摄食PRRSV感染的猪肉对PRRS病毒传播风险的评估

本研究目的是确定在试验感染猪肌肉中多长时间能检测出猪繁殖与呼吸综合征病毒（PRRSV）和评估猪繁殖与呼吸综合征（PRRS）通过摄食经定量反转录聚合酶链式反应（qRT-PCR）鉴定为PRRS阳性的猪肉的传播风险。试验采集135头试验猪（试验组人工接种PRRSV,89头;阴性对照组46头）的血清、淋巴组织和肌肉（背最长肌）。接种后第28天～第202天,试验组中13头猪（14.6%）的肌肉样本出现qRT-PCR阳性,在其中4头猪的血清样本和3头猪的淋巴组织样本中分离到了PRRSV。另外,通过生物鉴定在该13头试验猪中6头的淋巴组织匀浆中检测到了该病毒。通过给13头3周龄的PRRSV阴性猪饲喂定量PT-PCR检测阳性的猪肉并利用定量PT-PCR检测监控该试验猪的PRRS感染情况,研究了PRRS的传播性。定量PT-PCR检测结果显示,食用PRRS阳性猪肉的试验猪没有感染PRRS。以上资料表明,定量PT-PCR在猪肉中检测到了非传染的PRRSV,通过食用PRRSV感染猪肉PRRSV没有极大的传播性。     

摄食PRRSV感染的猪肉对PRRS病毒传播风险的评估

本研究的目的是确定在试验感染猪肌肉中多长时间能检测出猪繁殖与呼吸综合征病毒（PRRSV）和评估猪繁殖与呼吸综合征（PRRS）通过摄食经定量反转录聚合酶链式反应（qRT-PCR）鉴定为PRRS阳性的猪肉的传播风险。试验采集135头试验猪（试验组人工接种PRRSV,89头;阴性对照组46头）的血清、淋巴组织和肌肉（背最长肌）。接种后第28天~第202天,试验组中13头猪（14.6%）的肌肉样本出现qRT-PCR阳性,在其中4头猪的血清样本和3头猪的淋巴组织样本中分离到了PRRSV。另外,通过生物鉴定在该13头试验猪中6头的淋巴组织匀浆中检测到了该病毒。通过给13头3周龄的PRRSV阴性猪饲喂定量PT-PCR检测阳性的猪肉并利用定量PT-PCR检测监控该试验猪的PRRS感染情况,研究了PRRS的传播性。定量PT-PCR检测结果显示,食用PRRS阳性猪肉的试验猪没有感染PRRS。以上资料结果表明,定量PT-PCR在猪肉中检测到了非传染的PRRSV,通过食用PRRSV感染猪肉PRRSV没有极大的传播性。     

猪瘟疫苗在猪圆环病毒2型阳性猪场的免疫效果观察

为了研究猪圆环病毒2型(PCV-2)感染对猪瘟疫苗免疫效力的影响,对PCR证实为PCV-2阳性的试验猪进行猪瘟疫苗的免疫,分别在免疫后第1、3、7、14、21、28和63天对试验猪进行猪瘟病毒(CSFV)和PCV-2的抗体检测。检测结果表明PCV-2阳性猪在猪瘟疫苗免疫后均未能产生有效的CSFV抗体,从免疫猪的血液和内脏组织中也未能检测到CSFV核酸。虽然只能从1头PCV-2阳性猪的血清中检测到PCV-2抗体,但是却能从全部实验猪的淋巴结中检测到PCV-2的核酸。试验猪的病理组织学观察和白细胞计数也表明PCV-2阳性猪的淋巴结呈典型的PCV-2感染的病理变化,且白细胞数量显著低于健康猪。表明PCV-2的感染会对猪的免疫系统造成损害从而抑制猪瘟疫苗的免疫效果。     

犬瘟热病毒自然感染宠物犬不同部位检出率的分析

本试验利用RT-PCR检测方法对犬瘟热病毒(CDV)自然感染宠物犬的不同部位样品进行检测,确定CDV在感染犬组织中的分布情况。对14只CDV阳性犬的血液、眼分泌物、鼻液、唾液、粪便和尿液进行检测,RT-PCR方法检出的阳性率分别为92.9%、85.7%、100%、85.7%、100%和66.7%,结果显示粪便和鼻液样品的检出率最高,检出率达100%,宜于作为检测对象取材。     

