课件：牛病毒性腹泻.pptVIP

1,牛病毒性腹泻 Bovine Viral Diarrhea (BVD),2,韩 特 博 士,Prepared by: Dr. Terry Hunt BSc. DVM MRCVS Dairy Herd Health Specialist China Canada Animal Health Initiative,3,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) 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,4,病因/发病机理 Cause & Pathogenesis,多系统病毒病 Multisystem viral disease 古典/胃肠型 Classical/Gastrointestinal Form 呼吸型 Respiratory Form 生殖型 Reproductive Form 病毒性腹泻/粘膜病（BVD/MD型） BVD/MD Form,5,危险因素 Risk Factors,未免疫的动物 Non-vaccinated animals 应激 Stress,6,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 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 大多数在10天后康复 Most recover in 10 days,7,临床症状 Clinical Signs,呼吸型 Respiratory Form 持续间歇热 Continuous to intermittent fever 心率加快，但肺音正常 Increased hear rate but normal lung sounds 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,8,生殖型经胎盘感染 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,9,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624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,2019/8/7,10,可编辑,11,BVD/MD型 BVD/MD Form,食欲废绝和恶病质 Total anorexia and cachexia 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 May be lame if they live long enough,12,诊断 Diagnosis,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,13,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,14,实验室和病理学诊断 Laboratory and Pathology,组织学淋巴组织坏死Peyers斑 Histology necrosis of lymphoid tissue Peyers patches 白细胞减少 Leucopoenia,15,治疗 Treatment,补液纠正脱水 Fluids for dehydration 预防性抗生素 Prophylactic Antibiotics 仔细护理 Good nursing care,16,预后情况 Prognosis,警惕临床病例 Guarded for clinical cases 流产牛 Aborting cows will breed back BVD/MD型预后不良 BVD/MD grave prognosis,17,后遗症 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 持续感染的带毒动物 Persistently infected carrier animals,18,预防 Prevention,鉴定和挑选持续感染动物 Identify persistently infected animals and cull 免疫程序 Vaccination program MLV（修饰的活病毒疫苗） MLV 用于未怀孕牛 Use i