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Important Helminth Parasites of Horses
by an aloes ball. In some cases excessive purgation may result following the
use of raw linseed oil. This undesirable action is probably due to impurities in
the oil and hence a good grade of oil should be used. It is, however, better
to use the following mixture: for weanlings, castor oil four to six ounces
and neutral oil one pint; for yearlings and two-year-olds, castor oil six to
eight ounces and neutral oil one pint; for three-year-olds and older, castor oil
eight to ten ounces and neutral oil one and a half pints. Some prefer the
following formula : For a 1,000-lb. or heavier animal mix four to five drm.
of oil of chenopodium, one and a half ounces of turpentine, five to six ounces
of castor oil and sufficient of a light mineral oil to make a pint. Pregnant
mares should not be treated with this drug.
Carbon-tetrachloride is also very effective against strongyles—especially
the blood-sucking ones. It can be safely used in treating pregnant mares.
It is given in doses of six to twelve fluid drm. (25 to 50 c.c.) to an animal
weighing 1,000-lb. It is administered through a stomach tube which must
be passed well into the stomach, otherwise, the drug is liable to cause a spasm
of the cardia, followed by regurgitation and inhalation of the fluid with fatal
results.
Normal butylidine chloride is also a very effective drug. It is given
in doses of 2.5 to 3 ounces (75-90 c.c.) to an animal weighing 1,000-lb.,
followed in five hours by raw linseed oil at the rate of one quart per 1,000-lb.
body-weight.
Since a large number of larvae may be migrating in the body, a single
treatment with any of the above drugs will not be effective. No drug is
known which will kill these young migrating worms. Treatment should,
therefore, be repeated in from four to six weeks by which time they would
have reached the intestines.
Tonic drugs such as sodium bi-carbonate
or ferrus sulphate are useful supplements to worm treatment. The former
is given in subcutaneous injections in a dose of 45 grains in 10 c.c. of distilled
water once a week. The latter is given in a dose of 2 drm. daily mixed with
grain feed. These should be given over a period of six to eight weeks. These
tonics aid in the formation of red-cells and haemoglobin which assist the
animal in overcoming anaemia.
As prophylactic measures, moist pastures and overstocking should be
avoided. If possible, rotation of pastures should be practised. Attention
should be paid to the sanitation of the stables and paddocks to prevent the
larvae from contaminating feed and water. Foals require special attention.
They should be kept away from older animals on clean pastures. Proper
disposal of manure will go a great way in reducing the infection by killing
off the eggs and larvae through the heat produced by fermentation. When
manure is stacked in large compact heaps, it ferments and the heat thus
produced kills the eggs and larvae of the parasites. The heat on the outer
surface of the heap is, however, not sufficient and hence the outer three or
four inches of the exposed manure should be turned over every week or so. The
addition of certain chemicals also aids in the destruction of the parasite