Page 78 - The Veterinary Care of the Horse

Manual removal is time-consuming but the usual method for small establishments. There is

now a range of machinery available to pick up the droppings from larger areas.
VetBooks.ir paddocks have rough areas of long, sour grass where the horses pass their droppings. The
Dropping removal has the added benefit of increasing the grazing area. Untended horse

larval contamination of the rough areas is much higher than that of the rest of the field and

fortunately the horses avoid eating the sour grass. They prefer to graze the rest of the field
which will be much closer cropped. Removal of the droppings can reduce the size of the
rough areas. The muck heap should be fenced off from the grazing area as the larvae can

migrate many metres.

If good pasture hygiene is combined with regular monitoring of worm egg counts, it is
often possible to reduce the number of worming treatments given in a year.

Harrowing

Harrowing the pasture where droppings are not regularly picked up is generally not
recommended as it spreads the infective larvae into the grazing area where they can survive

for 6–9 months in cool weather. It should only be done if the field can be rested a sufficient
length of time for the larvae to die.

Stocking density and mixed grazing
The fields should not be overgrazed because the horses are then more likely to eat

contaminated grass from the rough areas. Where horses are grazed with sheep or cattle, the
ruminants eat the rough areas and clear the eggs and larvae without becoming infected.

Pasture rotation

Resting pastures is effective at reducing contamination, but strongyle larvae can survive over
winter and ascarid eggs can remain viable for years. Where possible, grazing foals on the

same pasture in subsequent years should be avoided. Routine worming of all horses before
moving onto new pasture is no longer recommended as this means that the fresh pasture will

be contaminated with the resistant strains of worms rather than the resistant strains being
diluted with susceptible strains.

Introducing a new horse
It is recommended that a new horse with unknown history is routinely treated with

moxidection and tested to find out if there is a need for tapeworm treatment. This will