鸡坏死性肠炎综合防治

<正>1病原鸡坏死性肠炎是由产气荚膜梭菌（A型或C型）引起的一种急性非接触性传染病。产气荚膜梭菌是自然界中广泛存在的细菌，在土壤、饲料、粪便及人和动物的肠道中都可以检测到。正常鸡的嗉囊、小肠和盲肠中也存在该菌，但并不会引起发病。当鸡受到外界不良刺激或因疾病等原因导致免疫力下降时，肠道菌群遭到破坏，肠道中的产气荚膜梭菌可大量繁殖，导致坏死性肠炎发生。     

奶牛场魏氏梭菌病的预防

奶牛魏氏梭菌病是一种急性传染病．又称为猝死症。临床上以病牛突然死亡．消化道和实质器官出血为特征。该病病原体魏氏梭菌为土壤常在菌，常随污染的饲料、饮水等进入奶牛肠道，在奶牛机体抵抗力降低，外界不良诱因．影响下．魏氏梭菌在肠道内大量繁殖，产生毒素。引起发病。其预防措施如下。     

健康与子宫内膜炎奶牛阴道菌群结构的比较研究

利用16SrDNA结合PCR-DGGE技术分析比较了产后45d健康奶牛和患子宫内膜炎奶牛阴道内细菌群落多样性及其差异,并通过切胶、克隆测序等步骤分析了奶牛阴道细菌种类。研究结果表明,患病奶牛DGGE图谱的条带数量、多样性指数均显著高于健康奶牛;健康奶牛阴道优势菌主要有清酒乳杆菌(Lactobacillus sakei subsp.)、魏斯杆菌(Weissella koreensis sp.)和地衣芽孢杆菌(Bacillus licheniformis),而患病组奶牛阴道内此3种优势菌含量显著降低或缺失,且也无其他明显优势菌存在;从健康和患病奶牛阴道内均分离出脆弱拟杆菌(Bacteroides fragilis)、溃疡拟杆菌(Bacteroides helcogenes)、无乳支原体(Mycoplasma agalactiae)、普氏菌(Prevotella dentalis)、产气荚膜梭菌(Clostridium perfringens str.)和肠球菌(Enterococcus hirae)等常见病原微生物,在患病奶牛阴道内分离出大肠杆菌(Escherichia coli str.K-12 substr.)、梭杆菌(Fusobacterium nucleatum subsp.)等特定致病菌。研究结果提示,子宫内膜炎奶牛阴道内菌群结构比健康奶牛更为复杂,且无优势菌,阴道菌群结构失衡可能是奶牛发生子宫内膜炎的原因。     

一起梅花鹿肠毒血症的诊治

正肠毒血症是由魏氏梭菌引起的鹿的一种急性传染病。本病主要是饲养不当,胃肠正常消化机能被破坏,魏氏梭菌大量繁殖产生毒素,导致全身毒血症;特点是发病急,死亡率高,危害严重。魏氏梭菌广泛存在于自然界中,常存在于土壤、污水、动物粪便、饲料中。健康路的肠道中亦有本菌的存在。当饲料突然改变,尤其是食入大量富含蛋白质或冰冻的青绿多汁饲料后,肠道正常的消化和免疫机能受到干扰和破坏,菌群失调,而该菌大量繁殖产生毒素,经吸收后引起发病。往往青壮     

产气荚膜梭菌肠毒素的致病机理研究进展

产气荚膜梭菌是一种重要的人兽共患病的病原体，可引起人的食物中毒和抗生素相关腹泻，产气荚膜梭菌肠毒素是该菌的一个非常重要的致病毒素，在引起人的胃肠疾病方面起着关键性的作用，本文对产气荚膜梭菌肠毒素产生、细胞毒性和组织学作用以及在胃肠粘膜上造成损伤的致病分子机理等方面的研究内容进行论述。     

成年奶牛产气荚膜梭菌肠毒血症的防治

奶牛产气荚膜梭菌肠毒血症是由产气荚膜梭菌(魏氏梭菌)在肠道中大量繁殖产生毒素而引起奶牛的毒血症,多见于犊牛,成年奶牛发生此病少见。2006年黑龙江省农垦857农场发生成年奶牛产气荚膜梭菌(D型)肠毒血症,东北农业大学专家专门为     

