一例猪流行性腹泻病毒变异株导致仔猪腹泻的案例诊断

2020年11月初,福建南平某猪场仔猪开始发病,其临床症状以腹泻、呕吐等为主.为确定病因,猪场工作人员采集发病仔猪小肠等组织送至武夷山市农业农村局,工作人员分别检测猪流行性腹泻病毒、猪传染性胃肠炎病毒、猪轮状病毒和猪德尔塔冠状病毒等病原,结果仅在肠道组织中检测出PEDV(猪流行性腹泻病毒),且通过对该毒株的S1基因进行...     

猪流行性腹泻的防治

猪流行性腹泻是由猪流行性腹泻病毒(PE天V)引起的一种急性、高度接触性肠道传染病.该病主要引起猪水样腹泻、呕吐和伴随脱水为主要特征,对不同品种和不同年龄段的猪群均易感,但对哺乳仔猪,尤其是新生仔猪危害更严重.近年来,猪流行性腹泻在我国规模化猪场呈现爆发趋势,且流行性越来越广泛,已经成为规模化猪场重要的传染性病原之一,给广大养殖户带来巨大的经济损失.根据近年来猪流行性腹泻在规模化猪场的发病情况及流行特点,结合临床防控实践,重点论述了猪流行性腹泻的综合防治措施,以供大家参考.     

猪流行性腹泻的防治

猪流行性腹泻是由猪流行性腹泻病毒(PEDV)引起的一种急性、高度接触性肠道传染病.该病主要引起猪水样腹泻、呕吐和伴随脱水为主要特征,对不同品种和不同年龄段的猪群均易感,但对哺乳仔猪,尤其是新生仔猪危害更严重.近年来,猪流行性腹泻在我国规模化猪场呈现爆发趋势,且流行性越来越广泛,已经成为规模化猪场重要的传染性病原之一,给广大养殖户带来巨大的经济损失.根据近年来猪流行性腹泻在规模化猪场的发病情况及流行特点,结合临床防控实践,重点论述了猪流行性腹泻的病原体,诊断以及流行性防治措施做了详细的阐述,以供大家参考.     

新生仔猪流行性腹泻的综合防控

猪流行性腹泻(PED)是一种烈性肠道传染病,其重要病原为猪流行性腹泻病毒(PEDV)。笔者结合多年实践工作经验总结了PED的流行特点和诊断要领,同时提出了紧急处理、强化猪场生物安全和免疫接种、注重母猪与新生仔猪的精细化管理等综合防控措施。     

仔猪猪流行性腹泻病毒与大肠杆菌混合感染的诊治

仔猪腹泻现象在猪场时常发生，其主要传染性因素的病原分为病毒和细菌两类。猪流行性腹泻病毒是最主要的病毒病原，而大肠杆菌则是重要的细菌病原。当猪流行性腹泻病毒和大肠杆菌混合感染时，会给猪场造成严重的经济损失。本文通过一例仔猪猪流行性腹泻病毒和大肠杆菌混合感染的病例，从发病情况、剖检变化、实验室诊断、药敏试验、防治等方面进行阐述，旨在为临床上防控这两种疾病提供参考。     

猪流行性腹泻病毒S基因序列分析

根据猪流行性腹泻病毒S基因序列设计引物,应用RT-PCR方法从广东省某猪场采集的初生仔猪腹泻样品检测猪流行性腹泻病毒,并将其克隆测序分析。结果表明,病料样品中有猪流行性腹泻病毒,S基因与KNU-0801、KNU-0901亲缘关系最近,处于同一个分支;与弱毒疫苗株CV777的S基因亲缘关系较远,处于另外一个分支。     

猪流行性腹泻病毒引起仔猪腹泻的诊断

为了对贵州省某猪场发生的仔猪腹泻疫情进行病原学诊断,采用细菌分离培养、PCR及RT-PCR方法分别对采集的病料进行了细菌、猪流行性腹泻病毒及其他3种病原检测。结果显示,猪流行性腹泻病毒检测样品中出现651 bp目的条带,其他几种病原检测均为阴性,细菌分离培养未见细菌生长。结果表明,此次仔猪腹泻疫情的主要病因为猪流行性腹泻病毒感染。     

常见引起仔猪腹泻的病原学特点

2010年冬季至今,我国许多猪场都发生了非常严重的仔猪腹泻,造成了较大的经济损失。传统的致仔猪腹泻的病毒主要有3个：猪传染性胃肠炎病毒（porcine transmissible gastroenteritis virus,TGEV）、猪流行性腹泻病毒（porcine epidemic diarrhea virus,PEDV）和轮状病毒（porcine rotavirus,RV）,以及主要由上述3种病原引起的协同致病和混合感染,文中就引起常见仔猪腹泻的病原作简要综述。     

河南省南阳市某猪场一例猪流行性腹泻的实验室诊断

为对南阳市某猪场发生腹泻的病原进行鉴定,结合猪场发病情况、临床症状、剖检病理变化进行分析,并运用HE染色、RT-PCR等实验室技术综合判定。结果显示,某场新生仔猪发病率100%,临床表现为严重呕吐、腹泻且病死率较高,肠道组织切片发现空肠绒毛脱落、回肠细胞碱性粒子变多,RT-PCR结果显示猪流行性腹泻病毒(PEDV)阳性,提示本次某猪场腹泻主要是由猪流行性腹泻病毒感染造成的。     

猪流行性腹泻病毒病的诊治

山东省博兴县某规模猪场新生仔猪发生了一起以严重腹泻、脱水、呕吐为主要特征的疫病,通过发病情况、临床症状、病理变化等临床诊断以及RT-PCR等实验室检测,最终确定致病原为猪流行性腹泻病毒。通过采取系列针对性治疗措施,病情得到了有效控制。     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.