猪圆环病毒病的危害及综合防控

正猪圆环病毒病(PCVD)是由猪圆环病毒2型(PCV2)引起的猪传染性疾病。该病主要引起仔猪及生长育肥猪群的消瘦、生长不良、呼吸困难、腹泻、皮炎等症状,也会导致母猪的繁殖障碍。病猪和带毒猪是主要传染源,可经口腔、呼吸道感染不同日龄的猪群,少数孕猪感染后,可经胎盘垂直传染给仔猪,并且公猪的精液也可以带毒。病猪的鼻腔、扁桃体、气管、眼分泌物、粪便、唾液、尿液等均可检测到病毒,且在猪舍的地面、猪     

猪瘟病毒感染西藏小型猪致免疫器官损伤的组织病理学研究

为了研究CSFV感染对西藏小型猪的致病性及组织病理学方面的影响,将6头4月龄健康西藏小型猪随机分成2组,其中感染组4头,对照组2头。感染猪颈部肌肉注射CSFV石门株血毒(1×10~5TCID_(50)/头),对照组猪注射等体积生理盐水。CSFV接种后每天监测动物体温并观察临床症状,于CSFV感染后第9天剖杀全部试验动物,测定血液CSFV核酸载量,观察各组织器官病理变化并采集扁桃体、颌下淋巴结、脾脏、胸腺等免疫器官进行组织病理学研究。结果显示,CSFV感染后第2天猪只体温超过40.2℃,开始出现精神沉郁、食欲减退、便秘等临床症状;CSFV感染后濒临死亡时猪血液中病毒含量最高达1×10~(8.9)Copies/mL,最低含量为1×10~(5.2)Copies/mL。组织病理学结果显示,CSFV感染猪扁桃体间质、颌下淋巴结被膜和脾脏的淋巴滤泡周围可见大量出血及片状坏死,颌下淋巴结生发中心可见局部增生性变化,胸腺间质可见炎性细胞浸润。对照组猪血液CSFV核酸为阴性、病理和组织学切片未见异常。结果表明,本研究成功建立CSFV感染西藏小型猪的动物模型,CSFV感染西藏小型猪后对扁桃体、脾脏、淋巴结和胸腺等免疫器官造成损伤,使机体免疫功能降低。     

3ABC-ELISA检测口蹄疫野毒抗体时效性研究

为了验证3ABC-ELISA检测口蹄疫野毒感染抗体的时效性,用口蹄疫OZK/93、O/(XJ/10-11/MYA/98)病毒分别对3ABC-ELISA检测阴性的60头临床健康免疫猪和4头未免疫临床健康对照猪经肌肉注射接种.接种病毒第6天,对照猪全部发病,实验猪6头发病,其中对照猪3ABC-ELISA抗体全部为阴性,实验发病猪3ABC-ELISA抗体阳性1头,54头未发病猪3ABC-ELISA抗体阳性14头.试验结果表明,3ABC-ELISA检测口蹄疫野毒抗体具有时效性,建议在口蹄疫疑似病例确诊中优先采用病原学检测方法进行确诊,3ABC-ELISA检测方法可以用作野毒感染的追溯性调查.     

猪繁殖与呼吸综合征病毒接触感染仔猪模型的建立

为了建立猪繁殖与呼吸综合征病毒(PRRSV)接触感染模型,将易感仔猪与PRRSV人工感染仔猪在隔离器中同居饲养,每日观察记录体温变化和临床症状,定期采集血清和粪便样品,用荧光定量RT-PCR检测病毒血症和粪便排毒水平;对病死猪和试验结束迫杀猪进行剖检和肺脏组织病理学检查,并检测各器官病毒载量和组织分布。结果显示:接触感染仔猪出现高热和PRRS症状时间分别较人工接种猪推迟2~3d;第3天起血清检测PRRSV阳性,第10天病毒血症上升至较高水平(108.6拷贝/mL);第5天起粪便检测PRRSV阳性,第7天粪便排毒量上升至较高水平(103.9拷贝/0.1g);3头接触感染仔猪分别于同居后第12天和第13天死亡,较人工接种猪推迟1~2d,病死猪的主要器官病毒载量以及剖检和肺脏显微病理变化与人工接种病死猪相似。这些结果表明,本研究建立的接触感染仔猪模型可用于PRRS疫苗免疫效果评价。     

