牛病毒性腹泻 (1).ppt

牛病毒性腹泻 (1).ppt

《牛病毒性腹泻 (1).ppt》由会员分享，可在线阅读，更多相关《牛病毒性腹泻 (1).ppt（17页珍藏版）》请在冰豆网上搜索。

1,牛病毒性腹泻BovineViralDiarrhea（BVD）,2,韩特博士,Preparedby:

Dr.TerryHuntBSc.DVMMRCVSDairyHerdHealthSpecialistChinaCanadaAnimalHealthInitiative,3,病因/发病机理Cause&Pathogenesis,披膜病毒科（瘟病毒属）Togavirus（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Transmittedbydirectcontactwithcarrierorsickanimalsandcontaminatedmaterials（feces,saliva,semen,uterinedischarge,abortedfetus&placenta）免疫抑制病毒，使动物易感染其它疾病Virusisimmunosuppressiveandpredisposesanimaltootherdiseases病毒可通过胎盘Viruscrossestheplacenta,4,病因/发病机理Cause&Pathogenesis,多系统病毒病Multisystemviraldisease古典/胃肠型Classical/GastrointestinalForm呼吸型RespiratoryForm生殖型ReproductiveForm病毒性腹泻/粘膜病（BVD/MD型）BVD/MDForm,5,危险因素RiskFactors,未免疫的动物Non-vaccinatedanimals应激Stress,6,临床症状ClinicalSigns,典型胃肠型ClassicalGastrointestinalForm突发性腹泻Explosivediarrhea反应迟钝，精神萎靡，厌食Dull,depressedandanorexia双相热Biphasicfever口腔有糜烂斑舌头、口腔粘膜Orallesionstongue,mucosaofmouth免疫抑制容易发生继发感染Immunosuppressivepredisposedtosecondaryinfections大多数在10天后康复Mostrecoverin10days,7,临床症状ClinicalSigns,呼吸型RespiratoryForm持续间歇热Continuoustointermittentfever心率加快，但肺音正常Increasedhearratebutnormallungsounds如果无继发感染，大多数在10天后康复Mostrecoverin10daysifnosecondaryinfection,8,生殖型经胎盘感染ReproductiveFormTransplacentalinfection,第一个三个月1sttrimester流产Abortion第二个三个月2ndtrimester木乃伊胎儿Mummifiedfetus先天性畸形小脑发育不全，眼缺陷，牛犊弱小Congenitalabnormalitiescerebellarhypoplasia,oculardefects,weaksmallcalves持续性感染小牛犊Persistentlyinfectedcalves第三个三个月3rdtrimester正常牛犊有BVD效价NormalcalfwithatitretoBVD,9,BVD/MD型BVD/MDForm,感染了细胞病和无细胞病的生物型Infectionwithcytopathic&non-cytopathicbiotypes100%死亡率，但发病率低100%mortalitybutlowmorbidity最初经胎盘感染胎儿Wereoriginallyinfectedasfetus-transplacental许多临床动物在624月龄Mostclinicalanimalsarebetween6and24monthsofage口腔和鼻腔线形糜烂Oral&nasallinearerosions,10,BVD/MD型BVD/MDForm,食欲废绝和恶病质Totalanorexiaandcachexia持续性脱水、腹泻Persistentwaterydiarrhea鼻腔和眼有粘液脓性排出物Mucopurulentnasal&oculardischarge如果存活时间足够长，可能跛行Maybelameiftheylivelongenough,11,诊断Diagnosis,根据型Dependsonform临床症状Clinicalsigns双份血清中和试验Pairedserumneutralization病毒分离Virusisolation,12,鉴别诊断DifferentialDiagnosis,腹泻和糜烂性疾病Diarrhea&erosivediseases沙门氏菌病Salmonella冬季痢疾Winterdysentery蓝舌病Bluetongue口蹄疫Foot&MouthDisease牛恶性卡他热MCF牛瘟Rinderpest水疱性口炎Vesicularstomatitis丘疹性口炎Papularstomatitis其它原因的流产Othercausesofabortion,13,实验室和病理学诊断LaboratoryandPathology,组织学淋巴组织坏死Peyers斑HistologynecrosisoflymphoidtissuePeyerspatches白细胞减少Leucopoenia,14,治疗Treatment,补液纠正脱水Fluidsfordehydration预防性抗生素ProphylacticAntibiotics仔细护理Goodnursingcare,15,预后情况Prognosis,警惕临床病例Guardedforclinicalcases流产牛AbortingcowswillbreedbackBVD/MD型预后不良BVD/MDgraveprognosis,16,后遗症Sequelae,免疫抑制，因此增加了继发感染的易感性Immuno-suppressivesoincreasedsusceptibilitytosecondaryinfections持续感染的带毒动物Persistentlyinfectedcarrieranimals,17,预防Prevention,鉴定和挑选持续感染动物Identifypersistentlyinfectedanimalsandcull免疫程序VaccinationprogramMLV（修饰的活病毒疫苗）MLV用于未怀孕牛Useinnon-pregnantcattle每年加强免疫Yearlybooster弱毒疫苗（死苗）Attenuatedvaccine（killed）怀孕牛用安全，但免疫期短Safeinpregnantanimalsbutshortdurationofimmunity,