Dog flea treatment impacting rivers

Useful advice to prevent polluting rivers

They might be man’s best friend but the flea treatment you are using on your dog could be one that is wiping out the aquatic life in our rivers.

We all want to enjoy our rivers, which is great they are important blue spaces to value and get pleasure from; but for rivers to thrive we need to be mindful of the impacts we and are pets are having on them.
Fipronil is a broad use insecticide that is used in many flea treatments. It is already banned from agricultural use. The flea treatment products causing an issue are water soluble and stay on the dog’s fur for weeks.

In flea treatments it takes 24 -36 hours to kill the target pest (ticks and fleas) but the active ingredient has a long-time residual which can last up to 90 days!

Insecticides kill insects. A healthy river or stream should be heaving with insect and other invertebrate life. Often the presence of aquatic insect life is not seen, because the majority of their lives are spent in the riverbed gravels.
Mayfly larvae, caddis larvae, freshwater shrimp and many other tiny but vital creatures live sometimes for several years hidden away in the gravel, however they are extremely sensitive to pollution and do not stand a chance against a potent insecticide. 

An absence or lack of insects upsets the food web. 
These freshwater insects and invertebrates are an important food source for fish and birds, as well as being processors of organic detritus.For example, a shrimp gets eaten by a bullhead, that bullhead gets eaten by a kingfisher. These creatures are all linked.

There are non-toxic products worth trying, for example dimethicone.

Click the image below left for an article about this subject published November 2020 in The Guardian and below right for a scientific paper that looks at the subect more widely; washing dog bedding, washing dogs and a sewage treatment system that isn't designed to remove those chemicals from sewage before the 'clean' treated waste water is discharged into our rivers.


We know first hand from a pollution incident on the Kennet in 2013, caused by an insecticide getting into the river that it only takes a small quantity of insecticide to wipe out significant amounts of insect life.