Faecal Worm Egg Counts

The heavy use of wormers over the past 20 years has unfortunately led to a significant amount of worm resistance within the equine population. This means that some wormers are no longer effective at eliminating worm burdens in some horses. These problems can be overcome relatively easily by monitoring the faecal worm egg count (FWEC) of all horses on a yard at regular intervals. This ensures only those individuals with a significant worm burden are treated using appropriate wormers at appropriate times, thereby reducing the problem of resistance.

The FWEC is a relatively simple procedure that only requires a small amount of input from the horse owner. To do this we need you to provide a small amount of your horse’s droppings, approximately 10g or a heaped teaspoon size (selected from more than one nugget). The sample should be as fresh as possible, ideally being delivered to the clinic on the day of collection. Alternatively, samples can be sent by post using one of our free-post sample kits. Click HERE to request your free kit(s). Samples can also be collected into a clearly labelled sealable container, such as a plastic sandwich bag and brought in within 24 hours along with a completed request form.

Click FWEC Guidance Notes for a simple guide to collecting a faecal worm egg count sample.

To download a FWEC request form (if you are not using one of our free kits) which is required for sample submission: click FWEC Postal Form (1-4) 2022 for the submission form for 4 samples or less and click FWEC Postal Form (yard) 2022 for the submmission form for 5 samples or more.

For those samples coming from a larger yards, it helps to call our team in advance on 01622 813 700.

Following microscopic analysis of each sample individually, we aim to contact you with your results within 48 hours. This gives your vet the opportunity to advise you on any further treatment, considering our knowledge of your horse. This also gives you the opportunity to ask any questions, a service of which is all included in the lab fee. By running worm egg count tests 10-14 days after worming, we can see how effective the wormer has been at eradicating the worms. This is know as the ‘faecal worm egg count reduction test’.

Unfortunately tapeworms are not detected by routine worm egg counts, so a tapeworm blood test or saliva test should be performed at least once a year. Often with the results showing no treatment is required.

Pinworms can sometimes be hard to identify and may need a specific test.

Unfortunately there is no available diagnostic test to determine if horses are carrying large burdens of ‘encysted’ (immature) small strongyles. Therefore, it is advisable that all young horses less than 5 years old or others at particular risk are treated for this type of worm once a year. Our vets can advise you further if you have any questions.

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