一例猪蓝耳病与猪圆环病毒病混合感染的诊断报告

2019年河南某猪场暴发了一起以仔猪消瘦,大批死亡为特征的传染病。为了确定致病病原,研究团队对患病猪场进行了流行病学调查,根据临床症状和病理剖检确定了疑似病原,再通过对猪瘟病毒(CSFV)、猪伪狂犬病毒(PRV)、高致病性猪蓝耳病病毒(PRRSV)、猪圆环病毒2型(PCV2)4种疑似病原进行PCR和RT-PCR实验室诊断,最终确诊为猪蓝耳病病毒与猪圆环病毒2型的混合感染。     

猪木乃伊胎病原体混合感染的多重PCR诊断

2013年11月,贵州省都匀市某猪场发生了一起母猪流产、产死胎为特征的疾病,为确诊该猪场病原诊断类型,试验采用猪繁殖障碍性病毒性疫病六重PCR检测方法对送检木乃伊胎病料进行了猪伪狂犬病毒(PRV)、猪细小病毒(PPV)、猪圆环病毒2型(PCV2)、猪繁殖与呼吸综合征病毒(PRRSV)、猪瘟病毒(CFSV)和乙型脑炎病毒(JEV)的快速检测,结果表明该猪场送检病料存在PCV2和JEV两种病毒的混合感染。     

2016年山东省猪病毒性疫病的病原学检测

为了解2016年山东省几种主要猪病毒性疫病的流行情况,采用荧光定量RT-PCR或PCR方法,对山东省部分猪场送检的730份病料进行了病原学检测。结果检出248份阳性病料,样品个体阳性检出率由高到低的病原依次为猪圆环病毒2型（13.02%）、猪蓝耳病病毒（10.41%）、古典猪瘟病毒（8.08%）、猪流行性腹泻病毒（7.26%）、猪伪狂犬病毒（3.84%）、猪轮状病毒（1.65%）、猪传染性胃肠炎病毒（0.14%）;样品混合感染阳性率为8.08%,以猪蓝耳病病毒和猪圆环病毒2型混合感染最为常见（3.02%）。本次病原学检测为山东省猪场病毒性疾病的综合防控提供了数据参考。     

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。     

猪附红细胞体和猪圆环病毒、猪瘟混合感染

2006年10月，江苏盐城某猪场发生以发热、皮肤出血、下痢和急性死亡为特征的急性疾病。经临床诊断、病理剖解、实验室检验，确诊为猪圆环病毒、猪瘟病毒和猪附红细胞体引起的急性混合感染。     

猪细小病毒病的诊治

作者对某猪场的病死猪进行临床症状观察、病理剖检及实验室诊断,通过病毒的分离培养及鉴定,确诊病死猪为猪细小病毒感染。鉴于养殖场中该病的存在及对养猪业的危害,建议加强对猪细小病毒的诊断及监控。     

一例高致病性蓝耳病病毒、圆环病毒2型和副猪嗜血杆菌混合感染的诊断

目前,猪场疫病混合感染的现象普遍存在,给我国养猪业造成了巨大损失。2013年10月,广西省某集约化猪场约6周龄猪群发生以高热、皮肤发绀、呼吸困难、关节炎为主要特征的传染病。根据发病情况、临床症状、剖检变化并结合实验室诊断方法进行综合诊断,最终结果显示,导致该猪场大规模发病并死亡的主要病原包括高致病性猪蓝耳病病毒、猪圆环病毒2型和副猪嗜血杆菌,是典型的混合感染导致大规模发病及死亡的案例。     

猪圆环病毒、巴氏杆菌及副猪嗜血杆菌混合感染的诊治

重庆某猪场发生以发烧、呼吸困难、关节肿胀为主要症状的疫情,给猪场造成了很大损失,通过现场诊断和实验室病原学检测,确诊为猪圆环病毒、巴氏杆菌及副猪嗜血杆菌混合感染。经药敏试验筛选出丁胺卡那霉素等敏感药物,采取以控制细菌感染为主的综合措施控制了疫情。     

猪流行性腹泻病毒和大肠杆菌混合感染的综合防治

通过对某规模猪场发病猪临床巡视、剖检变化,对病猪样品进行细菌学检测和猪传染性胃肠炎病毒、猪流行性腹泻病毒、猪轮状病毒三重实时荧光RT-PCR检测,确诊为猪流行性腹泻病毒和大肠杆菌混合感染。药敏试验结果显示:大肠杆菌对卡那霉素、丁胺卡那极敏,对庆大霉素、氯霉素等耐药。通过彻底清洁消毒、全群治疗、母猪返饲等综合防治措施,该病得到了有效控制。     

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.     

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.     

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     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.