Should we be routinely de-worming and de-fleaing our pets?

The debate about regular de-worming has been a hot one in the horse world for several years now. Traditionally, it was seen as best practice to give horses de-worming treatments, as a matter of course, at least twice a year.

The British Horse Society (BHS) now recommends a different, test-led approach.

The BHS likens the continued frequent use of de-worming chemicals to the unnecessary use of antibiotics which, in both cases, is leading to drug resistance.

There is now evidence of resistance to all classes of horse de-worming drugs available in Great Britain, and there is no prospect of new drugs being developed in the future.

This situation could be potentially catastrophic, and lead to horses carrying heavy worm burdens that can lead to colic and anaemia – life-threatening conditions.

Furthermore, de-worming drugs are not selective for horse worms and will kill a range of invertebrates if they come into contact with them through horse faeces left in fields.

Some of the most common chemicals used to de-worm horses are highly toxic to invertebrates such as dung beetles and most forms of aquatic life, meaning they pose a real threat to our ecosystems.

The BHS recommends that horse owners use faecal worm egg count test kits, which can be purchased relatively cheaply online or obtained through vets.

An annual saliva test should also be undertaken to monitor tapeworms. And, of course, prevention is better than cure and the BHS emphasises the importance of good pasture management – basically, regular poo-picking.

But what’s this got to do with dogs and cats?

Cats, in particular, like to bury their faeces in the soil (usually a neighbour’s garden!) and, as with horses, this means that de-worming chemicals are entering the ecosystem. And dog owners need to think twice before they allow their dogs to poo in the long grass and not scoop up afterwards.

A recent survey by Imperial College London has shown how anti-flea and tick chemicals, routinely used on our dogs and cats, are posing a real threat to marine life.

Research undertaken in the South West of England on seawater, sea weed and shellfish has shown the presence of more than 100 unique pharmaceuticals, pesticides and illegal drugs – basically, chemical pollution.

An insecticide regularly used on domestic pets in flea and tick medication, Imidaclopid, was the highest risk pollutant according to the researchers, who are asking us all to reassess the practice of blanket preventative treatment of our dogs and cats to help bring down the risk.

The insecticide enters the water in a range of ways, including dogs swimming shortly after a ‘spot-on’ application has been administered, or when owners wash their hands after application.

The British Veterinary Association recommends that vets and pet-owners take a risk-based approach to prescribing flea and tick treatments, dependent on an animal’s exposure to parasites (implicitly criticising some ‘pet health club’ schemes that take a blanket approach).

So, for example, a cat that routinely hunts outdoors is more likely to pick up parasites than a more sedentary or indoor cat.

Owners should routinely check their pets’ fur for signs of fleas or ticks, and ensure bedding is washed regularly.

This same risk-based approach should also be taken when it comes to administering de-worming treatments to dogs and cats – again, these are often routinely administered as part of ‘pet health clubs’.

It is also important for owners to dispose of unwanted medicines and packaging carefully to minimise environmental contamination.