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1.
两个鸡场暴发了传染性法氏囊病。B场无并发感染,死亡率为3.9％,死亡高峰出现在第6天;A场由于致病性大肠肝菌混合感染,死亡率上升到36.2％,死亡高峰提前到第3天,剖检病变更加复杂化,该场的O_2血清型大肠埃希氏菌是加剧传染性法氏囊病鸡大量死亡的真正原因。 相似文献
2.
鸡传染性法氏囊病及其并发感染 总被引：1，自引：0，他引：1
两个鸡场暴发了传染性法氏囊病、B场无并发感染，死亡率为3．9％，死亡高峰出现在第6天：A场由于致病性大肠杆菌混合感染，死亡率上升到36．2％，死亡高峰提高前到第3天、剖检部更加复杂化，该场的O2血清型大肠埃氏菌是加剧传染性法氏囊病鸡大量死亡的真正原因。 相似文献
3.
免疫鸡群暴发传染性法氏囊病的诊断 总被引：1，自引：1，他引：0
在免疫鸡群中暴发传染性法氏囊病，死亡率高达３０．７５％，病死鸡法氏囊呈胶冻样水肿外观，浆膜表面的纤维蛋白渗出物厚度达２－５ｍｍ，以法氏囊组织毒人工感染２８日龄雏鸡，能引起临床症状和死亡，复制出在自然病例中观察到的全部病理变化，其侵袭力可以突双破法氏囊弱毒疫苗的临床保护，初步证明是一株贵州省的地方野毒。 相似文献
4.
在免疫鸡群中暴发传染性法氏囊病，死亡率高达３０．７５％，病死鸡法氏囊呈胶冻样水肿外观，浆膜表面的纤维蛋白渗出物厚度达２～５ｍｍ．以法氏囊组织毒人工感染２８日龄雏鸡，能引起临床症状和死亡，复制出在自然病例中观察到的全部病理变化，其侵袭力可以突破法氏囊弱毒疫苗的临床保护，初步证明是一株贵州省的地方野毒． 相似文献
5.
鸡新城疫（ND）是由副粘病毒引起的鸡的一种高度接触性传染病，常呈败血症经过，其特征是呼吸困难，下痢和表现神经症状。近年来，由于鸡群普遍进行了新城疫（ND）的免疫接种，使得ND的发病向非典型化转变，呈散发性发生。尤其是非典型新城疫（ND），常在经过免疫接种的鸡群中出现，以呼吸道和下痢症状、发病率高、死亡率低为特征。鸡群感染ND病毒，抗病力低，极易并发传染性支气管炎病毒感染，造成大批死亡， 相似文献
6.
邢兰君 《兽药与饲料添加剂》2003,8(2):44
鸡新城（ND）是由新城疫病毒（NDV）引起的一种高度接触性传染病，常呈败血经过，其特征是呼吸困难、下痢和表现神经症状。近年来，由于鸡群普遍进行了新城疫的免疫接种，鸡新城疫发生了新的变化，鸡群发病后，临诊症状表现不明显，病理变化不典型，常以呼吸道、下痢、发病率高和死亡率低等症状出现。鸡群感染ND病毒后，抗病力降低，再加上舍内环境不良，极易并发葡萄球菌病，造成大批死亡，给养鸡业造成较大的经济损失。１临床症状病鸡精神沉郁，缩头、羽毛松乱、不食、排绿色稀便，有的表现为咳嗽，呼吸困难，有喘息音，嗉囊内充满气体… 相似文献
7.
新城疫（ND）是危害养鸡业的最主要疾病之一。各种品种、性别、年龄的鸡都易感，发病率和死亡率极高，常在90％以上。近年来，由于饲养管理水平的提高和ND免疫接种的普遍开展，ND暴发流行已很少见，但免疫鸡群发生非典型ND造成鸡只死亡或生产性能下降的病例仍屡见不鲜。由于非典型ND缺乏特征性的临诊症状和病理变化，容易发生误诊，导致NDV得不到及时消除，ND难以扑灭，给养鸡生产带来更大的经济损失。 相似文献
8.