新型病毒抑制剂可减少古典猪瘟感染

5-[（4-溴苯基）甲基-2-苯基-5H-咪唑并[4,5-c]吡啶（BPIP）在体外具有抗病毒活性。研究人员分析了BPIP能否减少古典猪瘟病毒（CSFV）在感染仔猪体内复制。给8头SPF猪连续饲喂15天（混在饲料中）,每天75mg／kg。开始前1天用CSFV现地分离物感染。结果表明,BPIP处理猪发生短暂的一过性病毒血症（有1头仍阴性）和白细胞减少症（3头未发生）。在病毒血症高峰（感染后7天）的病毒滴度显著低于未处理猪（P=0．00005）,血液中病毒基因组荷载也显著降低（P〈0．001）。     

应用ELISA(双抗体夹心法)检测猪流行性腹泻病猪粪便中的病毒抗原

应用猪流行性腹泻(PED)—ELISA直接法(双抗体夹心法)对120头健康猪和5头猪传染性胃肠炎(TGE)病猪粪便标本进行检测,均不出现交叉反应;对15头PED病毒实验感染仔猪粪便标本检测,全部呈阳性;将对3(?)份ELISA阳性粪便标本和3份阴性标本的检测结果与电镜观察结果比较,其阳性符合率为97.37％,阴性符合率为100％;对在PED发病季节从不同地区采集的腹泻病猪粪便标本112份检测结果,阳性率为60.71％,而阴性反应的标本,绝大多数是在病愈后15～20d采集的。     

犬的急性胰腺炎

胰腺炎是胰腺因胰蛋白酶的自身消化作用而引起的,可分为急性和慢性两种。犬的急性胰腺炎以空发性前腹部疼痛、腹壁紧张、敏感、弓背,有时呈祈祷状、恶心、呕吐为特征。急性胰腺炎又分水肿型和出血坏死型两种,临床上多见水肿型。我院自2005年11月份到2006年11月份这一年中,共接诊胰腺炎病例30例,83Z的病例（24例）多为犬细小病毒感染或严重的肠道寄生虫感染后继发的急性水肿型胰腺炎,只有6例是暴饮暴食或饮食不当引起的原发性急性水肿型胰腺炎。     

Pathophysiology of acute laminitis

This article reviews research findings relating to the pathophysiology of acute laminitis in horses. The data presently available suggest that the onset of the condition may be due to constriction of the postcapillary vessels in the digit, leading to increased capillary hydrostatic pressure and movement of fluid into the interstitial space.     

Cytokines and acute phase proteins associated with acute swine influenza infection in pigs

This study set out to investigate the cytokines and acute phase proteins (APPs) associated with the acute stages of experimentally-induced swine influenza virus (SIV) infection in 3-week-old, colostrum-deprived, caesarean-derived piglets. The piglets were inoculated intratracheally with 10^7.5 50% egg infective dose [EID₅₀] Swine/Belgium/1/98 (H1N1) SIV and were euthanased at time-points between 0 and 120 h post-inoculation (PI). Broncho-alveolar lavage fluid (BALF), lung homogenates and sera were examined for inflammatory mediators by bioassay or ELISA. Interferon (IFN)-α, interleukin (IL)-6, IL-1 and tumour necrosis factor (TNF)-α peaked in BALF 24–30 h PI, when virus titres and the severity of clinical signs were maximal.Whereas IFN-γ and IL-12, but not IL-18, increased in tandem in BALF, serum cytokine concentrations were either undetectable or were up to 100-fold lower. The APP C-reactive protein (CRP) and haptoglobin peaked 24 h later than the cytokines and reached higher levels in serum than in BALF. In contrast, lipopolysaccharide (LPS)-binding protein (LBP) only increased in BALF. Lung virus titres tightly correlated with BALF IFN-α, IL-6, IL-1, TNF-α, IFN-γ and IL-12, as well as with serum IL-6, IFN-α and IFN-γ. Signs of disease correlated with the same cytokines in BALF and serum, as well as with BALF LBP and serum CRP. The findings suggest that IFN-γ and IL-12 play a role in the pathogenesis of SIV and that APPs are induced by cytokines. This influenza infection model may have value in assessing the therapeutic potential of cytokine antagonists.     

