Tapeworms

Action – Include Embelin Syrup (2:5-dihydroxy-3-lauryl-p-benzoquinone) in the feed for about 20 days in the autumn and if thought necessary late in the following spring or at any other time. Tapeworms are greyish-white segmented worms found in the intestines of horses throughout the world. Segments and eggs are past in the horses faeces onto grass in the pastures. Oribatid mites that live in the grass eat the eggs, which develop in the mites. These mites climb onto the blades of grass and are then ingested by the horse where they develop into adult tapeworms, which continue the cycle. Generally the highest level of infection is found in late summer. Use EMBELIN SYRUP for a period during the spring and summer and again in the autumn to help control tape worms. The levels of oribatid mites become less during the winter months especially during frosty conditions. A horse is unable to be infected without the mite as a primary host.

What you need to know

Tapeworms are a member of the group of parasites called flatworms, which also includes flukes.  The tapeworms are referred to as cestodes.  There are three species Anoplocephala perfoliata, Anoplocephala magna, and Paranoplocephala mamillana.  Certain types are more prevalent in certain geographical areas. Tapeworm segments (prognostics) contain both male and female organs.  Prognostics progress through development from immature, mature, adult, and gravid.  This last segment contains fertile eggs, sloughs off and passes in the dung.  An intermediate host, an oribatid or free-living mite found on pastures, eats the tapeworm eggs which undergo a period of development of two to four months inside the mite before reaching the infective or cysticercoid stage.  For a horse to become infected with a tapeworm, it must, as it grazes, ingest mites containing the immature or cysticercoid stage of the parasite.  The chances of a horse becoming infected are high because there are millions of oribatid mites in pasture.

Effective wormers: Pyrantel (Double Dose), Praziquantel,

More information

Three species of tapeworms are found in horses: Anoplocephala magna , A perfoliata , and Paranoplocephala mamillana . They are 8-25 cm long (the first usually being the longest, and the last the shortest). Anoplocephala magna and P mamillana usually are in the small intestine but may also be in the stomach; A perfoliata is found mostly in the cecum but may also be in the small intestine. The life cycle is similar to that of Moniezia spp in ruminants ( Tapeworms , Tapeworms) and involves free-living oribatid mites as intermediate hosts. Diagnosis is by demonstration of the characteristic eggs in the faeces, but because the discharge of proglottids is sporadic, a single faecal examination may not be diagnostic. In light infections, no signs of disease are present; in heavy infections, GI disturbances may occur. Unthriftiness and anaemia have been reported. Ulceration of the mucosa is quite common in the area of attachment of A perfoliata , and this has been suggested as one cause of intussusception. Intestinal perforation, peritonitis, and subsequent colic have been associated with Anoplocephala infections. Colic from disturbances of the ileocecal area was shown to be more likely in horses with tapeworm infections than in those not infected. Colic due to tapeworm infections often recurs. Often at the site of attachment of tapeworms, there is inflammation and ulceration that may become secondarily infected or abscessed.

Anoplocephala spp can be effectively treated with pyrantel salts; normal dosages (6.6 mg/kg) of pyrantel pamoate are 87% effective, while double the normal dosage is >93% effective. Daily administration of pyrantel tartrate (2.65 mg/kg) removes Anoplocephala spp . Praziquantel (0.75-1.0 mg/kg), although not approved for use in horses, is 89-100% effective in the removal of A perfoliata . Praziquantel (at 1 mg/kg) appears to be effective in removing P mamillana , pyrantel salts are not.

On facilities where tapeworms are prevalent, clinical signs of tapeworm infections can be prevented by pyrantel salts, either routinely administered on a daily basis during the grazing season or administered at purge or double purge dosages within an interval de-worming program. Treatment of horses with purge or double purge dosages of pyratel pamoate immediately before turn out and at the end of the grazing season is likely to be most beneficial.