CESTODES
TAPEWORM (Anoplocephala
perfoliata, Anoplocephala magna & Anoplocephaloides mamillana)
Tapeworms are an important and potentially
very damaging parasite affecting the horse. They preferentially attach
themselves to the junction of the small and large intestine the
ileocaecal junction. Here, they can cause bowel irritation,
intussusception (where one part of the intestine telescopes into
another), rupture, or twisting of the intestine.
It is thought that tapeworm may be responsible for up to 20% of surgical
colics. Tapeworms are present, to a greater or lesser extent, in the
majority of horses.
Parts of the country with acidic soils (for example, heath land), which
favour the survival of the intermediate host of the tapeworm (the forage
or oribatid mite), tend to have the highest level of infection.
Recent studies have shown that far from
being a seasonal problem, tapeworm
infection occurs all year round. This is
because the forage mite not only
lives
on
pasture,
but also survives perfectly well in
hay and on bedding, For this reason, six-
monthly dosing (at double the standard dose for Pyrantel based products) is an essential port of any worming programme.
Appearance
Tapeworms in horses are generally
much shorter than dog or cat worms, they are flat, triangular and
relatively short being approximately 8 cm long by about 1.5 cm
wide. However the equine
tapeworm grow up to 20cm long, white in colour. Rarer species can be
up to 80cm long. They live
in huge numbers attached to the gut wall at a natural narrowing of the
gut (the ileocaecal junction).
Symptoms:
Can cause colic, sometimes fatal, by blocking blood vessels. Current
research estimates that over 20% of cases of spasmodic colic are
related to tapeworm burden