成年奶牛产气荚膜梭菌肠毒血症的防治

奶牛产气荚膜梭菌肠毒血症是由产气荚膜梭菌在肠道中大量繁殖产生毒素而引起的奶牛毒血症,多见于犊牛,成年奶牛少见。2006年857农场发生成年奶牛产气荚膜梭菌（D型）肠毒血症,后经治疗,病情得到控制,现将治疗和预防措施介绍如下。     

鸭源魏氏梭菌病的诊断与治疗

正为建立鸭源魏氏梭菌病的诊断与治疗方法,对临床32周龄樱桃谷种鸭肠道臌气病例展开研究。结果为剖检可见肠道臌气、肠黏膜覆有黄色纤维素性假膜,实验室分离到革兰氏阳性粗短杆菌,经PCR扩增及测序分析,鉴定为魏氏梭菌。同时在场区饲料中也检测到该菌,因此种鸭感染可能跟饲料污染有关。临床通过优化饲料配方、入场前饲料细菌检测,并对临床病鸭使用恩拉霉素后,死淘现象得以有效控制。     

艰难梭菌感染的发病机理、影响及防治策略

艰难梭菌是一种革兰氏阳性、厌氧芽孢杆菌,广泛分布于人类和动物的肠道和环境中。近年来,艰难梭菌感染的频率和严重程度不断增加,该菌不仅感染动物,目前已经成为与医疗机构相关性腹泻的重要病原体,是住院患者出现发病和死亡的重要原因。所以艰难梭菌感染已经是一种必须引起重视的人畜共患病,会对公共卫生安全构成严重威胁。这种病原体通过粪-口途径传播,临床表现多种多样,从无症状携带到不同程度的腹泻,再到导致死亡的的结肠炎。本文介绍了有关艰难梭菌感染的基本知识,希望有助于艰难梭菌感染的防控参考。     

兔真菌性肺炎的流行、鉴别诊断与防治

1流行特点 兔真菌性肺炎是由烟曲霉菌引起的深部真菌病,以呼吸道,尤其是肺和支气管炎为主要特征的疾病。烟曲霉菌和他所产生的孢子,在自然界中分布很广。在稻草、谷物、发霉的饲料、笼子、用具和空气中都有本菌的存在。对畜禽的血液、神经和组织能产生毒害作用的毒素。仔兔对烟曲霉菌最容易感染,经常成窝发生。如果产箱及窝内有烟曲霉菌孢子存在并严重污染,当仔兔出生不久即可能被感染,但一般为慢性经过。     

Comparison of the odds of isolation, genotypes, and in vivo production of major toxins by Clostridium perfringens obtained from the gastrointestinal tract of dairy cows with hemorrhagic bowel syndrome or left-displaced abomasum

OBJECTIVE: To compare the frequency of isolation, genotypes, and in vivo production of major lethal toxins of Clostridium perfringens in adult dairy cows affected with hemorrhagic bowel syndrome (HBS) versus left-displaced abomasum (LDA). DESIGN: Case-control study. ANIMALS: 10 adult dairy cattle with HBS (cases) and 10 adult dairy cattle with LDA matched with cases by herd of origin (controls). PROCEDURE: Samples of gastrointestinal contents were obtained from multiple sites during surgery or necropsy examination. Each sample underwent testing for anaerobic bacteria by use of 3 culture methods. The genotype of isolates of C. perfringens was determined via multiplex polymerase chain reaction assay. Major lethal toxins were detected by use of an ELISA. Data were analyzed with multivariable logistic regression and chi2 analysis. RESULTS: C. perfringens type A and type A with the beta2 gene (A + beta2) were the only genotypes isolated. Isolation of C. perfringens type A and type A + beta2 was 6.56 and 3.3 times as likely, respectively, to occur in samples from cattle with HBS than in cattle with LDA. Alpha toxin was detected in 7 of 36 samples from cases and in 0 of 32 samples from controls. Beta2 toxin was detected in 9 of 36 samples from cases and 0 of 36 samples from controls. CONCLUSIONS AND CLINICAL RELEVANCE: C. perfringens type A and type A + beta2 can be isolated from the gastrointestinal tract with significantly greater odds in cattle with HBS than in herdmates with LDA. Alpha and beta2 toxins were detected in samples from cows with HBS but not from cows with LDA.     

