What is a FEC?

Faecal Egg Counts, also known as FEC, WEC or EPG count assesses the worm burden within an animal. A FEC does what it says on the tin – a technician will look at the faeces and literally count the number of eggs in a set amount of the faeces. This is then taken as a representative for the burden of the animal.

Results are typically presented in EPG or eggs per gram, allowing you to compare animals at the same time and also track an animal’s burden over time. This technique can be used on practically any animal, although laboratories will have more familiarity with the parasite eggs typically present within the species they most commonly test. These would likely be sheep, cows, poultry, horses, dogs and cats etc. 

Why do I need a FEC?

FEC are an invaluable tool for farmers and vets alike. Firstly, they enable you to assess a parasite burden for any animal, or herd/flock prior to any treatment. This can allow you to tailor any treatment necessary to the specific parasite and at the same time ensure resistance does not become an issue. It also means you can perform a second check with a Worm Egg Count Reduction Test, enabling you to see how effective the treatment has been on the parasite.

FECs are great because they can give you an insight into the health status of an animal without being invasive. They are a cheap, easy and quick way to ensure healthy animals. FECs can be a great tool for both farmers and vets – farmers can use these to check on animals of concern or as part of a general monitoring program. They can then call the vet if they receive any results that are a cause for concern. Similarly, vets can make use of these tests during routine visits but also if they have suspicion of high parasite burdens within patients. 

It may be worth thinking about implementing FECs as part or you general husbandry practice, whether or not you typically use treatments like anthelmintics (wormers). These don’t always work perfectly, so it’s best to double check!

We can also provide a Pasture Larval Count which is similar to a FEC but instead it samples the pasture you intend to/are keeping animals on. You may want to do this before letting any naïve animals onto it. See here for how to proceed with a Pasture Larval Count. 

How do RRL do FECs?

Some of the worm eggs we might see when we do an FEC.
Some of the worm eggs we might see when we do an FEC.

There are a few techniques involving making the eggs float, spinning the sample in a centrifuge and counting the eggs using a special McMasters chamber, but the basic premise involves taking a measured amount of faeces and analysing this under the microscope. The lab technician will count the number of eggs found, speciate them, and calculate the burden in eggs per gram (EPG) for the sample. This can be performed on individual or composite samples, where multiple samples have been taken from a flock or herd. These are then mixed together at the laboratory so that the result is representative of an average of the herd.

What do I need to do?

It’s easy! All you need to do is take a sample of faeces from the animal(s) you would like tested. Please ensure the sample is definitely from the animal in question. You could do this by cornering them and wait to collect their faeces, or by watching them closely before collection. Make sure to send samples as fresh as possible to us. For instructions on how to do this, visit our services page here.

What does my FEC mean?

If you send in a sample for testing, you will be provided with an EPG count and the species found within your sample. Using these results, you can then assess the level of health within your animal and seek advice from  your vet if required. You will then be able to get treatment tailored to the parasites and the burden present. 

FECs do have their limitations due to a number of reasons but are an easy way to assess parasite burdens without any pain or distress to the animal, and a relatively cheap price tag. FECs can only detect eggs and may not always be a completely accurate indication of immature or adult parasite burden. This depends on the life cycle of the parasite and how long it takes them to produce/shed eggs. Similarly, the time spent in an infectious environment can also have an impact as, although an animal may have become infected with a parasite, it may not have had enough time to produce a detectable level of eggs.

We hope that this gives you a better understanding of what a FEC is and how useful they can be! We really believe they should be your go to for health monitoring. Don’t leave it until it’s too late, keep an eye on your animals regularly. If you have any questions, we are always happy to answer them. You can contact us at enquiries@ridgewayresearch.co.uk or reach us on (+)44 01594563809. If you would like a FEC, click here.

Want to know more? Here are some good resources on why you should use FECs in your husbandry practice, and how to take samples!

Farmers Weekly – 10-step guide to taking a sheep faecal egg count


Farming UK