The detection of worms, and estimation of their number (the worm burden) is important in diagnosing animals with disease, and also in monitoring worm control programmes.  The staple of detection is known as the Faecal Egg Count, or Worm Egg Count (FEC/WEC).  This is performed on fresh faeces, and looks for worm eggs, the theory being that the more eggs there are, the more adults there are likely to be, which has been proved to be largely true.  We receive results as a number of eggs per gram of faeces (e.p.g.), and the number present guides treatment.  Generally, <400 e.p.g. needs no treatment, >400 e.p.g. requires treatment, although the situation of the horse also has some influence in deciding treatment.  Just as an aside, if a horse produces 400 eggs per gram of faeces, and produces approximately 5kg of faeces a day, that is a massive 200,000,000 (two hundred million) eggs produced by the horse in a day.  This is what we are aiming to keep away from your pasture!  There has been some concern that the traditional FEC will not detect extremely low numbers of eggs in faeces, which can be important in some diseases.  If this is the case then your vet may recommend sending the sample to a specialist lab which can perform a more sensitive concentrational test.

The 5 round structures are strongyle eggs, as seen under the microscope.

If you would like a FEC performed on your horse, then please contact the office.  We will require a fresh sample of faeces that should either be delivered in <24 hours, or refridgerated.  Currently the cost of a FEC is less than £15.

Recently a blood test for detecting tapeworm antibody has become available to us.  This test has some limitations as it looks at antibody levels, which can persist for months to years after the tapeworms have been killed.  However, it is useful as a monitoring tool, as increasing antibody levels will indicate an active infection.