Pathogenesis of Aspergillus fumigatus infection in pigeons in the Sudan.

The pathogenesis of a pigeon isolate of Aspergillus fumigatus in a local breed of pigeons in the Sudan was tested. The spores inoculated intravenously resulted in an acute disease with 100% of mortality within six days. At necropsy, pinpoint and miliary lesions were prominent in the liver, spleen, lungs and kidneys. Histopathological examination detected lesions in the liver, heart, lungs, kidneys, spleen and brain. Hyphae and/or spores were encountered in all these organs. The presence of A. fumigatus was confirmed by reisolation from the liver, lungs and kidneys.     

Induction of Noninflammatory Pain in an Experimental Foot Lameness Model in Horses

The mechanism by which nonsteroidal anti-inflammatory drugs mitigate pain caused by a heart bar shoe (HBS) model of lameness is unknown. The purpose of this study was to determine if this HBS model of lameness induces inflammation in horses. Five healthy adult horses from a university teaching herd were enrolled. A custom HBS was applied to the left front foot of each horse, followed by induction of the American Association of Equine Practitioners Lameness Score of 4. Inflammatory markers including serum amyloid A (SAA) concentration, local venous tumor necrosis factor alpha and prostaglandin E2 (PGE2) concentrations, and foot temperature were measured before lameness induction and 1, 3, and 13 hours after lameness induction. Lameness induction using the HBS model did not significantly increase production of plasma SAA, tumor necrosis factor alpha, or PGE2 concentrations at measured time points. Immediately and 1 hour after lameness induction, dorsal coronary band temperatures were higher in the left front foot compared with the right front foot, but there was no difference at 3 or 13 hours. In conclusion, the HBS model did not induce inflammation as assessed by select inflammatory markers, suggesting that the HBS model induces mechanical rather than inflammatory pain. This should be considered when using the HBS model to assess analgesic drugs in horses.     

Whole blood and tissue fungal DNA quantification in the diagnosis of canine sino-nasal aspergillosis

Various combinations of tests are used to confirm the diagnosis of canine sino-nasal aspergillosis (SNA) because false-positive and false-negative results can occur with each test. Therefore, the aim of this study was to evaluate whether detection of fungal DNA in blood and nasal tissue samples was of value in the clinical diagnosis of this disease. Four groups were included in the study (dogs with SNA, lymphoplasmacytic rhinitis or nasal neoplasia, and control animals). Real-time PCR assays detecting DNA from all Penicillium and Aspergillus species (PenAsp assay) or species-specific DNA from A. fumigatus, A. terreus, A. flavus and A. niger were applied to whole blood and nasal tissue samples. Results obtained by PCR were compared between the groups. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) for fungal DNA detection were compared with those for alternative diagnostic procedures including histopathology, serology and fungal culture. Significantly more fungal DNA was detected by the PenAsp assay in tissue biopsies from dogs with SNA than in the three other groups. Sensitivity, specificity, PPV and NPV for this method were 1.00, 0.06, 0.32 and 1.00. A. fumigatus DNA was detected in seven tissue biopsies from dogs with SNA and in one biopsy from a dog with a nasal tumour. Sensitivity, specificity, PPV and NPV for this diagnostic test were 0.50, 0.97, 0.87 and 0.82. No significant difference was found between the groups with respect to the amount of DNA detected in blood by the PenAsp assay. Sensitivity, specificity, PPV and NPV for this method were 0.71, 0.24, 0.31 and 0.64. A. fumigatus DNA was detected in the blood of three dogs with SNA and sixteen dogs without SNA. Sensitivity, specificity, PPV and NPV for this diagnostic tool were 0.21, 0.45, 0.15 and 0.54. Detection of A. fumigatus DNA in nasal tissue had the highest specificity, PPV and NPV but sensitivity of this method was low. Detection of fungal DNA in whole blood was of no value in the diagnosis of SNA.     

