"Ideally you want to keep young horses separated from adults, especially those with high FECs, though often that is hard to
do," states Diane Little, DVM, North Carolina StateUniversity College of Veterinary Medicine. "You always want to put young
horses, especially those that have low immunity, onto clean pastures. The ideal situation would be to cross-graze a pasture
for a couple of months with some beef cattle or goats, to clean it up, then to put that year's weaned crop/weanlings/yearlings
on that pasture, and then later in the season after they've cleaned that grass up, move your adult horses onto that pasture."
Strongyles attached to the wall of the large intestine of a horse.
It is important not to overgraze or overstock the pastures. It is recommended that the pastures are rested periodically. If
it is possible, cross-grazing with other species, is good practice to try to reduce pasture contamination. Therefore when
each host eats larval parasites of the other, the larvae are killed.
An increased level of pasture hygiene is necessary, especially with respect to composting manure before it is spread onto
the fields. Collection of feces from the pasture twice weekly is recommended. Removal of eggs and larvae by pasture cleaning
and composting the feces, removes most of the parasites. Such measures as picking up the horse droppings manually or use of
a vacuum sweeper have been used on pastures. Chain harrowing also breaks up manure piles, helping expose the larvae and eggs
to the sun and weather helping to kill them.
According to Gene Lyons, PhD, University of Kentucky Gluck Equine Center, there has been some research on spraying pastures
with chemicals to kill stages of domestic animal internal parasites, but the problem is that such chemicals may also kill
the good organisms, like soil nematodes, arthropods, etc. Experimentally, it has been shown that certain fungi can kill parasite
larvae within the manure.