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Faecal Egg Count - Fact Sheet


What is a faecal egg count?


A faecal egg count is a sample of your animal's dung which is viewed under a microscope to see whether there are any worm eggs present. 


How safe are DIY faecal egg counts?


DIY faecal egg counts are ONLY recommended if the person carrying them out has been suitably trained. Incorrect procedure, technique or interpretation of results could have catastrophic consequences for an animals welfare.  The protocols at ScientifEQ have been set up by the School of Veterinary Science at the University of Liverpool.  Always ask your faecal egg count provider where they received their training.


What do the results mean?


The results show the number of eggs seen in the sample, reported as number of eggs per gram.  They are interpreted to give an indication as to the level of worms in the horse rather than a specific number.  


Do they identify all worms?


Faecal egg counts identify eggs from the worms that lay eggs, in the stomach, as part of their lifecycle i.e. strongyles and ascarids. They cannot be used to identify worms with different lifecycles including pinworm, bots and tapeworm. Furthermore, the worm lifecycle includes many larval stages that are not detected through faecal egg counts. If eggs are identified then the horse will also have larvae migrating through it's system at different stages, the number of larvae at each stage cannot be measured.


Why do I need to do this test?


The worms that cause disease in our horses and ponies are developing resistance to all of the chemical wormers available.  In a nutshell they may not be working any more.  A faecal egg count is the only way to assess whether the chemicals are working.

Only 20% of horses have worms, however, over 80% are still being wormed.  Using faecal egg counts instead of wormers means that your horse or pony will only have the chemicals that they actually need.


How safe is it to reduce worming?


It is very safe if a full risk assessment is taken on the pasture contamination levels and the faecal egg counts are carried out at the correct time.  It is recommended that the interpretation of faecal egg count results should only be carried out by someone who is trained in parasitology.  Standard interpretations and recommendations are dangerous and should not be followed without checking with your vet or an independent expert such as ScientifEQ +.


Why can’t I do it myself?


If your horse or pony has a clear faecal egg count result then the standard recommendation from most commercial labs is ‘no worming needed’.  However, this is not always correct.  It is possible to have a ‘false negative’.  This is when the dung sample is taken whilst there are still active chemicals in the horse's system.  It is also always dangerous to stop worming foals and young horses as they can develop severe clinical symptoms much quicker than adult horses.  The labs who just perform the sample analysis provide standard worming recommendations and are not specific to your individual circumstances.


What does a clear result mean?


It means that there are no active adult worm eggs in the sample of dung that you have sent for analysis.  It does not mean that your horse does not have worms!!!!  The worm life cycle includes many larval stages that are not detected from faecal egg counting and there are also worms that do not lay eggs and are therefore not detectable in the sampling process. 


What is the point of faecal egg counting?


Faecal egg counting is a fantastic development in the professional parasitological tool kit.  They can be used to assess whether the chemical intervals of a worming program are effective at killing adult worms.  They can be used to detect resistance to chemical wormers and they will also detect large volumes of worms that are laying eggs.  Veterinary recommendations are to stop blanket chemical worming as it is not working any more.  It is only by replacing the chemicals with faecal egg counting that our horses will remain safe.  The incorporation of this practice into your horse health care programme should commence immediately.


Do all companies and vets offer the same service?


Every test involves the analysis of dung under a microscope, however the quality of the results will vary greatly.  There is no quality control over faecal egg counting and no qualifications needed to carry out the test.  The cost of the microscope can vary from £25 to £3,000 such as those in the veterinary universities.  This has a huge impact on the accuracy of the result.  There is also another piece of equipment that will improve the visibility of the sample.  A centrifuge spins the dung and organic matter in the sample away from the eggs.  With a centrifuge only the eggs are left to view, without a centrifuge all grass, dung matter etc. are still under the slide when viewed through the microscope.  I am certain that you can picture the difference between the quality of the two methods.



What do I do about the other worms?


ScientifEQ offer other tests to detect tapeworm, lungworm and fluke.  Tapeworm cannot be detected in a standard faecal egg count, however segments may be seen in the dung if present. Tapeworm flotation tests are available as well as the new EquiSal test which tests for antibodies in the saliva. This is a novel DIY test that works in a similar way to the ELISA blood test offered by your vet.


Worming treatment for bots is recommended if yellow eggs are seen on the horse's legs and coat in late autumn.


Pinworm can be identified by your vet taking a sellotape sample from your horse.


Other worms and diseases will be identified and diagnosed by your vet in reponse to the symptoms that your horse is showing.


For further information about faecal egg counts and worming programmes contact us.



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