The association of Clostridium botulinum type C with equine grass sickness: a toxicoinfection?

The cause of grass sickness, an equine dysautonomia, is unknown. The disease usually results in death. Gastrointestinal (GI) dysfunction is a common clinical manifestation in all forms of the disease. It is generally thought that equine grass sickness (EGS) is caused by an ingested or enterically produced neurotoxin which is absorbed through the GI tract. Clostridium botulinum was first implicated as a causative agent when it was isolated from the GI tract of a horse with EGS in 1919. The aim of the present study was to investigate the hypothesis that EGS results from toxicoinfection with C. botulinum type C: growth of the bacterium in the GI tract with production of toxin (BoNT/C). Ileum contents and faeces from horses with EGS were investigated for BoNT/C, and indirectly for the presence of C. botulinum type C, and compared with control samples from horses without EGS. BoNT/C was detected directly by ELISA in the ileum of 45% (13/29) of horses with EGS compared to 4% (1/28) of controls, and in the faeces of 44% (20/45) of horses with EGS compared to 4% (3/77) of controls. Levels of up to 10 Mlg toxin/g wet weight of gut contents were observed. The one control horse with detectable toxin in the ileum had been clinically diagnosed as having acute EGS, but this was not confirmed by histopathology. The organism was detected indirectly by assaying for BoNT/C by ELISA after enrichment in culture medium. C. botulinum type C was shown to be present in 48% (14/29) of ileum samples and 44% (20/45) of faecal samples from horses with EGS, compared with 7% (2/27) of ileum samples and 8% (6/72) of faecal samples from controls. These results support the hypothesis that EGS results from a C. botulinum type C toxicoinfection.     

Hepatobiliary Scintigraphy in the Evaluation of Feline Liver Disease

Hepatobiliary scintigraphy (HBS) was performed in 10 cats with histologically documented hepatobiliary disease. The scintigraphic patterns were classified into one of 5 categories: normal, primary hepatocellular dysfunction, primary in-trahepatic cholestasis, mixed hepatocellular and intrahe-patic cholestasis, and extrahepatic obstructive patterns. Initial attempts were made to correlate specific disease entities with HBS patterns, but a consistent relationship could not be determined. A correlation between the histological severity of a given hepatic disease and the HBS pattern was made. All cats (n = 5) with a mixed hepatocellular and intra-hepatic cholestasis scintigraphic pattern with normal gallbladder function had a histologically severe form of their individual hepatic disease. Three of the 4 cats with an intra-hepatic cholestasis pattern and normal hepatocellular and gallbladder function had histologically mild or moderate forms of their individual hepatic disease. One cat had an extrahepatic obstructive pattern where no radiopharmaceu-tical was identified in the gallbladder or small intestine by 3 hours postinjection. This study suggests that HBS can be useful in cats with hepatobiliary disease to assess the severity of hepatic dysfunction, and to determine if extrahepatic biliary obstruction is present. Correlation between HBS patterns and specific disease entities such as hepatic lipidosis or cholangitis-cholangiohepatitis syndrome could not be made in this study.     

Use of hepatobiliary scintigraphy in the diagnosis of extrahepatic biliary obstruction in dogs and cats: 25 cases (1982-1989).

Twenty-five animals (21 dogs and 4 cats) in which hepatobiliary scintigraphy (HBS) was performed between 1982 and 1989 were included in a retrospective study to determine the utility of HBS for diagnosis of extrahepatic biliary obstruction. Final diagnoses, which were based on liver biopsy results and surgical findings in all animals, were hepatocellular disease alone (n = 17), hepatocellular disease and extrahepatic biliary obstruction (n = 7), and normal liver (n = 1). Hepatobiliary scintigraphy was performed by use of 99mTc-diisopropyl iminodiacetic acid in all cases. All 7 cases of extrahepatic biliary obstruction were confirmed at surgery. In animals with biliary obstruction, HBS failed to demonstrate radiolabel within either the gallbladder or intestine at any time. Using nonvisualization of the intestine by 180 minutes as the scintigraphic criterion for diagnosis of biliary obstruction, sensitivity was 83% and specificity was 94% in this series. Hepatobiliary scintigraphy was concluded to be an accurate indicator of extrahepatic biliary obstruction in this group of animals. High serum bilirubin concentration at the time HBS was performed did not appear to reduce the diagnostic usefulness of the scintigraphic findings.     

