A faecal worm egg count (FWEC) is a simple lab test that shows how many worm eggs your horse is passing. Testing first means you can treat the horses that need it, rather than worming every horse on a routine. It also helps slow the spread of wormer resistance. This guide walks you through doing the test at home with a postal kit.
What you need
Your Vet-Lab equine worm count kit has what you need to collect and send a sample, including a freepost return envelope. You will also need a pen to label the sample, and a clean bucket or bag if you want to keep it cool until posting.
Step 1: Choose your day
Pick a day when you can collect a fresh sample and post it promptly. Avoid collecting just before a weekend or bank holiday, because samples should reach the lab as fresh as possible.
Step 2: Collect a fresh sample
Put on the glove and pick up a small amount of fresh dung, ideally from several different droppings, soon after it has been passed. Fresh means still warm and moist. Avoid dung that has been lying in the field for a long time, as eggs can hatch or dry out.
Step 3: Fill the silver pouch and label it
Fill the silver pouch as instructed in your kit and seal it tightly. Then write the animal’s name and tick the species box on the label of the silver pouch. Fill out your details on the voucher, making sure you add your order number. You can find it in your order confirmation email (for example: New Order: #3001). If you are testing more than one horse, use a separate silver pouch for each and take care not to mix them up.
Step 4: Post it promptly
Place the sample in the return envelope and post it as soon as you can. If you cannot post it straight away, keep it somewhere cool, not frozen, and send it the next day.
Step 5: Read your result
Your result is reported as eggs per gram (EPG). As a rough guide, many people treat counts under about 250 EPG as low, counts of roughly 250 to 1200 as moderate, and counts over about 1200 as high. Thresholds vary between vets and yards, so use these figures as a starting point and talk to your vet or a qualified adviser about what to do for your horse.
If you do treat, a follow-up test around 10 to 14 days later can show whether the wormer worked. Vet-Lab’s wormer resistance test kit, also in our equine shop, is designed for this.
What a worm egg count cannot show
- It counts eggs, so it does not detect immature or encysted worms in the gut wall. A low count does not rule out a worm burden.
- It is not a reliable test for tapeworm, bots or pinworm. Talk to your vet if you are concerned about these.
You can read more about the worms that affect horses in our horse parasites guide.
How often should I test?
Many owners test several times through the grazing season, then adjust based on their horse’s results and their vet’s advice. Horses vary a lot, so some consistently have low counts while others need closer monitoring.
Free downloads
Print our free sampling checklist, yard record sheet, results guide and seasonal testing calendar to keep with your kit.
Ready to test?
Order your equine worm count kit and only worm when your horse needs it.