鸡毒霉形体人工感染肉用仔鸡后呼吸系统的病理形态学观察

７日龄健康肉用仔鸡气囊接种毒霉形体ＨＳ２心株,３－５ｄ后出现典型的ＭＧ感染症状,其呼吸系统发生一系列病理组织学变化。采集感染鸡及对照鸡的气管经固定,脱水,临界点干燥,镀金后置于扫描电镜下观察,可见感染鸡气管粘膜明显水肿,纤毛部分或全部脱落等,而对照组鸡气管则无任何病变;光镜下可见感染鸡的气管粘膜水肿增厚１－２倍,粘膜下层单核白细胞聚集,其间有数量不等的淋巴细胞集团,粘液细胞减少或消失;气囊粘膜水肿     

禽副粘病毒2型(PMV-2)致病性的研究

7日龄SPF鸡经滴鼻、点眼感染PMV-2，可引起轻微的呼吸道症状，病理组织学观察可见气管粘液分泌亢进和少量的淋巴细胞浸润。PMV-2与传染性支气管炎（IBV）或鸡毒支原体（MG）协同感染比单纯感染这三种病原的任何一种均呈现更严重的呼吸道症状，病理组织变化呈气管纤毛部分或全部脱落，气管粘膜上皮细胞不同程度的变性、脱落。固有层和粘膜下层严重水肿，有大量淋巴细胞、巨噬细胞和异嗜细胞浸润。SPF雏鸡感染PMV-2后的不同时间检查病毒在鸡体内的分布规律，结果表明，PMV-2在法氏囊中大量分布；气管、肺、胸腺中有较多病毒；大脑、脾和肾脏只有少量病毒存在。上述实验结果揭示PMV-2感染SPF雏鸡致病性较弱，PMV-2在鸡呼吸道综合征中起一定作用。     

鸡传染性喉气管炎的病理学研究

本研究对１４ 周龄的４２ 只 Ｓ Ｐ Ｆ鸡经气囊感染鸡喉气管炎病毒，通过病理组织学和扫描电镜检查，对不同感染阶段试验鸡进行研究。试验结果表明：感染后１２ｈ 气管粘膜淋巴细胞开始增生，以后逐渐增多，在８～９ ｄ 时逐渐减少，１２ ｄ 时基本降到原有水平；感染后２４ ｄ 气管粘膜上皮细胞开始形成合体细胞，３～４ ｄ 时普遍转变为合体细胞，并坏死脱落，６～７ ｄ 时出现再生，１２ ｄ 时基本恢复原有结构；腺体细胞在感染后坏死最早最严重，腺体细胞也是包涵体形成最早的细胞；在感染１２ ｄ时，气管粘膜上皮细胞纤毛项端开始融合并缩短，随后融合加剧，最终变成颗粒状或断裂脱落，上皮细胞表面裸露。除气管的病变外，肺脏发生支气管炎及出现核内包涵体，脾脏淋巴细胞，巨噬细胞增生及坏死，胸腺和法氏囊淋巴细胞增生及轻度坏死等变化。     

鸡传染性喉气管炎气管粘膜扫描电镜观察

对１４周龄的４２只ＳＰＦ鸡经气囊感染鸡喉气管炎病毒，通过扫描电镜观察，对不同感染阶段试验鸡的气管粘膜病变情况进行了研究。结果表明：感染后１～２ｄ时，气管粘膜上皮细胞纤毛顶端部分融合，逐渐变短；３～４ｄ时，纤毛断裂、脱落，上皮细胞裸露，部分融全成合胞体细胞，并见少量白细胞渗出；５～１０ｄ时，纤毛大部分溶解、消失，粘膜上皮细胞坏死、溶解、脱落，大量炎性渗出物和炎性细胞渗出。     

鸡毒霉形体病的防制

禽霉形体的众多血清型中，最重要的是鸡毒霉形体(MG)、鸡滑液囊霉形体(MS)和火鸡霉形体(MM)，尤其是MG的感染很普遍。MG引发的症状主要在呼吸系统，主要病变在气管和气囊。单纯的MG感染，在正常的饲养管理条件下，常不表现症状，呈隐性经过，一般只有轻微的呼吸道症状，死亡率10％-30％。肉鸡感染后生长发育受阻，体重减     

鸡霉形体病的防控

禽霉形体的众多血清型中,最重要的是鸡毒霉形体(MG)、鸡滑液囊霉形体(MS)和火鸡霉形体(MM),尤其是鸡毒霉形体感染很普遍。鸡毒霉形体引发的症状主要在呼吸系统,主要病变在气管和气囊。单纯的鸡毒霉形体感染,在正常的饲养管理条件下,常     

鸡败血霉形体病的诊治

病因饲养管理不善，鸡群拥挤，鸡舍通风不良，病原微生物或寄生虫侵袭及应激，均可诱发本病流行。临床症状病鸡流鼻液，打喷嚏、炎症延至下呼吸道时见气喘，有气管罗音、咳嗽、眶下窦蓄积渗出物，使眼睑肿胀、眼球突出、失明，蛋鸡产蛋率下降。病理剖检喉头、气管、鼻腔内有渗出物多数鸡眶下窦肿大，可见黏液及干酪样物，气囊混浊，囊壁增厚，肺充血，多数鸡可见气囊、肺有干酪样物。有合并感染的病鸡，腺胃、肝脏、肠道及心脏有出血变化，有的鸡关节肿大，滑膜液增多。诊断先将玻板抗原用含０．２５％石炭酸的缓冲生理盐水稀释２０倍，然后…     

鸡气囊炎的发生与防治

传染性气囊炎是近几年来新出现的流行性疾病，病鸡在治疗时表现出严重的耐药性，普通抗呼吸系统感染的药物无效，该病的病程长，危害大，临床上典型剖检症状为鸡气囊壁增厚，气囊内有黄白色干酪样渗出物，在胸气囊和腹部气囊症状尤为明显。     

鸡传染性喉气管炎与支原体混合感染的诊治

１　流行情况１９９９年２月２０日，某市某养鸡场饲养的１０００只１１０日龄商品蛋鸡，发现有个别的呼吸困难等症状，畜主用氟哌酸、氨苄青霉素治疗后无明显效果，第二天蔓延全群并出现死亡。２　临诊症状病鸡精神沉郁，食欲减少，呼吸困难，张口伸颈，咳嗽，眼睑肿胀，眼内流出粘液性渗出物，有的流鼻汁，鼻孔周围污染饲料，病鸡频频甩头并发出咳声，拉绿色稀薄的粪便。３　病理变化病鸡眼结膜发炎，喉头出血，气管粘膜增厚有出血点，气管内积满淡黄色粘液，胸气囊灰色混浊、气囊内有混浊的渗出物，肠粘膜水肿、出血。４　实验室诊断４．…     

鸡轮状病毒感染的病理形态学观察

为确定鸡轮状病毒感染的病理变化特点，对自然发病和人工发病轮状病毒感染鸡进行了病理学研究。结果表明，该病特征性的病理剖检变化为肠黏膜脱落出血，呈卡他性炎症表现。特征性组织学变化为小肠绒毛显著缩短，肠腺深度增加；除肠绒毛缩短外，肠上皮还变为扁平或立方形，并伴发坏死、脱落，黏膜充血、水肿与淋巴细胞浸润。电镜观察，肠黏膜上皮细胞的线粒体肿胀，嵴变粗，排列紊乱；粗面内质网及滑面内质网均扩张呈圆形，粗面内质网表面的核糖体部分脱落，胞浆内游离的核糖体减少。     

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.