Understanding equine tapeworm as a cause of colic?
(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.
Appearance
Tapeworms in horses are generally much shorter than dog or cat tapeworms, they are flat, triangular and relatively short being approximately 8 cm long by about 1.5 cm wide. Segments can detach it is it is these segments that may on rare occasion be spotted by horse owners. 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).
Treatment
Recent
studies have shown that far from being a seasonal problem, tapeworm infection
occurs all year round. The lifecycle of the tapeworm starts when the adult worm
sheds fertilised eggs within the horses’ droppings. These are eaten by an
intermediate host called the forage mite. This mite is then eaten by the horse,
along with hay or grass, and over the next few months, adult tapeworms develop
within the gut.
The
forage mite not only lives on pasture, but also survives perfectly well in hay
and on bedding so there is no real seasonality to tapeworm infestation however
most infestations are picked up after prolonged periods at grass. Therefore
early autumn and spring are prime times for tapeworm infections to be managed.
Tapeworm infestation cannot be diagnosed by faecal examination,
so incorporating wormers that are effective against tapeworm in
your overall worming and animal health planning schedule alongside other tools such as saliva tests and
good pasture management are essential.
If treatment is required then Pyrantel
based products should be used at twice the standard dose. Combination wormers containing Praziquantel are effective in treating tape worm or if only the tape
worm burden itself is to be tackled then products containing only Praziquantel
are available.
Symptoms
Can
cause colic, sometimes fatal, by blocking blood vessels.
SH Wetherald E-SQP