鸡传染性腔上囊病（IBD）由传染性腔上囊病毒引起。鸡群突然发病,高发日龄在20～60日龄,特别是30日龄多见。发病率很高,死亡率一般为20%--30％。当有继发感染或合并感染时,死亡率可超过40％,该病有明显的死亡高峰,多数鸡群在发病后6～7天疫情趋于平稳。鸡场一旦暴发该病,以后每批雏鸡均可感染发病。病鸡精神萎靡不振、瘫卧、震颤,排米汤样稀便,大多鸡群在发病后3—4天达到死亡高峰。 相似文献
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10.
新城疫(ND)是一种急性高度接触性传染病。该病流行的特点是:在未免疫鸡群中,感染ND后有很高的发病率和死亡率。在获得免疫弱的鸡群中,发生ND后,病鸡呈非典型经过,即不表现明显的临床症状和病理变化,其发病率和死亡率都较低。 相似文献
11.
选取新城疫病毒(Newcastle disease virus,NDV)GX-08株对26日龄雏鸡和20日龄雏番鸭进行人工感染试验,对体外细胞培养物进行致病性试验,并进行病理组织学观察。结果表明,以105.5EID50的攻毒剂量对26日龄雏鸡和20日龄雏番鸭通过肌注接种,雏鸡的发病率和死亡率分别为100%和100%,雏番鸭的发病率和死亡率分别为70%和70%;通过点眼、滴鼻及口服接种,雏鸡的发病率和死亡率分别为80%和30%,雏番鸭的发病率和死亡率分别为20%和20%。感染鸡消化器官和部分呼吸器官病变严重,表现出典型的嗜内脏型NDV感染的病理变化特点;感染鸭则肝脏、脾脏和胰腺等实质器官病变明显,消化器官和部分呼吸器官病变较轻微。以200 TCID50的剂量对单层鸡胚成纤维细胞(CEF)和鸭胚成纤维细胞(DEF)接种,结果CEF和DEF均于24 h左右开始出现病变,并分别于96和84 h左右细胞单层完全被破坏。与CEF相比,DEF接种病毒后,细胞坏死、裂解过程迅速,合胞体形成现象显著,合胞体的数量及合胞体平均含有的胞核数较多,病毒接种后培养物上清的HA效价峰值也较高,表明GX-08株均可致CEF和DEF病变,且对DEF有更强的细胞融合能力。 相似文献
12.
非典型鸡新城疫的病因研究初报（一） 总被引：7，自引：1，他引：6
应用血清学、生物学方法、从我省产蛋量下降、HI抗体在1：128以上的疑似非典型鸡新城疫（CND）病鸡群中分离到1株病毒，经鉴定和致病力测定，明确是1株ND强毒，毒力与F48E9相近，然后采用该株野毒感染不同抗体水平的3批蛋鸡及肉鸡，结果3批蛋鸡均是低抗体滴度组（1：10－1：40）发生了CND症状，感染后6－7天开始产蛋停止，经15－17天后才恢复产蛋，高抗体滴定组（1：80以上）无明显变化，无抗体对照组出现典型鸡新城疫变化，全部死亡；病毒感染后第6、10天监测HI抗体，结果低滴度组第6天达1：80－1：160，第10天达1：160－1：1280。试验结果表明，我们分离到的NDV，既可引起典型的ND，也可引起非典型的ND；高HI抗体蛋鸡产生非典型鸡新城疫的病因之一，是由于存在低抗体鸡群而发生了CND，其高HI抗体有竞争是由于强毒感染后产生的抗体。 相似文献
13.
