布病的预防、控制及治疗

本文针对布病病原进行分析,探讨布病流行特点及发生症状,并进一步对布病病理变化进行剖检,结合流行病学接触史、临床症状体征和实验室检测结果综合诊断布病,提出有效防治措施.     

兽医系统实验室如何有效开展内部审核

为了解决兽医系统实验室普遍存在的管理体系文件与实验室管理实际工作不相适应的问题,笔者通过对近年来开展的辽宁省市县兽医系统实验室培训、考核、资质认定评审等工作进行总结分析,对导致该问题的原因进行调查分析。结果表明:实验室不能有效开展内部审核工作、实验室领导层不够重视、实验室日常运行监管措施不到位等因素是导致该问题的原因;同时笔者对兽医系统实验室考核、检验检测机构资质认定、认可相关法规准则规范等文件中关于内部审核工作要求进行解读,结合笔者在兽医系统实验室现场考核、资质认定评审工作及实验室日常运行管理工作中的经验体会,对兽医系统实验室内部审核的目的、组织、实施、后续措施及验证等事项进行了分析。     

对济南某羊场青贮饲料中毒的调查

[目的]2013年8月21日至9月6日,济南市某羊场出现不明原因羊只持续死亡的病例,本次调查的目的是为了发现疾病暴发的主要原因及其可能的风险因素。[方法]通过现场问卷调查及实验室检测结合的方法进行研究。[结果]调查及实验室检测结果显示该羊场青贮饲料饲喂过多,实验室检测鉴定到魏氏梭菌,针对调查发现的问题,提出了具体防控建议,采取措施后迅速有效控制了疫情。[结论]综合调查、实验室检测结果及防控措施实施的有效性推断该羊场本次疾病暴发的主要病因是青贮饲料饲喂过多引起酸中毒,造成羊群群体发病,魏氏梭菌病的继发感染是羊只发生死亡的重要因素。     

双峰驼胰腺炎的临床病理学研究

对长沙动物园２峰病死驼进行了临床病理学研究，根据死驼的临床表现、病理及组织学变化，结合实验室酶学检测，推断２峰双峰驼死于急性胰腺炎。     

1例猪瘟和猪繁殖与呼吸综合征混合感染的诊治

为确诊某规模化猪场发生的疫病,并对致病原加以确定,通过患猪发病情况、临床症状、剖检病变,结合实验室检测结果,综合分析判定该规模化猪场的疫情是猪瘟和猪繁殖与呼吸综合征混合感染,经紧急预防接种和选择对致病原高敏的药物治疗等相关措施后,有效控制了猪场疫情。     

湖南省非洲猪瘟检测实验室能力建设现状调查

为了解湖南省非洲猪瘟检测实验室能力水平,采用问卷调查、能力比对、现场调查等方式,对实验室类型、数量、仪器设备、人员配置、检测能力比对、运行情况、生物安全措施等开展全面调查。问卷及现场调查显示:湖南省具备非洲猪瘟检测能力实验室179个,其中系统内兽医实验室仅37个,检测力量薄弱,难以满足当前非洲猪瘟防控需要;屠宰企业实验室120个,但实验室条件简陋、人员配置不合理,检测结果难以有效保障;实验室仪器设备与检测试剂来源多样,缺少统一判定标准,结果准确率低;实验室质量管理体系及生物安全管理体系不完善,监管不规范。能力比对显示:参与完成能力比对的实验室150个,检测结果全部符合的实验室78个,实验室检测质量堪忧;屠宰企业实验室存在大量假阴性结果,疫病传播风险大。这提示湖南省虽拥有一批非洲猪瘟检测实验室,但整体检测水平不高,检测能力和实验室生物安全水平亟待加强。     

以一蓝耳病引起母猪流产病例谈兽医诊断

实验室诊断技术的普及给兽医诊断带来了便利,但过分依赖实验室诊断会让兽医在临床过程中忽视对疾病流行病学、示病症状和病变等临床特征的观察,弱化一线兽医的临床诊断能力。如果实验室诊断数据不结合临床特征来解读,容易造成误诊。本文中,笔者结合一起蓝耳病引起母猪流产的病例来阐述兽医诊断的思路。     

