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1.
Epidemiology, pathology, and immunohistochemistry were investigated in layer hens affected with H5N1 highly pathogenic avian influenza, which occurred for the first time in 79 years in Japan. The farm, which had a total of 34,640 chickens, experienced up to 43.3% mortality before the chickens were depopulated. Clinically, the affected chickens exhibited mortality without apparent clinical signs. Histologically, hepatocytic necrosis; necrosis of ellipsoids and follicles with fibrin in the spleen; necrosis with glial nodules in the brain stem, cerebrum, and cerebellum; necrosis of acinar cells in the pancreas; and necrosis of lymphoid tissues in intestinal lamina propria were seen. Occasionally, mild bronchiolitis, degeneration of smooth muscle fibers in the cecum, and mild tubulonephrosis were noted. Immunohistochemically, influenza virus antigens were detected often in the liver and spleen, heart, intestine, gizzard, proventriculus, and oviduct. In addition, antigens were seen also in the brain, kidney, pancreas, and ovary, but seldom in the lung and trachea. Virus antigen was mainly detected in the capillary endothelium and parenchymal cells. This suggests that virus excretion from the respiratory tract was not as prevalent as that from the digestive tract in the present cases.  相似文献   

2.
Fifteen chickens, five broilers and ten layers, from the Pennsylvania 1983 outbreak of highly pathogenic avian influenza virus infection, were examined. Gross lesions in the broilers were limited to serosal petechiae and dehydration. In the layers there was comb edema, vesiculation, and necrosis. Microscopic lesions were mild to severe diffuse nonsuppurative encephalitis, very mild to severe diffuse necrotizing pancreatitis, and very mild to severe subacute necrotizing myositis involving numerous skeletal muscles and most severe in the external ocular muscles and limbs. While many of these lesions have been seen in experimental infections of chickens with influenza viruses, the pattern of organs involved in this group of chickens is distinctive.  相似文献   

3.
Livers of laying hens of Hy-Line No 934E on low erucic acid rapeseed meals and rapeseed oil were studied. Gross lesions in the livers of hens on experimental diets were moderate to severe fatty degeneration, focal necrosis and moderate to severe haemorrhage. Histological examination revealed oedematous foci and lysis of hepatocytes along with large amounts of lipid droplets in the necrotic lesions. Necrotic lesions were not always associated with large haemorrhages. Connective tissue infiltration of older degenerative and haemorrhagic lesions was not extensive. Abdominal haemorrhage from livers occurred when extensive necrosis in the form of hepatocyte lysis and some vascular changes were present, suggesting hepatocytic degeneration caused by toxic products or their metabolites present in rapeseed by-products.  相似文献   

4.
Experiments were conducted to examine the efficacy of various commercial vaccination programs for the prevention of Newcastle disease (ND) in broilers. In all, chicks were from breeders vaccinated against ND via drinking water at 75-day intervals. Vaccination was by company personnel on company premises. In Expt. 1, the initial ND vaccination programs tested were vaccination at 1 day by coarse spray with the Spra-Vac machine or by tracheal instillation with the Beak-o-Vac machine, and vaccination at 7 days via drinking water. In Expts. 2-4, birds initially vaccinated via one of the three previously mentioned methods (Spra-Vac in Expt. 2, Beak-o-Vac in Expt. 3, and drinking water in Expt. 4) were revaccinated against ND by either drinking water or coarse spray with one of two commercial portable machines (ULVA Fan or Spray Master). Serologic and challenge data in Expt. 1 indicated that although broilers vaccinated by any of the three initial routes failed to produce measurable antibody to NDV, all methods resulted in protection against NDV challenge at 35 and 49 days. However, resistance to challenge with virulent ND was greatest in birds initially vaccinated by coarse spray with the Spra-Vac machine. Results in Expts. 2-4 indicated that NDV hemagglutination-inhibition titers were highest and resistance to challenge greatest in birds initially vaccinated at day 1 by coarse spray (Spra-Vac) and then revaccinated at 14 days by coarse spray. There were no differences, however, between the portable coarse spray machines in efficacy in reimmunizing broilers against NDV.  相似文献   

5.
The immunosuppressive effect of infectious bursal disease virus (IBDV) on vaccination against Newcastle disease (ND) was compared among 2-, 3-, and 4-week-old chickens inoculated with the highly virulent IBDV field isolate 90-11 and the reference serotype 1 strain GBF-1. In all age groups, isolate 90-11 severely suppressed antibody response to ND vaccination and protective vaccinal immunity against ND. In contrast, chickens inoculated with strain GBF-1 and vaccinated with ND vaccine were well protected from the ND virus challenge. The mitogenic response to phytohemagglutinin of splenic lymphocytes from chickens inoculated with isolate 90-11 or strain GBF-1 was significantly lower than that of uninoculated controls. There was no difference between the two inoculated groups in responsiveness, although lymphocyte depletion in the thymus was more severe in chickens inoculated with isolate 90-11 than in chickens inoculated with strain GBF-1.  相似文献   

