肉仔鸡非典型新城疫的诊治

2002年5月,通榆县铁西区某养殖户饲养的506只肉仔鸡,在47日龄平均体重达2．40kg时鸡群突然发病,发病率53．0％,致死率达28．3％左右。经过采取各种防治措施后,使病情迅速得以控制,现将诊治情况报告如下：     

肉仔鸡非典型新城疫的防治

鸡新城疫目前仍是养鸡业的主要疫病之一 ,近几年来牡丹江市的肉鸡非典型新城疫的发病率往往高于蛋鸡 ,但常常被误诊为慢性呼吸道病 ,使养鸡户蒙受经济损失。笔者总结临诊实践 ,就肉鸡非典型新城疫的特征、发病原因及相应的防治措施 ,总结归纳如下。1　发病特征无明显的季节性 ,发病率不高 ,临床表现以呼吸道症状为特征。剖检病变不典型 ,死亡率低 ,特别容易激发支原体和大肠杆菌病。2　发病的时间与临床症状绝大多数发生在新城疫二免和三免前后 ,鸡群首先出现的是呼吸道症状 :病鸡张口、伸颈、气喘、咳嗽 ,排黄色及绿色稀便。如不发生并发症…     

肉仔鸡非典型新城疫与肾型传支混合感染的防治

笔者在临床实践中经常见到肉仔鸡非典型新城疫与肾型传支混合感染的病例,现将诊治体会总结如下。1临床症状发病日龄多在25～40日龄之间,病鸡主要表现精神沉郁、食欲减少、饮水增加、呼噜、排白色石灰乳样稀便、扎堆、畏寒怕冷、昏睡。2剖检变化病死鸡表现皮肤和肌肉不易剥离、鸡爪干燥等脱水症状,消化道主要表现十二指肠粘膜充血、出血、溃疡,尤以十二指肠的下弯最为严重,腺胃粘膜上层往往有白色分泌物,肌胃内容物往往呈黄绿色或暗褐色,肌胃角质膜下层有时有出血斑点,小肠卵黄蒂前后肠粘膜有出血点,两盲肠尖所夹的回肠部粘膜充血或出血,盲肠…     

肉仔鸡非典型新城疫和大肠杆菌病并发的诊治

大肠杆菌病、非典型新城疫已成为危害肉仔鸡的主要疾病,2种传染病混合感染,给诊断及治疗带来很大不便。本文以山东临沂某鸡场发生一起病例,从临床症状和病理剖检观察,结合实验室诊断中的鸡胚接种、NDVHI试验、细菌学检验,最后确诊为新城疫病毒和大肠杆菌混合感染,进行了紧急免疫接种,添喂免疫增强剂,结合服用高敏感性药物—氟苯尼考及缓解呼吸道症状的氨茶碱等综合治疗措施,有效地控制住病情,并就该病的预防提出建议。     

简析非典型鸡新城疫

随着养鸡业的发展,养鸡过程中的饲养管理水平和免疫技术不断提高,使典型鸡新城疫得到了有效控制,但以低发病率和低死亡率、高淘汰率和散发为特点的非典型鸡新城疫在各地时有流行,给广大养鸡者带来了不少麻烦和经济损失。因此,非典型鸡新城疫仍是威胁养鸡业发展的重要疫病之一。     

鸡新城疫-禽流感二联灭活油苗免疫肉仔鸡抗体跟踪调查

亚洲禽流感风暴，给养禽业带来了巨大威胁和挑战。面对突如其来的禽流感疫情，强制性免疫势在必行。原本不免疫禽流感疫苗的商品代肉鸡场，不得不把禽流感疫苗列入其免疫程序。基于肉仔鸡生长周期短的特点，目前大多数鸡场采用ND-AI二联疫苗联合免疫的方法，以减少鸡群应激和节省免疫费用。为了追踪疫苗的免疫效果和免疫抗体水平消     

常见肉仔鸡腿病的防治

在饲养肉仔鸡生产中，肉仔鸡腿病是一种常见病。由于病因复杂，症状及剖检变化相似，难以诊断。据2003年5～7月份来就诊75例肉仔鸡中非典型鸡新城疫神经症状腿病(麻腿)41例占来就诊总数的55％，其余大肠杆菌、葡萄球菌感染、滑液囊炎、病毒性关节炎等腿病34例，占总数45％。     

