Simple Steps to Deworming:

Established habits die hard, and horse owners’ reliance on chemical parasite control is certainly well ingrained.  Working to control internal parasites includes questions such as“How often?”, “Should the drugs be rotated?”, “ Do brands matter?”.  Whichever deworming strategy you choose, another consideration horse owners must keep in mind is pasture management to minimize internal parasite ingestion by the horse. 

Deworming chemically can be accomplished using pastes (purge de-wormers), liquids, and/or daily additives given with feed.  No one deworming drug gets every equine parasite, so you should rotate different types of dewormer chemicals. Several brands contain the same chemicals, so be sure to examine the label.

Using a rotating schedule of dewormers, adult horses should be treated every 8 weeks, year round.  Products containing pyrantel pamoate , or fenbendazole should be used, with ivermectin rotated in at least 4 times a year to control stomach bots. Mares in foal should be treated 1 month prior to anticipated foaling date.  Foals through yearlings should be dewormed beginning at 1 month of age with deworming products containing pyrantel pamoate or fenbendazole products and again every 4 weeks.

Daily dewormer, such as Strongid C, does not eliminate stomach bots.  Therefore, before you begin a daily additive, use a paste treatment with ivermectin to eliminate bots and any other current infestation.  It will be necessary to use ivermectin every 6 months to remove stomach bots.  Under-dosing or skipping a day may lower the benefits of a daily dewormer.  Foals started on daily dewormer should be given ivermectin at 6 months of age.

All internal parasites have a portion of their life cycle outside the horse.  Pasture management is based on interrupting the life cycle before it gains entry to the horse.  Ample acreage (approximately 2 acres per animal) allows horses to follow their own manure-shunning practice of dividing the pasture into eating areas (lawns) and toileting spaces (roughs).  Rotational grazing (areas are given two to several weeks without grazing) allows the larval stages to emerge and then die off.  Hot weather decreases the time required whereas cool, damp weather is the preferred condition for larval development.  Rotating pasture with other livestock is helpful as none of the major equine parasite species is viable in cattle or sheep.  Mowing and harrowing pastures exposes eggs and larvae to the drying effects of open air and sunlight.  Just as daily stall cleaning is important, routine removal of manure from small turnout areas or overstocked pastures lowers the opportunity for infestation.  Compost manure removed from grazing areas or stalls, because the heat generated during composting kills parasite eggs.  Feed horses in manure-free conditions, screen new horses for parasites, and treat them if indicated before turning them out with resident horses.

Our goal at Sapulpa Equine Hospital is to educate our clients on a recommended protocol of deworming horses and provide efficient, effective, and safe products to maximize their deworming dollar.
“Basically, deworming should be simple, safe and effective,” according to Matt Klotz, DVM, formerly of Sapulpa Equine Hospital.   "Daily deworming remains a viable option, but you will need to include Ivermectin to eliminate bots."  Finally, use additional protection resting on management of pasture and confinement areas to complete a well-balanced de-worming program.