digestive tract and may even cause intestinal blockages and ruptures. While this
sounds like a serious illness, it also helps the horse to build up immunity
against this parasite since older horses rare if ever evidence this kind of
worm. Another worm that foals easily fall prey to is the threadworm, which is
evidenced by a sudden development of diarrhea.
Bloodworms – or stongyles - are
another parasite that is quite common to horses. There are two varieties, namely
the large and the small stongyles which have somewhat different life cycles.
Once again the parasite is introduced into the horse via the ingestion of food.
Bloodworms travel via the blood vessels to the aorta that feeds the intestinal
tract where the worms will remain until they return to the intestines after
maturing enough to lay eggs. Their presence in the blood vessels may cause your
horse to develop inflammation as well as possible aneurysms and colic. Other
bloodworms may also invade the liver and spleen. The smaller kind of stongyles
is also fund in the wall of the gut itself.
A parasite that affects the mouth of the horse is the botfly. This animal
lays its eggs on the legs and shoulders of the horse. This gives you the
opportunity to remove the parasite from your horse. Failure to do so will result
in the production of larvae that will enter the horse via the mouth, as
evidenced by sores on the tongue and around the teeth, and from there they will
continue to move on to the stomach. At this point they may become responsible
for gastric ulcers and even rupture the stomach wall itself. In the spring the
larvae enter the intestinal tract where they are passed with the manure. At that
point they pupate and will become egg laying flies themselves.
Tapeworms are more common than they used to be, and will need to be include
din the worming regimen. Another worm that is common is the pinworm which is
found in the colon of the horse. If you have noticed a horse rubbing its anus
against a pole, the odds are good it suffers from the irritation caused by the
egg deposits of the worm in the perinea of the animal. Lungworms infect the
bronchi and trachea and are evidenced by a constant coughing, summer sores are
the work of the stomach worm, and the neck threadworm is transmitted by gnats
It is important to realize that while your horse may appear in danger of
infection from every angle, the worms can be fought but only if you use a
specific wormer for each infection. Once size fits all does not apply when
dealing with worms. Make sure you apply the appropriate wormer at the
appropriate time of the year to effectively interrupt the life cycle of the
worm. Begin your worming early and repeat as indicated by the veterinarian. Do
not skip a dose, even if your horse no longer displays any symptoms of worm
infection. Tapeworms must be fought at the end of grazing season while a
prolonged fly season may call for an additional treatment against botflies;
stongyles should be fought in the late fall, and rotational deworming may be the
road to traverse in order to keep your horse worm free. Speak to your
veterinarian to introduce a proper deworming rotation and then to begin a
workable rotation schedule that maximizes the effectiveness of each dewormer.