Alfaro JC Petrone VM Fehervari T Nava G Kogut M Nisbet D Tellez G 《Avian diseases》2002,46(3):525-534
A group of 1-day-old commercial leghorn chickens was prophylactically treated with lymphokines obtained from lymphocyte cultures of chickens previously infected with Salmonella enteritidis (S. enteritidis-immune lymphokines [SE-ILK]) with the objective to investigate the effect of SE-ILK on development of Newcastle disease (ND) infection caused by Chimalguacan strain, a Mexican velogenic ND virus (vNDV). Clinical signs, histologic lesions, and hemagglutination-inhibition (HI) serum titers were compared with four other groups, namely, chickens without SE-ILK treatment with virus challenge; with SE-ILK without virus challenge; with nonimmune lymphokine (NILK) treatment and virus challenge; with lymphokine treatment and no virus challenge. SE-ILK was administered intraperitoneally in a dose of 0.5 ml/chicken and was followed 30 min later with the challenge of vNDV in a dose of 10(7.6) 50% embryo lethal dose/ml per bird. Birds were observed during 21 days of postchallenge. Detection of histologic changes and virus isolation procedures were carried out on the third, seventh, 14th, and 21st postinoculation days. HI tests were performed first before treatment and later on the days of histologic sample collection except on the third postinoculation day. Results showed that SE-ILK administration conferred resistance to the chickens because: 1) it significantly diminished the severity of ND infection by inhibiting appearance of clinical signs (P < 0.001), lesions (P < 0.005), and histopathologic changes (P < 0.005); 2) it decreased vNDV isolation rate from the organs (P < 0.001), and 3) it potentialized and even accelerated (P < 0.005) primary immune response by antibodies in the presence of vNDV. 相似文献
14.
Otim Onapa M Christensen H Mukiibi GM Bisgaard M 《Tropical animal health and production》2006,38(4):285-289
The role of ducks in the transmission of Newcastle disease virus (NDV) to free-range village chicken was investigated experimentally.
Newcastle disease (ND) seronegative ducklings reared in a pen were infected oronasally with velogenic NDV of intracerebral
pathogenicity index (ICPI) 1.8 isolated from outbreaks in village chickens in Uganda. A first group of 3-week-old ND seronegative
chicks was mixed with the ducks and they were kept together for 7 days. Both ducks and chicks were observed for ND clinical
signs and any mortality, and they were bled and their sera were tested for ND antibodies by haemagglutination inhibition (HI)
test. The chicks were removed, euthanized and examined for any ND lesions, while the ducks were transferred to a fresh pen
and a second group of chicks was introduced and observed and treated as above. The ducks and the chicks tested positive for
ND antibodies 7 days post infection and contact, respectively, but showed no clinical signs, post-mortem lesions or mortality.
The mean ND antibody titre of the second group of chicks was lower than for the first group. This study has shown that although
ducks can be infected with velogenic NDV, they do not show clinical signs but are able to transmit NDV to in-contact chicks.
Further investigations are needed of the lack of clinical signs in the in-contact chicks and how long the ducks remain infective. 相似文献
15.
O Onunkwo J O Okoye 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1991,44(4):411-414
Infectious bursal disease was reported in a flock of 7-week old vaccinated chickens. Clinical findings and post-mortem changes were classical as well as the microscopic pathology of the bursa. Bursal homogenates from dead birds were positive for IBD virus antigen in agar gel diffusion test (AGDT). Convalescent sera obtained from birds 14 days following the onset of clinical signs were also positive for IBD virus antibody in AGDT. Seven-week old susceptible birds, each infected i/m with 0.1 ml of a bursal preparation from the outbreak, showed clinical signs of IBD on the 3rd day and were all dead by the 6th day. Their bursae were also positive for IBD virus antigen in AGDT. This is the first recorded outbreak of IBD in Southern Nigeria following inoculation with a locally produced vaccine. 相似文献
16.
