Future proofing parasite control

By vet Freya Wood

Routine worming of horses is something that has been ingrained in equine management for decades, but recently there has been a push toward more testing - why is the advice changing so much?

Diagnostic-led worming is becoming increasingly more important as drug resistance develops, and we understand more about the environmental harm these drugs do. 

Faecal worm egg counts are something most horse owners are familiar with to look at numbers of parasite eggs being shed onto pasture, aiming to identify and treat high shedders to reduce pasture contamination and therefore the number of worms grazing horses ingest. 

Picking droppings up off pasture is an important adjunct to this. A faecal worm egg count reduction test once a year is also recommended to check the efficacy of the worming products used. 

Tapeworm testing is becoming more and more common. A saliva swab is performed by the owner for testing of the immune response to tapeworm. Reports of drug resistance in tapeworms are beginning to emerge in the UK and USA and therefore testing will be more important. 

The small redworm blood test has recently become further validated meaning as vets we can recommend this with more confidence. Traditionally a moxidectin treatment in the winter to manage encysted redworm is advocated, but in order to protect this drug, testing and targeted use is vital to protect this drug for the future. 

There is no one size fits all solution to worming in horses and a bespoke plan should be tailored to individual horses and yards and guided by a veterinary surgeon with an evidence-based approach. 

We have a responsibility to protect these drugs for the future to prevent disease in our horses and to reduce the impact we have on the environment by their use.