Moniezia spp. 莫尼茨绦虫

主讲：谭韵贤

PPT 制作：林冰媛

查找资料：王荷风，王思，刘晨

Introduction ：

They are found in the small intestine of ruminants( 反刍兽 ), like cattle,sheep,and camel （骆驼） , especially in lamb and calf.

Monieziosis is a cestodiasis caused by Moniezia sp. including Moniezia expansa ( 扩张莫尼次绦虫 ) and M.benedni( 贝氏莫尼茨绦虫 ).

M.expansa :The more common in sheep and goat than in cattle

M.benedni: The more common in cattle than in sheep and goat

Moniezia spp. have unarmed scolices( 头节 ) with four large suckers （吸盘） and very wide segments with bilateral genitalia（两组生殖器官） .

M. expansa

scolices

M. benedeni

Morphology （病原形态）

Interproglottidal glands （节间腺） at the posterior margin （后缘） of each segment extend the full width of M. expansa but occupy only the midzone of the M. benedeni segment.

Difference of M. expansa and M. benedeni

1 2

Characteristic of eggs The egg of Moniezia spp. fou

nd in cattle feces is one of the few eggs that app

ears square, and internally the pear-shaped (pyriform apparatus) characterristic of anoplocephalid （裸头绦虫） eggs can be seen.

Pyriform apparatus

( 梨形器 )

Life cycle of Moniezia spp

Definitive host: ruminants. Site of infection: small intestine Intermediate host: Forage mites ( 地螨 )

Infective stage: cysticercoid ( 似囊尾蚴 ) Prepatent preiod : month 3

Moniezia is living in small intestine of ruminant. The definitive host leaves the gravid proglottids and eggs in the feces .The oncosphere migrate into the body cavity of the mite where they develop into cysticercoids for at least 40 d and infection of the definitive host is by ingestion of infected mites during grazing.The prepatent preiod is approximately 45~60 d, but the adult worms appear to be short-lived, persist for only three months.

虫卵

地螨

Epidemiology （流行病学）

The Monieziosis distribbution is world-wide.

Moniezia spp. are the commonest in young animals, and are of low pathogenicity( 致病性 ).

Their incidence shows a seasonal fluctuation, coinciding with the active period of the vectors.

Symptoms （症状）

When there are lots of Moniezia, the intestines will become enteremphraxia( 肠阻塞 ),even have been ruptured( 破裂 ).

The toxin of parasite cause young animals being neurosis( 神经症状 ),including walking in circles( 回旋运动 ),spasm( 痉挛 ),non-food mastication( 空口咀嚼 ).

clinical symptoms ：

Decreased appetite( 食欲减退 ),emaciation( 消瘦 ),

anaemia( 贫血 ),listless( 精神不振 ),diarrhea( 腹泻 ),

gravid proglottid( 孕节 ) in feces 。

Lesions （病变）

The disease can make corpse （尸体） become thin , the colour of muscle turn light and make exudates （渗出液） in abdomen( 腹腔 ) increase.

Others: enteremphraxia( 肠阻塞 ),contortion( 扭转 ),hemorrhage( 肠粘膜出血 )

Diagnosis is based on a history of residence in an endemic area and symptoms.

Fecal examination （粪便检查） : When there is no proglottids in feces ,using the flotation method

Diagnosis （诊断）

Treatment （治疗）1. Bithionol( 硫双二氯酚 ): 50mg per kilogram of body weight for cattle, or 75mg to 100mg for sheep, P.O.

2. Niclosamide( 氯硝柳胺 ):50mg per kilogram of body weight for cattle, or 60mg to 75mg for sheep, P.O.

3. Mebendazole( 甲苯咪唑 ) ： 10mg per kilogram of body weight for cattle, or 15mg for sheep, P.O.

4. Albendazole( 丙硫咪唑 ):5mg per kilogram of body weight for cattle, or 20mg for sheep, P.O.

5. Praziquantel( 吡喹酮 ) ： 5mg to 10mg per kilogram of body weight for cattle, or 10mg to 15mg for sheep, P.O

Prevention （预防）

• 1. Deworm before adult stage(成熟前驱虫 )

• 2.Harmless disposal of feces(粪便无害化处理 )

• 3.Improvement of breeding and management ploughing and reseeding(轮牧轮种 ) to avoid pasturing in the early morning or at dust, when th

e peak of forage mite activities(避螨放牧 ) regularly testing forage mite within the pasture