6.
对2007年3月~2008年5月泰安及周边地区鸡群新城疫抗体水平检测结果进行了统计分析,统计结果显示:抗体效价超过正常免疫水平且离散度较大,疑似新城疫野毒感染的鸡群较多.其中肉仔鸡(或麻鸡)群、育成蛋鸡群分别为12.3%、21.5%,而产蛋鸡群高达51.2%.采用接种鸡胚分离病毒和间接免疫荧光试验验证HI试验检测结果的判定,探讨鸡群的带毒状况.调查结果表明,目前鲁中地区各种鸡群的新城疫感染带毒状况较为严重,高比例带毒鸡群的存在是我国控制新城疫的最大难题.  相似文献   

7.
Chick embryos infected with Akabane virus by the yolk sac route at 6 days of incubation developed polymyositis and encephalitis. At 3 to 7 days after inoculation, skeletal muscles had myotubule degeneration, clumping of muscle cell nuclei, and infiltration of heterophils; dysplasia and aplasia were evident at 9 to 15 days after inoculation. Changes in the cerebral neostriatum and optic lobes at 2 to 11 days after inoculation included necrosis of primordial nervous tissue, hemorrhages, and hyperplasia of the vascular endothelial cells. Cavities were in nervous tissue subsequent to encephalitis. Hydranencephaly and vascular wall thickening were found 13 and 15 days after inoculation. Embryos infected intravenously at 15 days incubation had foci of encephalitis 3 to 6 days after inoculation, including neuronal degeneration, neuroglial hyperplasia, vascular endothelial proliferation, and heterophil infiltration.  相似文献   

8.
Day-old broilers were administered live and/or inactivated vaccines to assess vaccine efficacy against challenge with Newcastle disease (ND) and infectious bursal disease (IBD). Chicks were from commercial breeder pullets vaccinated against ND and IBD using several live vaccine primers followed by an inactivated ND-IBD vaccine at 18 weeks. The most efficacious initial ND-IBD vaccination program was live ND virus by eye drop and live IBD vaccine injected subcutaneously (SQ) followed 2 hours later with inactivated ND-IBD vaccine SQ. The next two most efficacious programs were live vaccine alone and the inactivated vaccine only. Inactivated vaccine given SQ had no adverse effect on live IBD vaccine given 2 hours earlier in a similar site. Administration of inactivated vaccine by vent was not as efficacious as administration SQ. A booster of a second live ND-IBD vaccine drinking water at 18 days significantly increased levels of circulating antibody, regardless of the initial vaccination program.  相似文献   

9.
Highly pathogenic H5N1 avian influenza viruses were isolated in 9 large-billed crows that died in Kyoto and Osaka prefectures in Japan from March to April in 2004. We studied 3 of the 9 crows using standard histologic methods, immunohistochemistry, and virus isolation. The most prominent lesions were gross patchy areas of reddish discoloration in the pancreas. The consistent histologic lesions included severe multifocal necrotizing pancreatitis, focal degeneration and necrosis of neuron and glial cells in the central nervous system, and focal degeneration of cardiac myocytes. All of these tissues contained immunohistochemically positive influenza viral antigens. The virus was isolated from the brain, lung, heart, liver, spleen, and kidney of the crows examined. Thus we concluded that highly pathogenic avian influenza virus was associated with clinical disease, severe pathologic changes, and death in the 3 crows.  相似文献   

10.
雏鹅实验性缺硒病及高锌对缺硒影响的病理学研究   总被引:7,自引:1,他引:6  
100只一日龄雅安本地白鹅随机分三组,分别喂给低Se(含Se0.0316ppm)、低Se高Zn(含Se0.316ppm,Zn1500ppm)和补Se(含Se0.0316ppm+0.3ppm)饲粮,饲喂8周。低Se组和低Se高Zn组于第3周至第6周发病、死亡高峰。临诊症状表现为精神沉郁、食欲降低、腹泻、脱水和生长缓慢。特征性的损害为肌胃和骨骼肌变性、坏死和钙化;胰腺萎缩、变性、坏死和纤维化;淋巴免疫  相似文献   

11.
鹅高致病性禽流感病理组织学观察   总被引:2,自引:0,他引:2  
本文对发生H5N1高致病性禽流感禽场的鹅进行了病理学观察,证实此场鹅禽流感在剖检上以眼结膜潮红出血;心肌条纹状坏死,条带样出血;胰腺有白垩状或透明坏死点;胃肠出血等为特征。组织学观察以非化脓性脑炎,胰腺坏死,心肌坏死,坏死性脾炎为主要病变,揭示了鹅禽流感的病理学变化特征。  相似文献   

