Pet flea treatment linked to rise in bird deaths, Sussex study finds

  • ITV News Meridian's James Dunham spoke to researchers at University of Sussex about their findings.

Flea treatment used on cats and dogs have been proven to be harmful to garden birds, new research has found.

The study by University of Sussex showed that birds which line their nests with fur, including blue tits and great tits, are most at risk.

Researchers collected 103 nests which were lined with fur and tests detected 17 out of the 20 insecticides screened within them.

They found clear evidence that high levels of harmful chemicals found in flea treated fur, used to make birds nests, leads to higher numbers of unhatched eggs or dead chicks.

Researchers say chemicals found in fur treatment led to to higher numbers of unhatched eggs. Credit: University of Sussex

Scientists have partnered with SongBird Survival to call on the government to reassess the environmental risks of pesticides in pet medicines.

Chemicals, such as fipronil and imidacloprid, are banned in the European Union for agricultural and plant protection purposes, however are used in treatments for pets, in the United Kingdom.

Of the 103 nests collected, 100% of nests contained fipronil and 89% contained imidacloprid.

  • Cannelle Tassin de Montaigu said the findings are "concerning."

Cannelle Tassin de Montaigu, research and associate fellow at the University of Sussex, said: “No nest was free from insecticides in our study, and this significant presence of harmful chemicals could be having devastating consequences on the UK’s bird populations."

“Our research shows that based on the chemicals detected, veterinary flea and tick drugs are the most likely source of contamination."

"We undertook our research when it was safe to do so at the end of the breeding season, so the problem could in fact be much worse.”

Birds like Blue Titis and Great Tits, which line their nests with fur, are at greater risk. Credit: University of Sussex

Researchers say the chemicals are frequently applied to pets and livestock as flea-treatment, in the form of shampoos, spot-on treatments, and sprays.

With the population of cats (10.9 million), dogs (10 million) and livestock (163.1 million) in the UK alone, there is a substantial risk for these treatments to enter the environment.

The British Veterinary Association recommends that vets should avoid blanket year-round flea and tick treatment policies and instead suggest individual vets to have informed discussions with their clients to risk-assess when these treatments are needed.

Previous research has shown that 74% of woodland bird species in central Europe line their nests with fur. Credit: Songbird Survival

Sue Morgan, Chief Executive of SongBird Survival said: “We are a nation of pet lovers and bird lovers, and it is extremely concerning to see the alarming levels of toxic pesticides in bird nests from veterinary drugs.

"Pet owners will be upset to hear that in trying to do the right thing to support their pets with fleas and ticks, they could be harming our ecosystem, resulting in dead newborn chicks and unhatched eggs.

"As pet owners, we need to have confidence that we are keeping our pets well, without devastating impacts on our wildlife.

“Our UK songbirds are in crisis. More than half of our UK songbirds are threatened or already in decline, which is why this latest research shows the importance of taking action as soon as possible.

"We want the government to undertake a more comprehensive environmental risk assessment of veterinary drugs.”

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