Factors affecting the prevalence of foot pad dermatitis, hock burn and breast burn in broiler chicken

1. Standardised data on flock husbandry were recorded on 149 broiler farms during the 4 d prior to slaughter. 2. Birds were examined at the slaughterhouse for contact dermatitis lesions. Foot pad dermatitis score (FPDS) and hock burn score (HBS) were measured on five point scales. Carcase rejection data were also collected. 3. The mean percentage of birds in each flock with: moderate or severe foot lesions was 11.1% (range 0-71.5%); moderate or severe hock burn was 1.3% (range 0-33.3%); and, breast burn was 0.02%. 4. A general linear model was developed to examine factors associated with mean flock FPDS. Assuming a linear relationship, within the range of data collected and with all other factors remaining the same, every 1% increase in the proportion of Genotype A birds in the flock was associated with an increase in mean FPDS of 0.003, every one-point increase in litter score was associated with a 0.326 increase in mean FPDS and every one-point increase in flock mean HBS was associated with a 0.411 increase in mean FPDS. Flock mean FPDS was associated with feed supplier and was higher in winter. 5. The general linear model developed for flock mean HBS, found that every one-point increase in mean FPDS increased mean HBS by 0.090, every one-point increase in litter score increased HBS by 0.119 and, every 1% increase in small/emaciated birds decreased mean HBS by 0.333. Reduced HBS was also associated with increased final litter depth, younger slaughter age and an increased percentage of dietary wheat. For every 1% increase in Genotype A birds, a decrease in flock mean HBS of 0.003 would be expected. 6. An effect of hatchery was also identified.     

Effect of long-term intermittent periodontal care on canine periodontal disease

The periodontal health status was assessed in two groups of dogs which had received different levels of periodontal care over a two-year period. The dental group received regular dental scaling and polishing, and intermittent daily tooth brushing, while the control group received no periodontal care. All dogs developed gingivitis, and two (one from each group) showed evidence of incipient periodontitis. The dental group had a reduced gingivitis index (GI) compared with the control group only when they had received daily tooth brushing before the GI assessment. When the dogs had not had their teeth brushed for four weeks before the assessment, the GI was not significantly different to that in the control dogs. This suggests that continual periodontal care throughout life is of great importance and questions the benefits of intermittent oral care. The GI of the palatal and lingual surfaces in all dogs was significantly higher than the GI of the buccal surfaces. Thus, all tooth surfaces may need to be cleaned to achieve optimal periodontal health.     

Risk factors associated with hemorrhagic bowel syndrome in dairy cattle

OBJECTIVE: To determine risk factors associated with hemorrhagic bowel syndrome (HBS) among dairy cattle in the United States and identify characteristics of HBS in individual cows. DESIGN: Cross-sectional, population-based survey. SAMPLE POPULATION: A stratified random sample of 1,013 dairy operations with > or = 30 cows located in 21 states. PROCEDURE: Information on management and animal health-related topics was collected with a questionnaire. RESULTS: HBS was estimated to have been observed on 9.1% of operations during the preceding 5 years and on 5.1% of operations during the preceding 12 months. Factors found in multivariable analysis to be associated with the occurrence of HBS during the preceding 12 months were large herd size, administration of bovine somatotropin, and routine use of milk urea nitrogen concentration to determine ration composition. Use of pasture as part of the lactating cow ration during the growing season was associated with decreased odds of HBS in operations with rolling herd average milk production < or = 20,000 lb, whereas in operations with higher milk production, use of pasture was not associated with occurrence of HBS. For individual cows with signs consistent with HBS, the third lactation was the median of the parity distribution and the median time between parturition and the onset of clinical signs was 104 days. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that management practices implemented to achieve high milk production may increase the risk of developing HBS in dairy cattle. Increased consumption of a high-energy diet seems to be the most plausible common pathway for all of the risk factors that have been described.