一例保育仔猪链球菌病的诊治

为查明甘肃省临夏县某猪场保育前期发病仔猪的病因，根据发病情况、临床症状、剖检病变及实验室检测，诊断为关节炎性链球菌病，采取相应防控措施后，疾病得到了有效控制。     

一例藏香猪混合感染猪流行性腹泻病毒与圆环病毒2型的报告

2016年3月四川九寨沟某藏香猪养殖基地出现10余例仔猪死亡案例,临床症状主要表现为呕吐,腹泻,水样稀便及消瘦,病程短,病死率高,呈典型病毒病症状。剖解发现小肠大面积充气,肠壁明显变薄,肠系膜淋巴结充血肿大,肾脏有大量出血点,腹股沟淋巴结充血肿大。采集病料进行实验室RT-PCR、PCR检测,结果为猪流行性腹泻病毒和圆环病毒2型阳性。结合临床症状、病理解剖特征及实验室检测结果,确诊为猪流行性腹泻病毒与圆环病毒2型混合感染。     

实验室检测结果的解读

随着我国动物疫病的复杂化,实验室检测成为确认疫病的重要手段,而对实验室检测结果的准确解读,可为疫病的科学防控提供强有力的技术支持。本文对实验室检测项目、实验室的资质要求和动物免疫抗体低下的主要原因进行了综述,确定主要因子,及时采取补救措施,保障动物防疫安全。     

The laboratory as an aid to clinical diagnosis

The clinician may use the clinical pathology laboratory as a valuable aid to diagnosis and management, for the assessment of response to treatment, and in preventive medicine programs. Each "link in the chain," that is, sample selection, collection, handling, analysis, result reporting, and interpretation must be carefully and efficiently managed, using an informed combination of art and science, to provide a useful endpoint. This general introduction precedes more specific and detailed articles.     

Laboratory test descriptions for bovine respiratory disease diagnosis and their strengths and weaknesses: Gold standards for diagnosis,do they exist?

The diagnosis of bovine respiratory diseases (BRD) poses significant challenges to the clinician as there are numerous infectious etiologies, operating singly or most often in combination. Clinical signs alone may not be diagnostic and the diagnostic laboratory is often used to assist the clinician. Recently many molecular-based tests have been taken from the research laboratory to the veterinary diagnostic laboratory. This review describes the “traditional tests” and several “molecular tests” and discusses the benefits and limitations of the tests and their interpretation. Clinicians should consult with their diagnostic laboratory regarding the interpretation of the test results. The rate of development and use of molecular diagnostic tests have outpaced validation, standardization, and standards for interpretation relative to their use in BRD diagnostics.     

Diagnosis of feline viral infection

A diagnosis of a specific viral disease in the cat involves a combination of an accurate history, careful observation of disease signs, demonstration of characteristic clinical pathologic changes, and isolation or identification of the virus. Isolation or identification of a virus from the patient does not establish that the disease observed was caused by the virus so isolated or identified; correlation and proper interpretation of all findings are necessary to establish a diagnosis. Virus identification may involve office laboratory tests, such as cytology or ELISA, or more specialized procedures. Whether specimens are to be sent out for specialized tests or office laboratory procedures are to be used, the veterinary practitioner must not only know what specimens are required but must also understand the test and be able to properly interpret the results in light of the patient's observed condition.     

The value of anion gap and osmolal gap determination in veterinary medicine

Introduction Evaluation of the anion gap and the osmolal gap has become routine in many medical institutions. Both calculations take little time, are essentially without cost, and have proven valuable in assessing a variety of clinical conditions. The wide range of acid-base and electrolyte abnormalities encountered in veterinary medicine makes assessment of anion and osmolal gaps a potentially valuable addition to veterinary clinical pathology. Eight months' experience with determination of calculated gaps at the New York State College of Veterinary Medicine has proven this to be the case. While both calculations are merely aids in the interpretation of clinical and laboratory data, the diagnostic value of the anion gap and the prognostic value of the osmolal gap is readily apparent. Both calculations can also play an important role in quality control monitoring of acid-base and electrolyte determinations.     

A practitioner's guide to understanding equine infectious disease diagnostics in the United Kingdom. Part 1: How to optimise sampling approaches and a guide to agent detection testing methods

Diagnostic testing is routinely performed by the equine clinician when dealing with suspected infectious disease cases and outbreaks. Optimal sample timing, choice and handling are fundamental to attain an accurate diagnosis, and a good understanding of laboratory-based sample analysis techniques, and their validation is necessary for effective diagnostic test result interpretation. This two-part series highlights the importance of interpreting results bearing testing limitations and specific clinical findings in mind, and on these foundations, the treating clinician should always be well placed to deal with equine infectious diseases. Part 1 in this series will provide a treating clinician with an overview of the importance of testing horses in infectious disease outbreaks and how this is achieved. The different laboratory testing options available for agent detection and their methods will also be discussed. Part 2 will summarise serological (antibody) testing techniques, sample processing (including how tests are performed and validated) and result interpretation.     

