鸡血清4型禽腺病毒与HH9亚型禽流感病毒亚型禽流感病毒、新城疫病毒混合感染的鉴定

试验对临床疑似血清4型禽腺病毒与H9亚型禽流感、新城疫混合感染鸡的病例进行了病毒分离与鉴定。通过接种鸡胚、血凝和血凝抑制试验、琼脂扩散试验、PCR鉴定,确定该病例为三种病毒混合感染。动物回归试验证明,1 000 ELD_(50)病毒量对2日龄SPF鸡致死率达到100%,剖检病变呈现典型心包积液-肝炎综合征,而H9亚型禽流感和新城疫病变特征不明显,说明混合感染中血清4型禽腺病毒病变非常典型,H9亚型禽流感和新城疫则呈现非典型病变。     

鹅副黏病毒甘肃地方毒株的分离和初步鉴定

鹅副黏病毒病是一种由鹅传播的新型急性传染病,该病与鸡感染新城疫具有相类似的临床症状和病理变化。2019年1月从甘肃某鹅场病鹅体内分离到一株副黏病毒,将病料处理后接种10日龄鸡胚,进行血凝试验(HA)和血凝抑制试验(HI),最后进行动物试验。结果表明:该病毒具有血凝活性,可以用标准的新城疫阳性血清抑制血凝活性,可能导致未接种新城疫免疫鸡胚的100%死亡。动物试验证明该病毒对鸡具有100%的发病率和致死率。     

加拿大发生高致病性禽流感

加拿大2007年9月28日向OIE报告，9月23日开始，萨斯喀彻温省Regina地区发生高致病性禽流感。疫情于9月27日确定，病原是H7N3禽流感病毒。诊断方法为临床检查和实验室检测，实验室检测由加拿大食品检验局（CFIA）境外动物疾病中心（NCFAD）负责，方法包括神经氨酸酶抑制试验、PCR、测序、竞争ELISA、病毒分离和血凝抑制试验，结果均为阳性。疫区位于Regina海滨的家禽饲养场，感染动物是肉种鸡，涉及易感动物49100例，病例560例，死亡560例，未予扑杀。[第一段]     

兔出血症病毒接种幼年兔及乳兔的人工感染试验

用兔出血症病毒人工接种一月龄与二月龄幼年仔兔，结果证实兔出血症病毒亦能感染并致死幼年仔兔，但感染类型与青成年兔的典型兔出血症不同，主要特征有病程延长，血凝价低或无血凝和黄疸肝炎等等。用兔出血症病毒特异性单克隆抗体建立的ＥＬＩＳＡ试验及反向间接血凝试验自血凝试验阴性的幼年兔各脏器均能检测到兔出血症病毒。人工感染乳兔虽未致临床病症，但扑杀检查见有坏死性肝炎病变和轻度肾小球性肾炎，且自肝肾等血凝检测阴性的病科中，用ＥＬＩＳＡ试验及细胞培养均可检测和分离到病毒。研究结果表明，血凝阴性并不能排除非典型兔病毒性出血症感染。     

猫泛白细胞减少症病毒的血凝及血凝抑制试验检测

猫泛白细胞减少症病毒是由细小病毒引起的传染病,能感染各种猫科动物。通过血凝及血凝抑制试验(HA/HI),检测猫细小病毒的抗原和抗体效价,从而确定一种简易、快速操作简单、敏感、准确的诊断方法,并为免疫程序提供可靠依据。     

犬细小病毒在乳猫肾细胞中的增殖动态

犬细小病毒可在乳猫肾细胞内增殖。感染细胞培养液中病毒血凝滴度呈增长趋势，用生物毒－亲和毒酶间接染色法观察细胞在感染后１４小时，胸核中即可出现特异性染色，至７２小时胞核染色明显，有的细胞 包浆中出现特异性染色，此时感染培养液可出现血凝现象。当浆染细胞培养液可出现血凝现象。当胞浆染色明显时，病毒血凝滴度也增高。至感染晚期，胞核几乎空染，围绕胞核有一深色胞浆区，些培养液的血凝滴度明显升高，两种方法所得结     

兔瘟强毒株的筛选和血清型鉴定——兔瘟H9组织灭活疫苗的研制

从安哥拉兔病死兔的肝脏中分离到一株病毒,经血凝试验、血凝抑制试验和动物交叉免疫保护试验,确定为兔瘟病毒(称RHDV-H)。     

金丝桃素蛋白络合物体外抗H5N1亚型禽流感病毒的活性研究

用鸡胚法进行了金照桃素蛋白络合物抗HSNI亚型禽流感病毒活性研究。分别采用了感染病素同时给药、给药后接种病毒、先感染病毒后给药三种方式，通过测定鸡胚尿囊液的血凝效价和计算药物对感染鸡胚的保护率，观察金丝桃素蛋白络合物的抗H5N1亚型禽流感病毒活性。实验结果表明，①药物在体外与病毒作用一段时间后不规则将其混悬液接种鸡胚，药物浓度在0.5mg/ml以上时，对感染鸡胚的保护率达100%。同时给药组的血凝效价显著降低，与对照组相比差异极显著；②在感染病毒前给药，药物浓度在2mg/ml以上时，对感染鸡胚的保护率达100%，药物组的血凝效价显著降低，与对照组相比差异极显著；③先感染病毒后给药，药物浓度在2mg/ml以上时，对感染鸡胚的保护率达88.9%，血凝效价明显隆低，与对照组相比差异显著。同时，在此种方式下，药物对病毒的抑制作用与药物浓度有一定依赖性，适当提高药物浓度，可以增强其抗病毒活性。     

狨猴副粘病毒感染

1999年夏季,在一个狨猴实验室中暴发急性呼吸道疾病,动物发病率达80％,死亡率约20％,病程在3-10天。在确定发病原因中,动物剖检只见肺脏病变,对4只死亡狨猴肺组织进行病毒分离,对分离物进行电子显微镜检查和血凝及血凝抑制试验,电     

猪细小病毒病的综合防治

猪细小病毒病是由猪细小病毒（PPV）引起的繁殖障碍病，该病主要表现为胚胎和胎儿的感染及死亡，特别是初产母猪发生死胎畸形胎和木乃伊胎，而其他年龄的猪感染后一般不见明显的临床症状（一）病原 猪细小病毒（PPV）为细小病毒科细小病毒属成员。病毒对热具有较强抵抗力，56℃48h、70℃2h病毒的感染性和血凝性均无明显改变，但80℃5min可使感染性和血凝活性均丧失。     

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.     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -