Navigating the Challenge of Rising Wormer Resistance in Horses


Professor Jacqui Matthews BVMS PhD FRSE FRCVS recently joined Dr Katie Williams (Dengie Technical & Product Development Manager) and Katie Reeve (Dengie Equine Nutritionist) to discuss recent updates on dealing with the threat of increasing anthelmintic resistance in horse parasites. If you missed the webinar, the recording can be found on our YouTube Channel or viewed below.

Professor Jacqui Matthews is an RCVS Recognised Specialist in Veterinary Parasitology and has been passionate about parasites for over 30 years. Her research has generated over 150 research papers and reviews, as well as some patents. In 2022, she moved to Austin Davis Biologics as Vet Science Director, supporting use of innovative diagnostics for evidence-based worm control to improve equine health.

The recent webinar discussed the threat of increasing wormer resistance in horse parasites and why drug resistance has developed, summarising the steps horse owners can take to try to avoid further wormer resistance. Jacqui also gave an overview of the management measures that can be taken to effectively reduce transmission of worms to horses from their environment, such as regular poo picking. Jacqui recommended using the various tests available, such as faecal egg counts, saliva and blood tests, to identify if the horse actually needs a worming treatment rather than blanket worming.

Austin Davis has recently launched a ‘What’s Your Worm Risk’ calculator, a free online tool designed to risk assess worm infections in horses based on a series of questions relating to transmission and control. Once the risk level is determined via the calculator, appropriate management, testing, and treatment steps can be recommended to minimise worm infection in the environment. These approaches break transmission cycles and ensure that monitoring tools, such as faecal egg counts and antibody tests, are used effectively to ensure that treatments are only given to those horses that genuinely need them. The risk of resistance is therefore reduced which helps maintain the long-term effectiveness of the available wormers.

Equine Nutritionist Katie Reeve also gave a presentation on factors influencing equine digestive health. “There were so many questions for Jackie and often relating to the constraints that livery yard owners impose on their clients. More has to be done to help spread the word about resistance to anthelmintics and so I was delighted we could host this webinar with Jacqui”.

For more information about gut health or for help and advice on all aspects of feeding call the Dengie Feedline: 01621 841188 or complete our Feed Advice Form.