牛病毒性腹瀉

1、牛病毒性腹瀉Bovine Viral Diarrhea (BVD)Prepared by: Dr. Terry Hunt Translated by Dr. Ren Xiaoling病因/發(fā)病機(jī)理 Cause & Pathogenesis披膜病毒科（瘟病毒屬） Toga virus (pestivirus)通過帶毒動(dòng)物、病畜及污染物質(zhì)（糞便、唾液、精液、子宮排泄物、流產(chǎn)的胎兒和胎盤）直接接觸傳播 Transmitted by direct contact with carrier or sick animals and contaminated materials (feces, saliva

2、, semen, uterine discharge, aborted fetus & placenta)免疫抑制病毒，使動(dòng)物易感染其它疾病Virus is immunosuppressive and predisposes animal to other diseases病毒可通過胎盤 Virus crosses the placenta多系統(tǒng)病毒病Multisystem viral disease古典/胃腸型Classical/Gastrointestinal Form呼吸型Respiratory Form生殖型Reproductive Form病毒性腹瀉/粘膜?。˙VD/MD型） BVD

3、/MD Form危險(xiǎn)因素Risk Factors未免疫的動(dòng)物Non-vaccinated animals應(yīng)激Stress 臨床癥狀Clinical Findings典型胃腸型 Classical Gastrointestinal Form突發(fā)性腹瀉Explosive diarrhea反應(yīng)遲鈍，精神萎靡，厭食Dull, depressed and anorexia雙相熱Biphasic fever口腔有糜爛斑舌頭、口腔粘膜Oral lesions tongue, mucosa of mouth免疫抑制容易發(fā)生繼發(fā)感染Immunosuppressive predisposed to seconda

4、ry infections大多數(shù)在10天后康復(fù) Most recover in 10 days呼吸型 Respiratory Form持續(xù)間歇熱Continuous to intermittent fever心率加快，但肺音正常Increased hear rate but normal lung sounds如果無繼發(fā)感染，大多數(shù)在10天后康復(fù)Most recover in 10 days if no secondary infection生殖型經(jīng)胎盤感染 Reproductive Form Transplacental infection 第一個(gè)三個(gè)月1st trimester 流產(chǎn)Abo

5、rtion第二個(gè)三個(gè)月2nd trimester木乃伊胎兒Mummified fetus先天性畸形小腦發(fā)育不全，眼缺陷，牛犢弱小Congenital abnormalities cerebellar hypoplasia, ocular defects, weak small calves持續(xù)性感染小牛犢Persistently infected calves第三個(gè)三個(gè)月3rd trimester正常牛犢有BVD效價(jià)Normal calf with a titre to BVDBVD/MD型BVD/MD Form感染了細(xì)胞病和無細(xì)胞病的生物型Infection with cytopathic

6、& non-cytopathic biotypes100%死亡率，但發(fā)病率低100 % mortality but low morbidity最初經(jīng)胎盤感染胎兒Were originally infected as fetus - transplacental許多臨床動(dòng)物在624月齡Most clinical animals are between 6 and 24 months of age口腔和鼻腔線形糜爛Oral & nasal linear erosions食欲廢絕和惡病質(zhì)Total anorexia and cachexia持續(xù)性脫水、腹瀉Persistent watery diar

7、rhea鼻腔和眼有粘液膿性排出物Mucopurulent nasal & ocular discharge如果存活時(shí)間足夠長，可能跛行May be lame if they live long enough 診斷Diagnosis根據(jù)型Depends on form臨床癥狀Clinical signs雙份血清中和試驗(yàn)Paired serum neutralization病毒分離Virus isolation 鑒別診斷Differential Diagnosis腹瀉和糜爛性疾病Diarrhea & erosive diseases沙門氏菌病Salmonella冬季痢疾Winter dysente

8、ry藍(lán)舌病Blue tongue口蹄疫Foot & Mouth Disease牛惡性卡他熱MCF牛瘟Rinderpest水皰性口炎Vesicular stomatitis丘疹性口炎Papular stomatitis其它原因的流產(chǎn)Other causes of abortion實(shí)驗(yàn)室和病理學(xué)診斷Laboratory and Pathology組織學(xué)淋巴組織壞死Peyers斑Histology necrosis of lymphoid tissue Peyers patches白細(xì)胞減少Leucopoenia 治療Treatment補(bǔ)液糾正脫水Fluids for dehydration預(yù)防性抗

9、生素Prophylactic Antibiotics仔細(xì)護(hù)理Good nursing care 預(yù)后情況Prognosis警惕臨床病例Guarded for clinical cases流產(chǎn)牛Aborting cows will breed backBVD/MD型預(yù)后不良 BVD/MD grave prognosis后遺癥Sequelae免疫抑制，因此增加了繼發(fā)感染的易感性Immuno-suppressive so increased susceptibility to secondary infections持續(xù)感染的帶毒動(dòng)物 Persistently infected carrier animals 預(yù)防Prevention & Control鑒定和挑選持續(xù)感染動(dòng)物Identify persistently infected animals and cull免疫程序Vaccination program MLV（修飾的活病毒疫苗） MLV用于未懷孕牛U