Feacal Egg Counts..

Feacal egg counts are a great way of assessing your horse’s health with regard to internal parasites.  The four most common internal parasites are:

  •  Encysted redworm, Roundworms, Tapeworms and Bots.

However only Roundworms reliably excrete eggs in proportion to their infestation.

Encysted redworm are a casing point…. their life cycle involves a ‘hibernation’ phase where the larvae burrow into and live in the actual gut wall for a variable period of time and then are triggered into hatching out through the gut wall again and becoming egg laying adult worms.

You can, and I have recently had, a scenario where the feacal egg count is ZERO yet the next day the horse has diarrhoea with characteristic small redworm larvae wiggling around in the poo!

Tapeworms have a prolonged life cycle and excrete egg laden sacs at intermittent periods.  These can be seen with the naked eye lying on the surface of feaces appearing as large “rice” segments.

Bots lay eggs on the lower limbs of horses which are ingested and the larvae then end up attached to the lining of the stomach. These bot larvae are occasionally seen in the feaces looking like a bumble bee without wings.

Another misnomer with the Negative feacal egg count could be PINWORM infestation, where the adult worm lays eggs on the perineum, around the anus.  Again a zero count is possible with adult pinworm seen lying on the feaces!