Anoplocephala

classification Kingdom : Animalia Phylum : platyhelminthes Class : Eucestoda Order : Anoplocephlidea Family : Anoplocephalidae Genus : Anoplocephala Specie : A. perfoliata A .magena

Order : Anoplocephlidea Essentially tapeworms of herhivores . and devoid rostellum and hooks in their scolex and the gravid segments are wider than they are long. The intermediate stage is a cysticercoid. 'Two species of this genus are parasitic in the intestine of the horse .

Genus: Anoplocephala It is a large cestoda with market segmentation parasitising intestine of equine . There is single set of reproductive organs with numerous testes throught medulla in each proglottid . The ovary is lobed and transversely elongated Genital pores are unilateral . The eggs are present in the transverse elongated uterus. Eggs has three covering outering vetilline mambrane , middle albominous coat and an inner chitinous membrane . It is possessing a pyriform apparatus

Egg of Anoplocephala spp

Host: Horses and donkeys. Intermediate hosts: Various forage mites in the soil and pasture of the Family Oribatidae. Site : The adults are found in the small and large intestine, and the cysticcrcoids in forage mites. Species: Anoplucephala perfoliata Anoplocephala magna Distribution: World wide, A. perfoliata is the more common.

Anoplocephala perfoliata Commonly it is knowen as (lappetted cestoda) of equines ,is a special structure called lappet behind each sucker . Occurs in large and small intestine It may be grow up to 5 cm (rarely up to 8 cm) in length and 1.2 cm in breadth . The scolex is 2-3 mm in diameter The proglottids arewider than long The gravid uterus is transversely elongated sac lick and lobed . The eggs measure 65-80 µm in diameter

Anoplocephala magna It is occurs in the small intestine and rarely in the stomach of horse and other equine. It measure up to 80 cm in length and 2.5 cm in breadth . The scolex is larger than A . perfoliata , measuring 4-6 mm in width . The external seminal vesicle is well developed. The testes vary from150-200 The ovary located in the poral half of proglottide Eggs measure 50-60 µm in diameter

Life cycle indirect life cycle The adult worms lay eggs already in the intestine of their final hosts that are shed with the feces, or the gravid segments containing the eggs are shed out and release the eggs only outside the host. The eggs are sticky and adhere to the vegetation or soil particles. Depending on the species and the region they can survive for months in the environment and some may survive cold winters, but they are very sensitive to dessication  The oribatid mites ingest the eggs, which hatch in their gut and develop to cysticercoids in the body cavity of the mites within 2 to 4 months. They are infective for the final hosts. Cysticercoids can survive for months inside the mites, which on their turn have a live span of up to 18 months.

The final host becomes infected after ingesting contaminated mites while grazing. The mites are digested and release the cysticercoids that attach to the gut's wall and develop to adult tapeworms within about 6 weeks. The prepatent period (time between infection and first eggs shed) is about 6 to 10 weeks, suggesting that more than one generation can follow during a normal season in regions with a warm and humid climate.

Clinical sings Anoplocephala infections are usually benign for adult horses and usually do not cause clinical signs. Horses of all ages may affected, but clinical cases have been reported mainly in animals up to 3-4 years.  Foals are more susceptible to suffer from infection. Attachment points to the mucosa are cause, irritated, abscessed or ulcerated and become easily infected with bacteria. Massive infections can cause colic, diarrhea, and weight losses. Intestinal perforation, peritonitis and anemia have also been reported.  Anoplocephala magna can cause enteritis (hemorrhagic or ulcerative), Anoplocephala perfoliata is known to cause fatal intestinal blockage when large number of tapeworms cluster in the ileocaecal area

PATHOGENESIS Due to attachment by scolex of A.perfoliata near the ileocaecal orifice cause ulcerative lesions are produced . Partial occlusion of ileocaecal orifice due to granulation tissue may be one of causes intussusception . In infection with A . Magna there may be catarral or haemorrhagic enterities in small intestine

Immune response The equine intestinal cestode A . perfoliata has been the subject of recent epidemiological and immunological studies because of its suspected association with intestinal disease in the horse. shown that the IgG subtype antibody response to component of the parasite excretory/secretory (E/S) antigen is positively correlated with parasite intensity . The relative importance of exposure to infection and the development of acquired immunity as determinants of the observed age-intensity pattern is considered.

Diagnosis Demonstration of typical egg in feacal smear under microscope getting on confirmatory diagnosis. Depend on clinical sings like digestive upsets , unthriftness, colic etc . But difficult to differentiate from other common causes.

Treatment Praziquantal Niclosaminde Mebendazole and bithionol have been found effective .

control Is usually difficult as grass mite are wide spread Infected animals may be treated before entering in to grazing area .

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