Faecal sampling - test before you treat

13th June 2018 

Dr Rosie Naylor BVetMed MVetMed DipACVIM PhD MRCVS RCVS Specialist in Equine Internal Medicine, Technical Product Manager - Equine, Virbac UK

The 2017 National Equine Health Survey revealed that 37% of horse owners never carry out faecal egg counts. Don’t be one of them! Faecal egg counts are an important way of identifying the 15-20% of horses that need worming. By performing faecal egg counts it is possible to reduce wormer use by up to 82%. This protects the drugs for use in the future and can also save money!



Top Tips from Virbac 3D Worming for collecting a faceal sample from your horse

  1. Identify a fresh dropping
  2. Collect several samples from different faecal balls throughout the dropping
  3. Place in a sample pot or freezer bag with no air inside
  4. Label clearly with the horse’s name
  5. Take the samples straight to the lab to be analysed. If this isn’t possible place the sample in the fridge overnight to prevent the eggs from hatching.


Generally only horses with a faecal egg count greater than 200 eggs per gram are treated. During the summer grazing months treatment with wormers containing ivermectin, pyrantel or fenbendazole are recommended. Most experts recommend not using moxidectin at this time of year, to preserve its effectiveness against encysted redworm, treated during winter. Your vet or SQP will be able to help select the most appropriate treatment.


Have an accurate idea of your horse’s weight, and don’t forget this can change significantly through the grazing season! For help on using a weight tape watch the ‘how to’ video at www.3dworming.co.uk. Then make sure there is enough drug in your wormer treatment to treat your horse’s bodyweight. Syringes can contain 600kg or 700 kg doses. For larger horses tablets are available that treat up to 800kg.


Avoid spit out as this will result in under-dosing. Not only does under-dosing mean that effective treatment is unlikely, it also increases the chance of resistance developing. For horse’s that are difficult to worm with a syringe, tablets are available. Don’t forget, wormer drugs can be poisonous to other animals so be sure to dispose of your used syringes carefully!

Brought to you by Virbac, the manufacturer of Equimax® and Eraquell®.