牛病毒性腹泻

• 大多数在10天后康复
Most recover in 10 days
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Fra Baidu bibliotek
临床症状
呼吸型
• 持续间歇热
Continuous to intermittent fever
Clinical Signs
Respiratory Form
• 心率加快，但肺音正常
Increased hear rate but normal lung sounds
May be lame if they live long enough
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诊断
• 根据型 Depends on form • 临床症状 Clinical signs • 双份血清中和试验 Paired serum neutralization • 病毒分离 Virus isolation
Diagnosis
MLV（修饰的活病毒疫苗） MLV
弱毒疫苗（死苗） Attenuated vaccine (killed)
• 怀孕牛用安全，但免疫期短 Safe in pregnant animals but short duration of immunity
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• 免疫抑制病毒，使动物易感染其它疾病
Virus is immunosuppressive and predisposes animal to other diseases
• 病毒可通过胎盘
Virus crosses the placenta
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病因/发病机理
Cause & Pathogenesis
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预防
免疫程序
• 用于未怀孕牛 Use in non-pregnant cattle • 每年加强免疫Yearly booster
Prevention
• 鉴定和挑选持续感染动物 Identify persistently infected animals and cull Vaccination program
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Laboratory and Pathology
• 组织学——淋巴组织坏死——Peyer’s斑 Histology – necrosis of lymphoid tissue – Peyer’s patches
实验室和病理学诊断
• 白细胞减少 Leucopoenia
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治疗
• 补液纠正脱水
Fluids for dehydration
• 多系统病毒病 • 古典/胃肠型 • 呼吸型 • 生殖型 Multisystem viral disease Classical/Gastrointestinal Form Respiratory Form Reproductive Form
• 病毒性腹泻/粘膜病（BVD/MD型） BVD/MD Form
牛病毒性腹泻
Bovine Viral Diarrhea (BVD)
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韩 特 博 士
Prepared by: Dr. Terry Hunt BSc. DVM MRCVS Dairy Herd Health Specialist China – Canada Animal Health Initiative
BVD/MD – grave prognosis
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Sequelae
• 免疫抑制，因此增加了继发感染的易感性
Immuno-suppressive so increased susceptibility to secondary infections
后遗症
• 持续感染的带毒动物
Persistently infected carrier animals
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病因/发病机理
Cause & Pathogenesis
披膜病毒科（瘟病毒属） Toga virus (pestivirus)
• 通过带毒动物、病畜及污染物质（粪便、唾液、精液 、子宫排泄物、流产的胎儿和胎盘）直接接触传播
Transmitted by direct contact with carrier or sick animals and contaminated materials (feces, saliva, semen, uterine discharge, aborted fetus & placenta)
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生殖型——经胎盘感染
BVD/MD型
BVD/MD Form
感染了细胞病和无细胞病的生物型
• • Infection with cytopathic & non-cytopathic biotypes 100%死亡率，但发病率低 100 % mortality but low morbidity 最初经胎盘感染胎儿 Were originally infected as fetus - transplacental 许多临床动物在6—24月龄 Most clinical animals are between 6 and 24 months of age 口腔和鼻腔线形糜烂 Oral & nasal linear erosions
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危险因素
• 未免疫的动物 • 应激
Risk Factors
Non-vaccinated animals Stress
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临床症状
Clinical Signs
典型胃肠型 Classical Gastrointestinal Form • 突发性腹泻 Explosive diarrhea • 反应迟钝，精神萎靡，厌食
•
•
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BVD/MD型
• 食欲废绝和恶病质
Total anorexia and cachexia
BVD/MD Form
• 持续性脱水、腹泻
Persistent watery diarrhea
• 鼻腔和眼有粘液脓性排出物
Mucopurulent nasal & ocular discharge
• 如果存活时间足够长，可能跛行
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鉴别诊断
• • • • • • • • • •
Differential Diagnosis
腹泻和糜烂性疾病Diarrhea & erosive diseases 沙门氏菌病 Salmonella 冬季痢疾 Winter dysentery 蓝舌病 Blue tongue 口蹄疫 Foot & Mouth Disease 牛恶性卡他热 MCF 牛瘟 Rinderpest 水疱性口炎 Vesicular stomatitis 丘疹性口炎 Papular stomatitis 其它原因的流产 Other causes of abortion
Treatment
• 预防性抗生素
Prophylactic Antibiotics
• 仔细护理
Good nursing care
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预后情况
• 警惕临床病例
Guarded for clinical cases
Prognosis
• 流产牛
Aborting cows will breed back
• BVD/MD型—预后不良
• 如果无继发感染，大多数在10天后康复
Most recover in 10 days if no secondary infection
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Reproductive Form Transplacental infection • • • • • 第一个三个月 1st trimester 流产 Abortion 第二个三个月 2nd trimester 木乃伊胎儿 Mummified fetus 先天性畸形——小脑发育不全，眼缺陷，牛犊弱小 Congenital abnormalities – cerebellar hypoplasia, ocular defects, weak small calves • 持续性感染小牛犊 Persistently infected calves • 第三个三个月 3rd trimester • 正常牛犊有BVD效价Normal calf with a titre to BVD
Dull, depressed and anorexia
• 双相热 Biphasic fever • 口腔有糜烂斑—舌头、口腔粘膜
Oral lesions – tongue, mucosa of mouth
• 免疫抑制—容易发生继发感染
Immunosuppressive – predisposed to secondary infections