2014年广西部分地区常见猪群疫病感染情况监测分析

为探明2014年广西猪群主要疫病的感染情况,本研究从发病猪场和屠宰场采集猪组织样品共325份,应用RT-PCR方法检测猪瘟病毒(CSFV)、猪繁殖与呼吸综合征病毒(PRRSV)、猪流行性腹泻病毒(PEDV),并应用PCR方法检测猪圆环病毒2型(PCV2)和猪伪狂犬病病毒(PRV)。结果发现,发病猪场中,这5种病毒感染率分别为12.00%、28.57%、19.43%、53.71%和9.71%,而屠宰场的感染率分别为5.33%、2.67%、5.33%、59.33%和11.33%。对猪群混合感染情况分析发现,PCV2和其他病原的混合感染率最高。其中,发病猪场二重感染最高的为PRRSV+PCV2,达到11.43%,其次为PEDV+PCV2、CSFV+PCV2和PCV2+PRV,阳性率分别为5.71%、4.00%和4.00%;三重感染率最高的为PRRSV+PEDV+PCV2以及PRRSV+PCV2+PRV,阳性率均为2.29%。屠宰场二重感染最高的是PCV2+PRV,达到3.33%;三重感染最高的是CSFV+PCV2+PRV,阳性率为0.67%。结果表明,在发病猪场和屠宰场中,PCV2的感染率最高,且常与其他病原发生混合感染,PRV感染率呈上升趋势,加强对这2种病毒的监控对控制广西地区猪群发病具有重要意义。     

安徽省猪呼吸道疾病五种病原的分离与鉴定

猪呼吸系统疾病目前是困扰我国养猪业主要疾病之一。为了弄清安徽省猪呼吸道疾病主要致病微生物,本研究利用细菌学鉴定技术、RT-PCR技术对2010年-2011年安徽省皖南、皖中、皖北地区采集的180份呼吸障碍性病(死)猪病料进行了猪繁殖与呼吸综合征病毒、圆环病毒2型、链球菌、巴氏杆菌、副猪嗜血杆菌等5种病原进行了分离鉴定。结果显示,猪繁殖与呼吸综合征病毒感染率高达68%,圆环病毒2型感染率高达83.3%;猪繁殖与呼吸综合征病毒与圆环病毒2型混合感染率达27.8%,猪链球菌感染率为22.8%。结果提示,猪繁殖与呼吸综合征病毒缺失株、圆环病毒2型、链球菌的普遍感染是近年安徽省猪呼吸道疾病的重要致病病原,研究结果为安徽省今后猪群呼吸道疫病防控策略的制定提供了参考依据。     

江苏地区副猪嗜血杆菌病流行现状调查

为了分析副猪嗜血杆菌病在江苏区域流行现状,选取江苏省不同地区疑似发病猪场,进行临床症状分析、病理学变化观察、病原分离鉴定、血清学检测等试验。结果显示:317份病料中副猪嗜血杆菌(Haemophlius parasuis, HPs)阳性率为11.54%～27.55%,平均感染率为20.50%;从发病猪场共分离到HPs 43株,其中优势血清型为12型(37.21%)、4型(16.28%)和5型(13.95%),未定型菌株9株(20.93%),分型菌株占所有菌株的79.07%;PCR检测显示,HPs与猪圆环病毒(PCV2)、猪伪狂犬病毒(PRV)存在混合感染现象,感染率达30.77%。研究结果为江苏地区副猪嗜血杆菌病的防制提供了参考。     

猪圆环病毒2型继发感染大肠杆菌和副猪嗜血杆菌的诊断

江苏某猪场断奶仔猪发生以体温升高为主要临床特征的传染病,发病率和死亡率均较高。本研究对其送检的病死猪样本进行了病原学检测和病原的分离与鉴定,结果从其内脏样本中检测和分离到多种病原。通过细菌学方法分离到副猪嗜血杆菌和大肠杆菌,通过病毒学方法分离到猪圆环病毒2型（PCV-2）。通过临床诊断、病理解剖和实验室确诊,综合判断该猪场感染了PCV-2,并继发感染了副猪嗜血杆菌和大肠杆菌,造成较大损失。     

一例猪圆环病毒病2型和大肠杆菌病混合感染的诊断

猪圆环病毒病是指以圆环病毒-2型（PCV2）为主要病原,单独或混合感染。它是断奶仔猪多系统衰竭综合征的主要病原,一般于断奶后2～3 d或1周发病,急性发病猪群中,病死率可达10%。大肠杆菌主要是一种条件性致病菌,其中以仔猪黄白痢最为常见。2016年3月份,某猪场1月龄仔猪突然发病,病死率较高,送检病猪3头进行病因诊断。为了解该规模化猪场疫病的感染状况,通过该猪场猪群发病情况及剖检病理观察,初步判断该猪场发病猪疑似为猪瘟病毒、猪圆环病毒2型或细菌感染,通过进一步分子生物学检测及细菌分离培养与鉴定,确诊该猪场发病猪为猪圆环病毒2型和大肠杆菌混合感染。     

