加拿大奶牛肉牛钩端螺旋体病

1、钩端螺旋体病Leptospirosis Prepared by: Dr. Terry Hunt Translated by Dr. Ren Xiaoling 病因/发病机理 Cause & Pathogenesis钩端螺旋体 180 在牛，L. hardjo & L. pomona最重要Leptospira serovars 180 L. hardjo & L. pomona - most important in cattle与公共健康有关-可以传染给人Public Health Concern infective to humans通过采食或皮肤接触携带者或感染动物的尿道、流产胎儿和子宫分

2、泌物传染Transmitted by ingestion or skin contact from carrier or infected animals via urine, aborted fetuses and uterine discharges可通过已感染雄性动物的精子传染（人工授精或自然交配）Can be transmitted in semen of infected males (AI or natural breeding)穿透粘膜或皮肤-潜伏期4-10天Penetrates mucous membranes & skin - 4-10 days incubation微生物传

3、播至肝、肾、肺，生殖道，CSF和乳房Bacteremia spreads to liver, kidneys, lungs, reproductive tract, CSF & udder微生物寄生于肾脏，CSF，眼睛和生殖道Organism persists in kidneys, CSF, eye & reproductive tract发病率10-30%，但致死率5%，除非犊牛感染非常高Morbidity of 10-30% but a case fatality rate of 5% except much higher in calves流产率达30%Abortion rate up

4、 to 30%危险因素Risk Factors死水Stagnant water 灌溉过的牧场Irrigated pasture沼泽地，？和泥地Marshy areas, feedlots and muddy fields携带者尿中含脱落的生物体Carriers shedding organism in urine临床症状Clinical Findings急性Acute L. pomona 犊牛Calves高烧，厌食，精神沉郁High fever, anorexia & depression溶血性贫血，血红蛋白尿，黄疸，粘膜有瘀点Hemolytic anemia, hemoglobinuria,

5、 jaundice & mucous membrane petechiation 肺充血，心率加快，2-3天内死亡Pulmonary congestion, high heart rate and death in 2-3 days成年牛Adults L. hardjo轻微的全身症状，但明显无Mild systemic signs but marked agalactiae乳房肿胀，乳呈黄色，有血呈橘黄色Udder is limp and milk is yellow/orange color with blood3-4周内可能流产May be abortion in 3-4 weeks慢性C

6、hronic L. hardjo有以上症状，但也流产-常在怀孕后期（7-9月）Above signs but abortion also more frequently 3rd trimester不孕，流产，死胎Infertility, abortion and stillbirth感染的犊牛早熟，虚弱Premature, weak, infected calves诊断Diagnosis很难诊断，要求实验室确诊（牛群血清学）Difficult and requires confirmatory lab (herd serology)鉴别诊断Differential Diagnosis急性Acu

7、te血红蛋白尿Bacillary hemoglobinuria分娩后血红蛋白尿Post-parturient hemoglobinuria边虫病Anaplasmosis 流产Abortion 布氏杆菌病Brucellosis病毒性腹泻BVD牛传染性鼻炎IBR诺卡氏菌流产Nocardia abortion实验室和病理学诊断Laboratory and Pathology很难培养微生物Difficult to culture organism免疫荧光试验-尿，胎儿样品Immunoflourescence- urine, fetal samples 显微凝集试验 (MAT)Microscope Ag

8、glutination test (MAT)牛群血清学-300表示感染Herd serology 300 indicate active infection尸体剖检 急性贫血，黄疸 和血红蛋白尿Post-mortemAcuteanemia, jaundice & hemoglobinuria慢性 间质性肾炎-皮质内有小、白色的病灶Chronicinterstitial nephritis small white foci in cortex治疗Treatment急性Acute链霉素12 mg/kg 用3天（一次剂量治愈L. pomona 携带者）Streptomycin 12 mg/kg bid for 3 days (single dose cures L. pomona carriers)四环素连用3天Tetracycline for 3 days非临床性Carrier群中所有动物肌肉注射链霉素25 mg/kg一次Streptomycin IM 25 mg/kg once all animals in group预后情况Prognosis犊牛死亡Calves grave流产通常只有一次Abortion usually only once预防Preventio