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November 10th, 2023

Is Flea Treatment Polluting The Environment?

By Fiorella Castro

A month ago, I had the opportunity to work with Dr Peter Caldwell in South Africa, where we spent some time talking about deworming. For those of you who don’t know who Dr Caldwell is, he is a world-renowned wildlife veterinary surgeon in South Africa and has been involved in a lot of research work. 

During our conversation, we talked about how some dewormers were causing the death of bees, environmental pollutants and how some dewormers have even had an environmental impact on green spaces and rivers around the world. 

So, I was curious to investigate a little more. We, as veterinarians, have a very important role in animal, human and environmental health, and because of this we should be aware of these sorts of issues. 

The idea of this blog is to raise awareness of the use of dewormers without compromising the health of our pets. We know the importance of deworming our pets from time to time to protect them from diseases and parasites, and this should continue to be done, but are we aware of whether we are unwittingly contributing to environmental damage?

group photoMany of the products we use for deworming tend to be broad-spectrum, to combat different types of parasites, and although the use of broad-spectrum products has been great, it has also meant that some of them can be damaging to the environment. 

A few years ago, it was discovered that there was contamination in some rivers in the UK due to the use of chemical flea treatment, mainly imidacloprid. In previous studies, it had already been questioned due to its effect on bee populations. 

Many of our customers may wonder how products given to their pets can affect the environment. There are many ways in which products can affect the environment, for example, where the dog leaves the house, does its needs and they are left on the ground or if the dog has a lifestyle where they spend lots of time in the water, chemicals are left in small quantities in rivers. When looking at how many animals are in a single country, even if chemicals are left in the environment in small concentrations, there will still be significant impact. 

In a recent PDSA study they collected data, reporting 10.2 million dogs in the UK and 11.1 million cats in the UK. If a large part of this population is receiving dewormers frequently, the irresponsible use of drugs can generate a significant impact on different populations important for the environmental balance. 

Research has found that imidacloprid and fipronil are highly toxic in small amounts to invertebrates. As a result, these species have been dying out. Many of them were part of the food chain off fish and birds, affecting those ecosystems as well. 

Although some countries have taken steps to ban these products, many have not made a start, so some advice I can give to colleagues around the world are:  

  • Be aware of what we are giving to our patients. 

  • Try to stop using broad-spectrum dewormers. 

  • Research which types of products do not pose a risk to the environment and which ones are available in your market.  

  • Explain to pet owners that pets living indoors are less likely to contract parasites. 

  • Know the ‘hot spot areas’ of different parasites in the country to know what to treat with. 

  • Instead of dosing every month or every three months with a chemical, recommend owners to do a worm egg count to see if they need treatment.  

  • In winter, as it is a low season, certain products can be reduced, and more specific treatments can be given. 

Leave your thoughts on this subject in the comments and what other things can we start doing to reduce environmental damage? 

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