加拿大奶牛肉牛副结核病

1、副结核病Johnes Disease (Paratuberculosis)Prepared by: Dr. Terry Hunt Translated by Dr. Fu Xiaoping病因/发病机理 Cause & Pathogenesis分支杆菌属副结核耐酸性细菌Mycobacterium paratuberculosis Acid-fast bacteria慢性、不可治愈等导致长期腹泻、消瘦Chronic, incurable, granulomatous leading to chronic diarrhea and emaciation在世界各地的野生牛、山羊、绵羊中均可见到See

2、n world wide and will occur in wild ruminants, sheep and goats低发病率，高死亡率（因长期消耗性腹泻）Low morbidity but high mortality from chronic wasting diarrhea口粪途径传播Oral fecal transmission潜伏期长，但在临床症状出现前感染动物大多会接触感染Long incubation period but infected animals become contagious before clinical signs精液中可发现细菌、但不通过性传播Bact

3、eria found in semen but venereal transmission not found胎儿通常在子宫内被感染Fetus can commonly be infected in utero感染牛的牛奶中存在细菌Infected cows excrete organism in milk危险因素Risk Factors病菌在牧场可存活一年以上Organism can survive on pastures for over a year病菌携带者通常因应激或分娩刺激而表现为临床Carrier animals are common but with stress or par

4、turition can become clinical无可靠的测试方法来发现病菌携带者No reliable test to detect carrier animals临床症状Clinical Findings2岁前无症状No signs in cattle before two years of age although they may be shedding.2-6岁为高发期Peak cases in 2-6 year olds开始表现为奶产量下降May start with a decrease in milk yield不发热或毒血症No fever or toxemia食欲良好

5、Good appetite体况差Loss of body condition似豌豆汤样腹泻Diarrhea is like thick pea soup粪便无臭、无血、无脱落物和粘膜No smell, no blood, no castes and no mucusDiarrhea is continuous although may lessen with dry feed数周或数月的渐渐性消瘦、虚弱Progressive emaciation and weakness over a period of weeks or months结果是安乐死End result is euthanasi

6、a山羊和绵羊Sheep & goats消瘦，通常不见腹泻Emaciation but usually not the diarrhea seen in cattle诊断Diagnosis依据临床症状、既往史、血清学检查Based on clinical signs, herd history and serology鉴别诊断Differential Diagnosis沙门氏菌Salmonellosis 球虫病Coccidiosis慢性病毒性腹泻Chronic BVD寄生虫感染Parasitic infestation慢性铜缺乏症Chronic copper deficiency 实验室和病理学

7、诊断Laboratory and Pathology目的是测定出亚临床的细菌携带者Goal is to detect the sub-clinical carrier state粪便Feces标准粪便培养-敏感性好但培养困难，费时8周时间Standard fecal culture sensitive but difficult and takes 8 weeks血清学 Serology补体结合试验假阳性-特异性低Complement fixation test-false poor specificity琼脂扩散试验？ - 敏感性不好AGID not good sensitivity酶联免疫

8、吸附试验-敏感性差ELISA poor sensitivity尸体解剖-盲肠淋巴结-染色，镜检细菌Post mortem-ileo-cecal lymph node stain and look for bacteria结节性肠炎Granulomatous enteritis治疗Treatment无治疗价值No treatment is of value 可能减轻症状，和使用异烟肼(一种抗结核药)May reduce signs and shedding with Isoniazid预后情况Prognosis不良淘汰携带者Poor cull carriers预防Prevention & Control发展无副结核病的牧场Develop Johnes free herd每六个月进行粪便培养一次-淘汰阳性牛Fecal culture all adults at 6 month intervals cull positive淘汰阳性牛的全部后代Cull all off spring from positive cows使用无副结核病的公牛精液Use only semen from