12.
13.
The experiment involved 392,955 broilers from breeders vaccinated with a commercially available killed infectious bursal disease (KIBD) virus vaccine (Treatments 1 and 2) and 373,371 broilers from breeders not vaccinated with a KIBD virus vaccine (Treatment 2). The broilers from the KIBD-vaccinated breeders were divided into two treatment groups: Treatment 1 consisted of 209,457 broilers and Treatment 2 consisted of 183,498 broilers. Treatment 2 broilers were vaccinated at 10 days of age intraocularly with a commercially available modified liver infectious bursal disease virus (IBD-MLV) vaccine. Broilers in all three treatments were raised on commercially contracted farms serviced by the same company representative. Broiler performance was based on mortality, body weight, feed efficiency, condemnations, and how each farm ranked with respect to contract settlements. Compared with birds in Treatments 2 and 3 respectively, Treatment 1 broilers had 1.65% and 0.89% less mortality; 0.22 lbs. and 0.09 lbs. increased weight per bird; 0.03 and 0.03 increased feed efficiency; 0.09% and 0.32% fewer air sacculitis condemnations; and 0.57% and 0.83% fewer total condemnations. Treatment 1 broilers ranked in the top 37%; Treatment 2 ranked in the bottom 36%; and Treatment 3 ranked in the lower 57% of contract settlements for all broilers processed. The results clearly showed that Treatment 1 broilers outperformed Treatment 2 amd 3 birds and that the IBD-MLV vaccine had a detrimental effect on Treatment 2 broilers.  相似文献   

14.
To evaluate the possibility of virus transmission through feathers of call ducks, we performed two experiments, intranasal infection study and transmission study, using the Japanese H5N1 highly pathogenic avian influenza virus (HPAIV) A/chicken/Yamaguchi/7/2004 (Ck/Yama/7/04). In Experiment 1, 1-day-old, 2-wk-old, and 4-wk-old birds were inoculated intranasally with Ck/Yama/7/04. Birds in all age groups exhibited necrosis and/or viral antigens in the feather epithelium. Nonpurulent encephalitis and focal necrosis of the pancreas and heart also were common to inoculated birds. In Experiment 2, nine 2-wk-old birds that were orally inoculated with feathers of an infected call duck exhibited the nonpurulent encephalitis, necrosis of the feather epithelium, and focal necrosis of the pancreas and heart, accompanied by viral antigens. These lesions were similar to those in intranasal infection. Some birds were positive for the virus isolation from cloacal swabs and hemagglutination inhibition antibody. The infection was confirmed in seven of nine birds. This study confirmed that the Japanese HPAIV can replicate in the feather epithelium, causing necrosis in call ducks through the natural infection route. It also suggests that feathers of call ducks infected with Ck/Yama/7/04 can be a potential source of infection for unaffected birds in nature.  相似文献   

15.
A field study was designed to determine the prevalence of subclinical infectious bursal disease (IBD) in broiler chickens from a commercial poultry company. Bursae of Fabricius (BF) from two vaccinated and three nonvaccinated broiler flocks were evaluated histologically, and antibody profiles of these broiler and matched parent breeder flocks were established. Lesions of IBD, including lymphoid necrosis, stromal edema, and infiltrates of heterophils and macrophages, were first detected in BF at 24 days of age in both vaccinated and nonvaccinated chickens. At 41 days, all BF had lesions characteristic of IBD, including severe lymphoid depletion, proliferation of epithelial cells, and mild fibroplasia. Although mean maternal antibody levels (measured by enzyme-linked immunosorbent assay) in broilers were apparently protective through day 12, IBD antibodies decreased to nonprotective levels (below 1,000) by day 16 or 20. Titers began to increase by day 28 or 32 because of field exposure. Sentinel birds, placed with broiler flocks, also developed IBD antibody titers. Broiler breeders had low and nonuniform antibody titers. Prevalence of field IBD exposure was high, and existing vaccination programs were not effective.  相似文献   