上海地区发病猪群猪圆环病毒2型阳性样本中其他病原混合感染状况调查

本研究对2009年至2011年上海地区发病猪群内脏样本进行猪圆环病毒2型(Porcine circovirus,PCV2)检测,对PCV2阳性样本进行2a/2b分型检测,并对PCV2阳性样本进行其他病原混合感染状况调查。上海地区发病猪群PCV2阳性率平均为54.34%,以PCV2b单纯感染为主。在PCV2阳性样品中,其他病毒混合感染率平均达到60.2%,细菌混合感染率达到61.22%,病毒与细菌同时混合感染率为41.84%,平均混合感染率达到53.06%。研究表明,上海地区发病猪群PCV2阳性样本与其他病原混合感染比例较高,病毒主要以PRRSV为主,细菌主要以大肠杆菌、沙门氏菌、链球菌及副猪嗜血杆菌为主;混合感染是导致猪群死亡的重要因素,也是当今上海地区猪群疫病的感染现状及发病模式。     

一例规模化猪场猪呼吸道疫病的诊治

2015年4—5月份,贵州省贵阳市某规模化猪场发生了猪呼吸道疫病,以体温升高、呼吸困难、胸膜炎、心包炎、关节炎为特征,发病猪死亡率达到80%。经过流行病学调查、临床症状、病理剖检、细菌分离鉴定、病毒核酸PCR鉴定,诊断为猪繁殖和呼吸综合征病毒、副猪嗜血杆菌和猪传染性胸膜肺炎放线杆菌混合感染。根据诊断结果对该规模化猪场采取综合防治措施,疫情得到有效控制。     

仔猪副猪嗜血杆菌的分离鉴定及耐药性检测

为了了解海南藏族自治州共和县规模化猪场中仔猪副猪嗜血杆菌分离株的流行情况及对常用抗菌药的耐药情况。本试验于2022—2023年采集海南藏族自治州共和县规模化猪场中患疑似副猪嗜血杆菌病的仔猪鼻拭子、关节液、胸腔积液、肺脏等病料,共计283份。采用细菌分离鉴定、PCR方法对采集的病料进行副猪嗜血杆菌分离鉴定,采用人工感染小鼠试验验证分离株的致病性,采用纸片扩散法(Kirby-Bauer,简称K-B法)检测致病性副猪嗜血杆菌分离株对临床中常用抗菌药的耐药性。结果显示：从采集的283份病料中分离到128株副猪嗜血杆菌,通过致病试验显示,91株副猪嗜血杆菌能引起小鼠不同程度发病与死亡,为致病性菌株;分离的91株致病性副猪嗜血杆菌对磺胺间甲氧嘧啶、阿莫西林、氨苄西林等6种药物的耐药率为85.7%以上,对其他药物的耐药率为3.3%～25.3%,本研究为该地区仔猪副猪嗜血杆菌合理用药及防控提供参考。     

断奶仔猪多系统衰竭综合征相关病原混合感染的流行病学调查

为了解中国江苏省及周边地区猪场断奶仔猪多系统衰竭综合征(PMWS)相关病原的流行情况,本研究采用PCR方法,对2014年1月至2015年5月采自江苏、安徽及浙江等地猪场的125份健康猪样品和261份发病猪样品分别进行猪圆环病毒2型(PCV2)、猪繁殖与呼吸综合征病毒(PRRSV)、猪细小病毒(PPV)、输血性传播病毒(TTV)和类猪圆环病毒P1的检测。结果显示,所有样品PCV2、PRRSV、PPV、TTV1、TTV2和P1的阳性率分别为39.38%、21.76%、3.11%、15.80%、16.32%和10.10%,其中混合感染主要存在于PMWS的发病猪群,以PCV2与TTV2 (15.32%)和PCV2与PRRSV (11.87%)的混合感染为主。结果表明,江苏省及周边地区猪场普遍存在PMWS相关病原的混合感染现象,加大了PMWS相关病原的防控难度。     

PRV、PCV-2、PRRSV与HPs混合感染的核酸检测

为确定青海省某规模化发病猪场的发病原因,在临床诊断的基础上对采集的临床组织病料进行了13种常见病原体的核酸检测,并对检测结果进行了序列鉴定.结果表明,该发病猪场存在猪伪狂犬病毒、猪圆环病毒2型、猪繁殖与呼吸综合征病毒与副猪嗜血杆菌的混合感染.研究结果提示,利用分子生物学技术对发病猪场的病原进行快速鉴定,是病源快速诊断和防控的有效途径.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein