Toxic levels of two ingredients of popular pet flea treatments have been found in UK waterways. Pet owners can take measures to avoid these chemicals entering waterways or may wish to investigate alternative products for the pets. Worming products may also contaminate the environment if faeces are not collected and disposed of considerately.
Toxic flea treatments found in waterways.
A report published last year showed that the popular flea treatment ingredient Fipronil and its metabolites were found in 98% of freshwater samples with most samples having 5 times the safety threshold. Another flea treatment, imidacloprid, was found in 66% of samples, with toxicity levels exceeded in 35% of cases.
The highest levels of contamination were found downstream of water treatment works which suggest the chemicals are entering the water from household drains rather than swimming in rivers. Sadly, these chemicals and their breakdown products are highly toxic to all insects and water invertebrates.
What can pet owners do to limit the effect on the environment while keeping their pets flea free?
Pet owners should always follow the instructions for applying topical parasiticides safely. Topical treatments may not be advisable for dogs who swim in streams, lakes, and rivers or who are bathed regularly. Packaging must be disposed of carefully in household waste.
Oral flea and tick treatments are less likely to wash into waterways but can still contaminate the environment if pet faeces are not picked up and disposed of. There are both short and long-acting oral treatments and some also prevent intestinal worms.
Are wormers a problem in the environment?
Some scientists also think that pet worming treatments may cause environmental damage as they can kill invertebrates in the soil. Picking up and disposing of faeces in landfill waste may reduce the impact on sensitive environments. Cats should be encouraged to use indoor litter trays.
Do we need to treat for fleas and worms regularly?
Regular parasite treatments are recommended by vets for animal and human health reasons. Just a single tick bite could infect a dog or human with Lyme’s Disease. Toxocara can cause blindness and liver damage in children, yet few dogs and cats are wormed frequently enough to prevent the eggs being shed into the environment.
Flea infestations have become a year-round problem with our arm wet winters and central heating. It is estimated that by the time one flea is seen on a pet there will already be hundreds more eggs in the home! Fleas and other skin parasites can bite humans as well as pets and can cause painful reactions.
Are there alternatives to chemical parasite treatments?
It is possible to reduce parasiticide use by regular monitoring of pets. Weekly combing can detect fleas and flea dirt, and dogs should be checked after every walk for ticks. Faecal samples can be sent to a laboratory every 3 months to check for worm eggs, but ensure lungworm is included.
There are several herbal supplements which claim to control internal parasites, but they should be used alongside faecal egg counts. Essential oil-based flea sprays can be toxic to cats and may also affect non-target insects.
Diatomaceous Earth can be effective for external parasites but must not be inhaled and needs applying frequently.