Insecticides used to kill fleas are proving to be way too effective. The chemicals are poisoning English rivers and killing bugs they were never meant to encounter, according to a new University of Sussex study. The environmental damage extends to the birds and fish who depend on the poisoned bugs for food.
“Fipronil is one of the most commonly used flea products and recent studies have shown it degrades to compounds that are more toxic to most insects than fipronil itself,” said Rosemary Perkins, who led the study. “Our results are extremely concerning.”
The researchers identified fipronil in 99% of the samples they took from 20 rivers. In addition, they found a nerve agent called imidacloprid, which was temporarily banned in the EU in 2013 and then permanently so in 2018. This toxic pesticide ingredient is commonly used in farming in many parts of the world as well as being used for flea treatments.
Dave Goulson, one of the University of Sussex researchers, was shocked by the findings. “I couldn’t quite believe the pesticides were so prevalent. Our rivers are routinely and chronically contaminated with both of these chemicals.” He warned that using imidacloprid to treat one medium-sized dog for fleas contains enough pesticides to kill 60 million bees.
How are these pesticides moving from Fido to the Thames? Researchers found the highest pesticide concentration just downstream from water treatment plants, indicating that the urban areas were the culprits, not the farmers. They believe that when people bathe their pets, it flushes pesticides into sewers and then rivers. Dogs that swim in rivers could also be responsible.
If you’ve ever taken your pet to a veterinarian, it’s likely that the vet advised flea treatments. According to the American Kennel Club, the dangers of fleas go beyond itchy skin, with the top three possible consequences being flea allergy dermatitis, anemia and tapeworms. About 80% of the U.K.’s 11 million cats and 10 million dogs receive treatment, whether or not they have fleas. Some environmentalists are saying that the environmental damage of insecticides should be prioritized over the blanket use of flea remedies.
NRDC has some good recommendations for minimizing the environmental impact of flea treatment, including choosing oral treatments over flea collars, dosing for the correct weight of your pet, grooming your pets and cleaning your yard and garden in ways that will preempt pests to begin with. Read the organization’s full advice here.
Image via Joshua Choate