Dogs water with pesticides even weeks after flea treatment

If your dog jumps in the nearest river, pond or lake that gets half a chance, Don Spot-On Treatments will use fleas and ticks, researchers say.

A study has shown that when dogs are submerged in water, their skin and fur can release the active ingredients that are harmful to aquatic wildlife and the animals that eat them – including birds – for up to 28 days after treatment.

“If your dog swims regularly, don’t treat it with spot-on,” says Rosemary Perkins at the University of Sussex, UK.

Since spot-on treatments we first introduced, they were wrongly believed to have no consequences for the wider environment. Only in 2011 did a European pharmaceutical paper suggest that animals be kept out of water for 48 hours afterwards, and this proposal was not based on any experience, Perkins says. “I definitely couldn’t find any supporting evidence for that. It’s just a thumb.”

She began to suspect that there was an after-end Fipronil, one of the pesticides used in spot-on treatments, in the rivers in the UK. “We found amazingly high levels,” says Perkins.

So her team used spot-on treatments containing either fibronil or a neonicotinoid called imidacoprid for 25 and 24 dogs, attent. After five, 14 or 28 days, the dogs were tight in water up to their shoulders in plastic bath for 5 minutes and the levels of pesticides in the water we are then measured.

The team found that even after 28 days, the ampesticide that came out of a single large dog in this timeframe would be enough to exceed safe levels if mixed in a 100-cubic meter body of water. That’s the amount of a pond a felt across, but even much larger bodies of water will exceed the safe boundaries if lots of treated dogs swim in them often, says Perkins.

She argues that regulators surround the world should change guidelines, but suspects this could take a long time if it happens at all. But dog owners can act now-they should only use spot-on treatments when needed, rather as a preventative, says Perkins as well as keeping dogs away from the water for at least one month after treatment. “The domestic help is that there is an element of risk if your dog swims at any time within it”.

There is now an alternative to spot-on treatments in the form of oral tablets, but Perkins says it is not clear if this is better. The active ingredients are long-la-la-la-la-la-lash chemicals that are excreted in faeces and can contaminate soil, she says. “We just have no idea what their influence is.”