鸽场大面积爆发新城疫的诊断

1997年9月，江苏省建湖县某鸽场饲养的3000只乳鸽，约1300余只发病，死亡998只，死亡率达33.3％，给该场造成重大经济损失。乳鸽发病期间，曾被当地兽医诊治为鸽副伤寒病，在使用庆大霉素、氯霉素等广谱抗菌素治疗无效后，来我站诊断。通过临床观察、询问、解剖、试验，确诊为鸽新城疫。鸽新城疫在我县尚属首次发生，现将该场发病情况报道如下。1 临床症状鸽发病早期食欲减退，精神不振，缩颈呆立，羽毛蓬松，体温升高。随后，腹泻下痢，排黄白、黄绿水样或糊粘状稀粪，有的全身发抖，出现转圈、歪颈、头向后仰，呈观星状。最后衰竭而死。2 …     

非典型性新城疫发病新特征及防制对策

据我院实习门诊病例显示，进入夏季以来，非典型性新城疫发病明显增多。通过走访客户、采取病料，并对正在发病和已经发过病的鸡群进行抗体检测，总结发现非典型性新城疫新的发病特征：该病多发生于20～40日龄、60～80日龄和200～300日龄鸡群：表现特点是发病率低，死亡率低，产蛋鸡群产蛋率明显下降；     

3株新城疫病毒毒力的测定

新城疫是由新城疫病毒引起鸡的一种高度接触性传染病。为了探讨本地有关区域 NDV毒力分布情况 ,将自 1 997年以来 ,从珠江三角洲不同地区分离获得的 3株 NDV的鸡胚平均致死时间 ( MDT)、1日龄雏鸡脑内致病指数 ( ICPI)和 6周龄鸡静脉内致病指数 ( IVPI)进行测定。1　材料与方法1 .1　病毒　ND野毒株 ,共 3株 ,包括 N株 (分离自南边 )、S株 (分离自狮山 )、L株 (分离自罗定 )均由本实验室分离、鉴定保存。1 .2　实验动物　 1 0日龄鸡胚、1日龄易感雏鸡 ,6周龄非 ND免疫雏鸡均由佛山燎原鸡场提供。1 .3　毒株的鸡胚传代　将 3株 ND…     

正确认识鸡新城疫的免疫机制

鸡新城疫（ND）是危害养鸡业的重要疫病之一，采取科学的免疫方法是取得良好控制效果的关键。     

Some properties of lentogenic Australian newcastle disease virus

The Newcastle disease virus (NDV) occurring in Australia is apathogenic for chickens following natural infections. Some properties of the avirulent Australian V4 strain of NDV and of 12 new isolates of NDV were compared.The viruses grew to high titres following infection of chick embryos by the allantoic cavity and allantoic fluid had infectivity titres of from $\text{10}{}^{\mathrm{8·7}}\text{to}\text{10}{}^{\mathrm{9·5}}\text{EID}{}_{50}\text{0.2}\text{ml}$. With only two isolates did sufficient mortalities occur to allow calculation of mean death times and these were in excess of 140 h. Five of nine isolates failed to kill 100% of embryos when doses in excess of 10^7·9 EID₅₀ were used. When strain V4 was inoculated into the yolk sac of 10-day-old embryos, the LD₅₀ was similar to the ID₅₀ obtained with allantoic cavity inoculation, and the mean death time was 103 h.The intracerebral pathogenicity index for strain V4 was 0.91 and 1.02 in two experiments. The index was not significantly reduced when the virus was taken through a further cycle of plaque purification or when the inoculum was heated at 56°C for 30 min. Chickens with maternally derived antibody to NDV were not susceptible to intracerebral inoculation with strain V4. Chickens dying after intracerebral inoculation with strain V4 had haemorrhagic and necrotic liver lesions. The intracerbral pathogenicity indices for four other isolates varied from 0 to 0.22.The infectivity of V4 and three other isolates was relatively stable at 56°C and that of another eight isolates was labile. Haemagglutinins of all viruses studied were stable at 56°C for longer than 60 min. None of four isolates tested lost haemagglutinin activity on treatment with ether.Haemagglutination-elution patterns were variable but four isolates did not elute from chicken erythrocytes after 24 h at 4°C and strain V4 and isolate PM12 did not elute after 96 h at 4°C. Six viruses, including V4, agglutinated erythrocytes from all of six test horses. The haemagglutinin activity of the remaining viruses varied between horses.Four viruses including V4 haemolysed chicken erythrocytes. Gradient centrifugation allowed the separation of an infectious and a noniffectious haemagglutinin. Haemolytic activity was associated with the infectious haemagglutinin.