乙基环丙沙星对实验性感染猪链球菌病及水肿病的药效学研究

本文报道以国内新近研制的畜禽专用氟喹诺酮类抗菌药－－乙基环丙沙星（Ｅｎｒｏｆ－ｌｏｘａｃｉｎ），进行对实验性感染猪链球菌病及水肿病的药效学研究（２３０头猪）。试管两倍稀释法测得乙基环丙沙星对兰氏Ｃ群类马链球菌（Ｃ５５１２０）和猪大肠杆菌（Ｏ５４）的最小抑菌浓度（ＭＩＣ）分别是０．８及０．０５ｕｇ／ｍｌ。肌注给药对猪链球菌病和水肿病的实验性治疗结果表明，乙基环丙沙星低、中、高剂量组（分别为１．２５、     

二氟沙星对实验性感染猪支原体性肺炎及链球菌病的药效学研究

以试管两倍稀释法测得二氟沙星对猪肺炎支原体（ Ｆ１６ 株）和兰氏 Ｃ 群类马链球菌（ Ｃ５５ １ ２０ ）的最小抑菌浓度分别是０１６ｍ ｇ／ Ｌ及 １６ｍ ｇ／ Ｌ。肌注给药对猪支原体性肺炎及链球菌病的实验性治疗结果表明,低、中、高剂量二氟沙星组（２５、５、１０ｍ ｇ／ｋｇ）及蒽诺沙星组（２５ｍ ｇ／ｋｇ）用药 ５ 天（每隔 １２ 小时给药一次）对猪支原体性肺炎的治愈率分别是 ８０％ 、９０％ 、１００％ 及９０％ ;而支原体感染对照组的自愈率为１０％ 。低、中、高剂量二氟沙星组及蒽诺沙星组（２５ｍ ｇ／ｋｇ）用药 ４ 天（每隔 １２ 小时给药一次）对猪链球菌病的治愈率分别是 ５０％ 、８０％ 、８０％ 及 ８０％ ,而链球菌感染对照组的死亡率为 ５０％ 。     

氧氟沙星对实验性鸡大肠杆菌病的药效研究

以试管肉汤两倍稀释法测得氧氟沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度分别为０．１及１．６ｍｇ／Ｌ，按５，１０和２０ｍｇ／ｋｇ的氧氟沙星及４０ｍｇ／ｋｇ的氯霉素分别给实验性鸡大肠杆菌病患鸡内服，每１２ｈ服药１次，共３ｄ。这些药物对鸡大肠杆菌病的治愈率分别为９０．０％，９３．３％，９６．７％及８３．３％，而感染对照鸡的死亡率为６３．３％。氧氟沙星和氯霉素的增重效果极显著高于感染对照鸡（Ｐ＜０．０１）。     

氟罗沙星对鸡败血支原体和大肠杆菌混合感染的疗效

以人工诱发鸡败血霉形体和大肠杆菌混合感染模型,评价氟罗沙星的疗效。按每升水加入２５ｍｇ、５０ｍｇ及１００ｍｇ氟罗沙星及５０ｍｇ环丙沙星的用量给病鸡饮水给药,连续５天,对混合感染鸡的治愈率分别是８６．７％、９０．０％、９０．０％及８３．３％,而感染对照组的死亡率为６３．３％;用药组的相对增重率分别为１０１．３％、１０５．７％、１０７．２％及１０２．４％,均显著高于感染对照组（５８５．５％,Ｐ〈０．０１）     