Approach to the acute abdomen

Acute abdominal pain is a clinical sign associated with several underlying disease processes, many of which can be life threatening. Abdominal pain requires efficient diagnostic evaluation to determine the appropriate course of treatment. Definitive treatment involves medical and/or surgical management. The emergency clinician must be well versed in the diagnostic approach to these patients to facilitate appropriate therapy.     

Probable lumbar acute non-compressive nucleus pulposus extrusion in a cat with acute onset paraparesis

A spinal cord lesion localised caudal to the L6 spinal segment was diagnosed in a 2-year-old female spayed domestic longhair cat with acute onset paraparesis. Magnetic resonance imaging findings were consistent with an acute, non-compressive nucleus pulposus extrusion of the L5-L6 intervertebral disc. The cat was successfully managed with supportive care, including cage confinement.     

The feline acute phase reaction

The acute phase reaction (APR) is a response to potentially pathogenic stimuli. It begins with the release of interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF)-alpha from inflammatory cells. These cytokines induce fever, leucocytosis and release of serum acute phase proteins (APPs). In this review, the characteristics of the feline APR are described. In cats with inflammatory conditions, fever is a common finding, with leucocytosis due to the release of cells from the marginal pool, followed by activation of myelopoiesis. Because excitement frequently causes leucocytosis in cats, a diagnosis of inflammation should therefore be supported by additional findings such as the presence of toxic neutrophils. The major APPs are serum amyloid A and alpha(1)-acid glycoprotein (AGP), which both increase a few hours after the inflammatory stimulus and remain elevated for as long as the inflammation persists. AGP plays an important role in the diagnosis of feline infectious peritonitis (FIP) and may also be useful also in studies of FIP pathogenesis.     

Diagnostic approaches to acute pancreatitis

Acute pancreatitis is a challenging medical condition, with the potential for high mortality and comorbidity in companion animal patients. The anatomic position and relationships of the pancreas make direct observation of pancreatic pathology difficult, so the diagnosis of pancreatic disease is typically based on the measurement of biochemical markers in serum and imaging studies of the abdomen. The digestive enzymes typically used in the diagnosis of pancreatitis, amylase and lipase, have poor sensitivity and specificity. Recently, pancreas specific lipases have been purified from dogs and cats, leading to the availability of specific immunoassays for these proteins that show great promise in the diagnosis of acute pancreatitis. After the diagnosis of acute pancreatitis is established, there is a need to assess the severity of the disease to give an accurate prognosis for the patient. This article will review currently available methods used to diagnose acute pancreatitis and the ability of these methods to assess accurately the severity of the disease.     

Treatment of acute adrenal insufficiency

Hypoadrenocorticism is caused by a lack of endogenous glucocorticoid and mineralocorticoid. These deficiencies can cause a myriad of clinical signs. This disease is uncommon and its clinical presentation is similar to many much more commonly recognized diseases such as renal failure and various gastrointestinal disorders. Severely affected patients may present in a life-threatening adrenocortical crisis, which is characterized by variable degrees of volume depletion and electrolyte abnormalities. The emergency clinician should maintain a high clinical suspicion for hypoadrenocorticism, as early recognition and rapid treatment of hypovolemia and electrolyte abnormalities can be lifesaving. The approach to emergency treatment of hypoadrenocorticism should be to recognize and treat life-threatening arrhythmias, replace intravascular volume and normalize perfusion, correct electrolyte abnormalities and hypoglycemia, administer glucocorticoids, and perform the adrenocorticotrophic hormone stimulation test for definitive diagnosis. Patients with this condition should have a favorable outcome when treated appropriately.