2011年8月,从河南省疑似传染性法氏囊病鸡群采集病料,通过鸡胚接种、琼脂扩散试验和RT-PCR等方法,证实分离的病毒为传染性法氏囊病病毒（Infectiousbursaldiseasevirus,IBDV）,命名为HB／11株。序列分析表明,HB／11株VP2基因的核苷酸序列与GenBank中发表的部分国内外IBDV超强毒株VP2基因序列相似性在99％左右;HB／11株VP2高变区基因含有七肽基序为SWSASGS,在222、253、256、279、284、294和299位上的氨基酸残基分别是A、Q、I、D、A、I和S,具有IBDV强毒的分子特征。动物回归试验表明,30日龄鸡群接种该毒株后引起鸡群发病率为100％,死亡率为70％,剖检可见鸡传染性法氏囊病典型病变。因此该病毒为IBDV强毒株。 相似文献
17.
从哈尔滨市某肉鸡养殖场疑似传染性支气管炎的病死鸡中分离到1株肾型IBV,并对其进行鸡胚矮小化、血凝性、电镜下特征、新城疫干扰试验、致病性等生物学鉴定和N基因的RT-PCR鉴定。结果表明,该病毒分离株在鸡胚上传至第四代(F)4开始出现死亡或侏儒胚;病毒不凝集鸡红细胞;透射电镜下可见多呈球形、直径约80～120nm的病毒粒子,具有冠状病毒的典型形态特点;该病毒可干扰新城疫LaSota株在鸡胚中的增殖;将分离毒第4代尿囊液接种于6日龄雏鸡,7d后开始出现死亡,死亡率高达67%(6/9),病死鸡剖解后可见肾脏明显肿大、苍白,具有传染性支气管炎的典型病变;分离毒第5代尿囊液经N基因特异性RT-PCR获得大小约438bp的目的片断。初步确定所分离病毒为肾型IBV。 相似文献
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19.
Six congenic lines of chickens that differ from the parental inbred line RPRL-15I5 for genes in the major histocompatibility (B) complex were used to study the influence of the B haplotypes on the response of chickens to infection with virulent infectious bursal disease virus (IBDV) at 1 day or 4 weeks of age, and on the antibody response to vaccination with live or inactivated oil-emulsion (OE) IBDV vaccines at 7 weeks of age. IBDV-induced immunodepression and lesions in the bursa, spleen, and thymus in chickens infected with virus at 1 day of age were of the same degree of severity, regardless of line of chickens used. The response of blood cells to the mitogens phytohemagglutinin-M and concanavalin A was elevated in chickens infected with IBDV at 1 day of age. In an experiment conducted to study the effect of the B haplotype on IBDV infection in 4-week-old chickens, B congenic line C-12 (B12B12) showed the highest susceptibility to clinical IBD, with mortality of 79%. No detectable difference in the serological response to vaccination with live or OE IBDV vaccines was noted among chickens of various congenic lines. We conclude that the B haplotypes may influence IBDV-induced mortality, but not immunodepression or severity of lesions in lymphoid organs, or the antibody response to live or OE IBDV vaccines. 相似文献
20.
Tsukamoto K Imada T Tanimura N Okamatsu M Mase M Mizuhara T Swayne D Yamaguchi S 《Avian diseases》2007,51(1):129-132
Typically highly pathogenic avian influenza (HPAI) viruses spread very rapidly among chickens within sheds. However, the spread was slower than expected for the initial 10 days of the index farm in Japan during 2004. This slow spread, as well as the lack of gross lesions, clinical signs, or high mortality, hindered the field veterinarian from reporting a suspected HPAI outbreak to the veterinary office. To understand the field conditions for the slow virus spread, we examined contact and airborne transmission of the H5N1 virus to chickens in a negative-pressure isolator using various numbers of infected chickens and separate compartments. We found that the contact transmission did occur inefficiently when one or two chickens were infected, whereas the transmission was efficient when four chickens were infected. Airborne transmission of the HPAI virus was also dependent on the number of infected chickens and was less efficient than contact transmission. These data together with field observations suggested that number of infected chickens, chicken house types, and amount of environmental contamination might affect the virus transmission efficiency to chickens. 相似文献