16.
本试验旨在探讨高致病性猪繁殖与呼吸综合征病毒(HP-PRRSV)对地方品种猪的致病特点。将HP-PRRSV经滴鼻感染4月龄健康莱芜黑猪,观察接毒后的表现,于接毒不同时期颈静脉采血,ELISA试剂盒(IDEXX)检测外周血血清抗体水平的动态变化,定期剖杀,采集相关的器官组织制备组织切片,HE染色,观察不同组织的动态病理学变化,免疫组化染色检测病原在不同组织中的分布。结果表明,攻毒后第2天便出现一定的临床症状,但持续2d后症状就基本消失,感染猪未见死亡。攻毒后5d便可检测到抗体阳性(1/7),14d抗体达峰值。攻毒后3d便可见间质性肺炎,轻微的病毒性脑炎,实质器官颗粒变性;攻毒后7d出现典型的间质性肺炎、淋巴组织坏死、各段肠管大量嗜酸性粒细胞浸润及实质器官出现空泡变性。在攻毒后2~4周内,肺一直表现典型的间质性肺炎,病毒性脑炎逐渐加重,肾上腺变性坏死,胰腺轻微的炎性细胞浸润,甲状腺轻微充血、出血,实质器官出现严重的空泡变性。PRRSV抗原阳性信号出现在淋巴组织(淋巴结、脾、扁桃体)、气管、心、肝、肺、肾、胃、十二指肠、空肠、回肠、甲状腺、肾上腺、颌下腺、子宫、大脑及小脑内;盲肠、结肠、直肠、膀胱、胰腺、输卵管及卵巢均未见到阳性信号。阳性信号主要位于感染细胞的胞质中,偶尔出现在核内。试验结果表明:HP-PRRSV人工感染4月龄莱芜黑猪具有广泛的组织嗜性,并导致广泛的组织损伤,但临床症状表现轻微,未见死亡现象,4月龄莱芜黑猪对HP-PRRSV感染具有较强的抵抗力。试验结果为进一步研究HP-PRRSV对我国地方猪与外源品种猪的致病性差异提供了一定的理论依据。  相似文献   

17.
鹅副粘病毒病的病理变化   总被引:12,自引:1,他引:11  
对国内最近报道的一种新的传染病-鹅副粘病毒病的自然病例和人工感染病进行了系统的病理学观察。结果表明,自然病例和人工感染病例的病理变化基本一致。主要肉眼病变为肠道粘膜广泛出血,坏死、溃疡;脾脏、胰腺出现粟粒样白色坏死点;胸腺、法氏事体积缩小;脑水肿、充血。主要组织学变化为肠道粘膜上皮细胞严重坏死、脱落;肝、心、肾等器官实质细胞变性、坏死;胸腺、脾脏、法氏囊的淋巴细胞坏死,淋巴组织萎缩。  相似文献   

18.
报道了一例小熊猫急性肝炎并发急性胰腺炎的病例,介绍了病史和临床症状。根据连续2次血液生化检验,血清丙氨酸转氨酶(105 U/L,282 U/L)、谷草转氨酶(111 U/L,1 063 U/L)、ɑ-羟丁酸脱氢酶(281 U/L,542 U/L)、淀粉酶(7 330 U/L,8 410 U/L)都明显高于正常值;连续2次腹水淀粉酶检验分别为753 U/L和1 278 U/L。结果小熊猫病情急性恶化,最终治疗无效而死亡。组织病理检查:肝组织出血性坏死、肝细胞变性;胰腺淤血、腺上皮细胞变性坏死。确诊为急性肝炎并发急性胰腺炎。同时对小熊猫急性肝炎和急性胰腺炎病因、诊断及预防进行了讨论和分析。  相似文献   

19.
Strategies of Newcastle disease (ND) vaccination were demonstrated in a commercial ostrich farm in Japan. Three of 13 seven-month-old ostriches kept in a pen were vaccinated with a live ND vaccine by eye dropping for the 1st and 2nd vaccinations and spraying for the 3rd to 5th vaccinations. Antibodies against ND virus (NDV) were detected in all of the unvaccinated ostriches by virus neutralization test. At 2.5 months post final vaccination, 2 ostriches introduced into the pen raised antibodies against NDV. These data indicate that NDV may be transmitted from vaccinated to unvaccinated ostriches in the flock and that the virus may be sustained for a certain period in the flock. These data may be helpful for ND vaccination management in ostrich farms.  相似文献   

20.
BACKGROUND: Portal vein thrombosis (PVT) in cats is sparsely reported. PURPOSE OF STUDY: To evaluate the clinical signs and diseases associated with PVT in cats. Animals: 6 client-owned cats. METHODS: Medical records for cats with a portal vein thrombus diagnosed on abdominal ultrasound or at necropsy were reviewed. Signalment, historical data, underlying disorders, clinical findings, clinicopathologic and histopathologic data, diagnostic imaging findings, treatment, and outcome were recorded. RESULTS: All 6 cats identified with PVT also had hepatic disease. Evidence of a congenital portosystemic shunt was present in 3/6 cats. Two cats had primary or metastatic hepatic neoplasia. One cat had acute cholangitis, acute pancreatitis, and locally extensive acute centrilobular hepatic necrosis. Two cats were suspected to have acute thrombi and 4 cats had chronic thrombi. CONCLUSION AND CLINICAL SIGNIFICANCE: PVT might be an important concurrent finding in cats with hepatic disease.  相似文献   

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