysis “sufficient to support a mandatory extension of bathing and swimming restrictions”.
It continued: “Existing studies are based on a relatively limited number of animals and rely on a range of assumptions regarding animal behaviour, environmental exposure, waterbody characteristics and environmental conditions that may not fully reflect real-world use.”
The document insisted any changes should be based on “a robust and scientifically validated” risk assessment framework and claimed the 28-day proposal represented “a significant extension of existing advice and could have wider implications” for both animal welfare and the use of those and other alternative products in practice.
It further warned that any new restrictions could risk both increased “regulatory complexity” and divergence in product availability between Great Britain and Northern Ireland, which may also impact manufacturers’ marketing decisions.
Committee chair Baroness Sheehan welcomed the Government’s response to most of the report but admitted the rejection of the 28-day proposal was “disappointing”.
She said: “Pet owners deserve accurate evidence-based guidance on the need for, and risks of, the existing and new chemicals that are being sold and the impact they are having on their pets, home and the environment. We look forward to raising this issue with the minister when we debate the report in the near future.”
Another area of potential dispute may lie in the committee’s call for tighter restrictions on the sale of parasite medications, preventing their distribution without “individualised advice” being applied.
Defra’s response said it would be inappropriate to “pre-judge” the findings of an ongoing VMD review of the issue. However, a summary of responses to a call for evidence it issued in the spring is expected to be published in the coming weeks.