Worm egg counts

Worm egg counts are an inexpensive, simple way to ensure that your horse is not carrying a large worm burden.  The process eliminates the need for regular blanket worming – making the worming experience better for your horse as well as your wallet!

All we need is a small sample of your horse’s droppings – a small handful is plenty. These need to be as fresh as possible and stored in a sealed container or strong plastic bag. The name of the owner and the horse should be clearly written on the container or bag in permanent marker, along with a contact number or email address. Then just pop them into the practice as soon as is convenient for you – If you can’t get the samples to us right away, it’s fine to refrigerate them for up to 24 hours.

At Valley Equine Lab, we use the McMaster flotation method for counting worm eggs. This method is great for picking up strongyle and ascarid eggs, and you will be given your results in eggs per gram (EPG). As a guide, we suggest taking the following action with certain results:

  • <200 EPG – negative or very low worm burden – no need to worm
  • 200-1200 EPG – moderate worm burden – suggest horses in this category are wormed
  • >1200 EPG – high worm burden – this level of worm burden will require a vet to discuss your worming programme and make changes/treat accordingly.

In a similar way, we use worm egg counts to determine resistance problems. We suggest a sample is submitted before a worming treatment is given, and again after treatment. High results before worming and low or negative results post-worming suggest that the treatment you are using is correct. Consistently high results before and after treatment suggest that you may be encountering a resistance problem in your yard, and a change in wormer may be needed. Your vet will be able to advise you on this.

Tapeworms produce large eggs which are not readily seen in floatation techniques such as the one listed above, and so it is advisable to test your horse twice yearly with a quick tapeworm ELISA blood test. We have connections with an external lab that performs these tests regularly, and you could have your results back within 3-4 working days. Prices start at £21.80 (excl. VAT and postage) per horse.