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Swine ascariasis
猪蛔虫病
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Group members
Introduction
Morphology
Life cycle
Epidemiology
Signs or symptoms
Lesions
Diagnosis
Control
组员：
演讲：钟秀玲
PPT制作：李秀珍、谭之博
翻译：刘橼利
资料收集：杨灵吉
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Introduction(简介)
• Swine ascariasis is a nematodiasis(线虫病)
caused by the Ascariasis suum, which lives
on the pig’s small intestine.
• The disease has a wide range of host species,
especially in the insanitary pigsty(不卫生的猪
场) and malnutrition pigs(营养不良的猪) .
• Piglets infected with the parasite would have
growth retardation , or even death.
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Morphology(病原形态)
1、Eggs:
It consists of four layers, the outermost layer of shaggy
albuminous membrane(蛋白膜), then within the true
membrane(真膜), the chitosan membrane(几丁质膜) and the
yolk membrane (脂膜).
There are something difference in shape between fertilized
eggs(受精卵) and unfertilized eggs(未受精卵). The unfertilized
eggs are longer and narrow than fertilized eggs.
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Eggs (虫卵)
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Eggs (虫卵)
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Morphology(病原形态)
2、Adults :
Fresh parasite is carnation or amber.
It has three lips.
Its surface equips with a thick cuticle .
Male’s length of body is 15 ~ 25cm, and the ventral
tail bends, which looks like fish-hook(鱼钩). Female is 20
~ 40cm long, quite straight but with the slightly blunt
tail end(虫体较直，尾端稍钝) .
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Adults(成虫)
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Life cycle(生活史)
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Life Cycle
Ascaris suum migrate up in the body of pig:
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Epidemiology(流行病学)
The prevalence(流行) of swine
ascariasis is very broad.
It generally happens in poor
management of pigsty, especially in the
3 to 5 months of age’s piglets, and
always affect the piglet’s growth and
development, even death.
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Epidemiology
The main reason of the disease with a high
morbility(高致病率) are that:
①Simple life cycle. It don’t need secondary
host
②With high fecundity of female adult(强大的
繁殖能力). It can produce 3 billion eggs all its
life.
③The high resistance to a variety of external
environment, because of eggs with fourlayers.
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Symptoms(症状)
①Larvae migrate to the liver, causing liver tissue
hemorrhage(出血), degeneration(变性) and necrosis(坏
死), forming cloudy spots of milk spot(乳斑) with about
1cm.
②Migrating to the lungs, causing pneumonia(肺炎).
and the clinical diagnosis is cough, tachypnea(呼吸急
促), fever, inappetence(食欲不振) and the spirit of
melancholy(精神沉郁).
③Large amount of ascaris often condensate integrated
group(凝集成团), formating intestinal blockage(肠阻塞),
leading to intestinal rupture(肠管破裂).
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Symptoms
Sometimes ascaris can enter into the bile
duct(胆管), causing bile duct blockage, and
jaundice(黄疸) or other symptoms.
Others: malnutrition(营养不良) 、
emaciation(消瘦)、anaemia(贫血)、fever(体温
升高)、 colic(疝痛) etc.
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Symptoms
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Lesions(病变) in lung
The initial stage of
pneumonia(肺炎), with
densification of lung tissue
and the surface has
large numbers of
ecchymosis(出血斑).
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Lesions in liver(肝脏)
Larvae migrate to the liver, causing liver
tissue hemorrhage(出血), degeneration(变性)
and necrosis(坏死), formating cloudy spots
of milk spot(乳斑), about 1cm，which is the
most characteristic lesion(最主要的特征病变)
of the disease.
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Lesions
The pigs died of ascariasis, can be found in
eggs penetrated into the bile duct, causing
the bile duct obstruction(胆管阻塞).
A small amount of adults with no visible
lesions, but catarrhal inflammation,
hemorrhage or ulcers can be found while
the large amount of parasites. When the
intestines have been ruptured(肠管破裂),
peritonitis(腹膜炎), abdominal bleeding(腹腔
内出血) can be found.
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Diagnosis(诊断)
The piglets at the age of more than 2
months, detecting eggs by Fecal
Flotation(漂浮法) or direct smear(直接涂片法).
The direct smear
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Diagnosis
Fecal Flotation(饱和食盐漂浮法)
If there are more than one thousand eggs found
in 1g feces, swine ascariasis would be diagnosed
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Control(防治)
1、Treatment(治疗)
(1) levamisole(左旋咪唑) 10mg per kilogram of body
weight, mixed feeding in the feed.
(2) Ivermectin(伊维菌素) 0.3mg per kilogram of
body weight, subcutaneous or oral.
(3) Albendazole(丙硫咪唑) 10 ~ 20mg per kg body
weight, mixed feeding in the feed.
(4) Doramectin(多拉菌素) 0.3mg per kg body weight,
subcutaneous or intramuscular injection.
(5) Flubendazole(氟苯达唑) 30mg per kg body
weight, mixed feeding in the feed.
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Control(防治)
2、Comprehensive prevention(综合性预防措施):
Periodic deworming .(预防性定期驱虫)
Improvement of breeding and management .
(加强饲养管理)
Careful sanitation of the pigsty and
playground.
(保持猪舍和运动场清洁)
Harmless disposal of feces. (猪粪的无害化处理)
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References(参考文献)
李国清.《veterinary parasitology》[M].北京：中国农业大学出版社
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