Horse Worm Infestation

Today, we have had three inquiries regarding the infestation of worms in horses, pinworm in all cases.  What can you do to limit or prevent the risk of worm infestation in your horses?

A couple of simple management processes will help you control worm burdens in your paddocks.  The first is to ensure that all new horses introduced to your property or paddocks have been suitably wormed and quarantined for a few days after the worming paste has been administered.  The second is, manage your horse manure.  This can either be done by collecting all manure from your paddocks and allow it to compost in an area outside of your paddocks.  Alternatively, establish a paddock rotation system so that paddocks are mown, rake and rested before horses are returned to it. 

Most worm eggs or worm lavae can not survive in the heat of composting or the extremes of climatic temperatures in paddocks allowed to rest for an extended time.  Raking your paddocks as part of paddock rotation can also be an effective means of improving your soil health.  A good book on managing and rotating your paddocks is 'Managing Horses on Small Properties' by Jane Myers

Rotating your wormers is also an important part of managing your horse's worm burden.  Most 'all wormers' are mectin based vermicides, generally including ivamectin or abamectin.  Wormer manufacturers have produced 'rotational wormers' that include non-mectin vermicides.  These are design to work in conjuction with all-wormers to help prevent the build up of resistant worms and help remove mectin resistant worms.  Common rotational wormers are Ammo Rotational Wormers, Panacur 100, Strategy T, Worma Paste and Worma Drench.   You can follow the manufacturer's recommendation for wormer rotation or manage your own rotation.  Our website includes a list of horse wormers with the vermicide chemicals used in each.  This will help you understand the wormer chemicals used previously and an appropriate rotational wormer

Finally, your vet may have recommendations for your horse's specific worm infestation.  This may include higher dosages of specific wormers or more frequent worming over a short period of time.  In all cases, these practices should only be made strictly in terms of your vet's recommendation.

In all cases, keep a record, or remember what wormers you have previously used on your horses.