Current and emerging concepts in biological and analytical variation applied in clinical practice

A single laboratory result actually represents a range of possible values, and a given laboratory result is impacted not just by the presence or absence of disease, but also by biological variation of the measurand in question and analytical variation of the equipment used to make the measurement. Biological variation refers to variability in measurand concentration or activity around a homeostatic set point. Knowledge of biological and analytical variation can be used to facilitate interpretation of patient clinicopathologic data and is particularly useful for interpreting serial patient data and data at or near reference limits or clinical decision thresholds. Understanding how biological and analytical variation impact laboratory results is of increasing importance, because veterinarians evaluate serial data from individual patients, interpret data from multiple testing sites, and use expert consensus guidelines that include decision thresholds for clinicopathologic data interpretation. The purpose of our report is to review current and emerging concepts in biological and analytical variation and discuss how biological and analytical variation data can be used to facilitate clinicopathologic data interpretation. Inclusion of veterinary clinical pathologists having expertise in laboratory quality management and biological variation on research teams and veterinary practice guideline development teams is recommended, to ensure that various considerations for clinicopathologic data interpretation are addressed.     

Urinalysis interpretation: how to squeeze out the maximum information from a small sample

The urinalysis is an essential part of the diagnostic evaluation for all urinary and many metabolic diseases. Its assessment includes evaluation of physical characteristics (color, clarity, and volume), biochemical parameters (urine pH, blood, glucose, ketones, bilirubin, urobilinogen, and protein) and microscopic sediment evaluation (RBC, WBC, organisms, epithelial cells, crystals, and casts). Many of these parameters are influenced by collection method and therefore, it is essential to interpret accordingly. Knowledge of factors that can interfere with the accuracy of some test results can decrease improper interpretation. When all of these parameters are evaluated in combination with clinical signs, physical examination, thorough history and other laboratory tests, a diagnosis will often be attained.     

Objective interpretation of bovine clinical biochemistry data: application of Bayes law to a database model

With the advent of animal-side biochemistry analysers in veterinary practice, the requirement for ready access to reliable means for interpretation of the results is of increasing importance. At the University of Glasgow Veterinary School (GUVS), a large computerised hospital database containing extensive clinical, laboratory, and pathological information has been maintained. A retrospective study was undertaken to investigate plasma biochemistry results and corresponding post mortem diagnosis data from 754 unwell cattle which had presented to GUVS over the study period. Initial analysis of the clinical biochemistry data from this unwell population revealed that the parameters did not follow a normal distribution. This finding suggested that the accepted reference range method for the interpretation of clinical biochemistry data may provide limited information about the unwell animal. By applying a combination of percentile analysis and conditional probability techniques to the hospital data, the development of a means of clinical biochemistry interpretation was developed whereby a clinician could determine whether a value was abnormal, the degree of abnormality, and the most likely associated diseases. For example, a urea value of 30 mmol/1 lay within the top 5% of results, and one of the most common diseases associated with this urea value was pyelonephritis. Furthermore, a Bayesian approach allowed the quantification of the relationship between any plasma biochemistry value and disease through the generation of a ratio termed the ‘biochemical factor’. Using the same example, given a urea value of 30 mmol/1, pyelonephritis was eight times more likely than before any biochemistry information was known. The results from the study were used to form the basis of a software system which may ultimately be used by the clinician to aid in the recognition, treatment and prevention of disease in the veterinary domain.     

Evidence‐Based Medicine: The Design and Interpretation of Noninferiority Clinical Trials in Veterinary Medicine

Noninferiority trials are clinical studies designed to demonstrate that an investigational drug is at least as effective as an established treatment within a predetermined margin. They are conducted, in part, because of ethical concerns of administering a placebo to veterinary patients when an established effective treatment exists. The use of noninferiority trial designs has become more common in veterinary medicine with the increasing number of established veterinary therapeutics and the desire to eliminate potential pain or distress in a placebo‐controlled study. Selecting the appropriate active control and an a priori noninferiority margin between the investigational and active control drug are unique and critical design factors for noninferiority studies. Without reliable historical knowledge of the disease response in the absence of treatment and of the response to the selected active control drug, proper design and interpretation of a noninferiority trial is not possible. Despite the appeal of conducting noninferiority trials to eliminate ethical concerns of placebo‐controlled studies, there are real limitations and possible ethical conundrums associated with noninferiority trials. The consequences of incorrect study conclusions because of poor noninferiority trial design need careful attention. Alternative trial designs to typical noninferiority studies exist, but these too have limitations and must also be carefully considered.