洛美沙星对实验性鸡葡萄球菌病的药效研究

为了给兽医临床推广应用国内新近研制的氟喹诺酮类长半减期药物洛美沙星（Ｌｏｍｅｆｌｏｘａｃｉｎ），特别是用洛美沙星防治鸡葡萄球菌病提供依据，首先以试管２倍稀释法测定了洛美沙星及对照药对金黄色葡萄球菌的最小抑菌浓度，然后观察了洛美沙星、环丙沙星、恩诺沙星饮水给药５ｄ对实验性鸡葡萄球菌病的疗效。结果，洛美沙星、环丙沙星、恩诺沙星、诺氟沙星、红霉素对鸡金黄色葡萄球菌Ｃ５６０１１株的最小抑菌浓度分别为１．０、０．１２５、０．２５、１．０、３２ｍｇ／Ｌ。２５、５０、１００ｍｇ／Ｌ洛美沙星饮水给药对鸡葡萄球菌病的治愈率分别为６６．７％、８０．０％、７６．７％，有效率分别为９０．０％、９６．７％、９６．７％。５０ｍｇ／Ｌ环丙沙星、５０ｍｇ／Ｌ恩诺沙星的治愈率则分别为７６．７％、８０．０％，有效率分别为９３．３％、９６．７％。５０、１００ｍｇ／Ｌ洛美沙星及５０ｍｇ／Ｌ恩诺沙星３个饮水给药组的增重显著高于感染对照组。结果表明，洛美沙星饮水给药治疗鸡葡萄球菌病以５０ｍｇ／Ｌ的剂量为宜。     

沙拉沙星对实验性感染猪链球菌病及大肠杆菌病的药效学

为兽医临床合理应用沙拉星（Ｓarafloxacin）提供理论依据,就其对实验性感染猪链球菌 病及大肠杆菌病的药效学进行了研究。以试管２倍稀释法测得沙拉沙星对兰氏Ｃ群类马链球菌（Ｃ５５１２０）和猪大肠杆菌（Ｏ５５）的最小抑菌浓度（ＭＩＣ）分别是０．８mg/Ｌ及０．０５mg/Ｌ。肌注给药对猪链球菌病和大肠杆菌病的试验性治疗结果不明,低、中 高剂量沙拉沙星组２．５、５、１０mg/kg）及环丙沙星组（５mg/kg）用药５d（每隔１２     

洛美沙星对实验性鸡葡萄球菌病的药效研究

为了探讨国内新近研制的氟喹诺酮类长半减期药物洛美沙星（Ｌｏｍｅｆｌｏｘａｃｉｎ）对鸡葡萄球菌病的疗效进行了本研究。以试管２倍稀释法测定洛美沙星及对照药对金黄色葡萄球菌的最小抑菌浓度，然后用洛美沙星、环丙沙星、恩诺沙星进行饮水给药５ｄ的疗效试验。结果表明，洛美沙星、环丙沙星、恩诺沙星、诺氟沙星、红霉素对鸡金黄色葡萄球菌Ｃ５６０１１株的最小抑菌浓度分别为１．０、０．１２５、０．２５、１．０、３２ｍｇ／Ｌ。２５、５０、１００ｍｇ／Ｌ洛美沙星饮水给药对鸡葡萄球菌病的治愈率分别为６６．７％、８０％、７６．７％，有效率分别为９０％、９６．７％、９６．７％。５０ｍｇ／Ｌ环丙沙星、恩诺沙星的治愈率则分别为７６．７％、８０％，有效率分别为９３．３％、９６．７％。５０、１００ｍｇ／Ｌ洛美沙星及５０ｍｇ／Ｌ恩诺沙星３个饮水给药组鸡的增重显著高于感染对照组。     

国产伊维菌素口服液对绵羊寄生虫的驱除试验

本文利用中国农业大学生产的伊维菌素（Ｉｖｅｒｍｅｃｔｉｎ）口服液，选择１．５～２．０岁严重感染消化道线虫和某些外寄生虫的绵羊１００只，分别口服０．１５ｍｇ／ｋｇ、０．２５ｍｇ／ｋｇ和０．３０ｍｇ／ｋｇ体重的剂量，同时用进口害获灭（Ｉｖｏｍｅｃ）以０．２ｍｇ／ｋｇ体重皮下注射作对照。结果表明：①０．２５ｍｇ／ｋｇ和０．３０ｍｇ／ｋｇ口服液对消化道线虫的虫卵转阴率、虫卵减少率和驱虫率均为１００％，对羊狂蝇蛆、痒螨病和羊虱能全部杀死；②０．１５ｍｇ／ｋｇ口服液对奥斯特线虫的虫卵减少率仅为９２．３％。对奥斯特线虫、毛圆线虫、毛首线虫的驱除率分别为９８．５％、９９．２％、９３．３％。对其余线虫的驱虫率均为１００％。其驱虫效果略次于０．２５ｍｇ／ｋｇ、０．３０ｍｇ／ｋｇ两剂量组；③对照药物害获灭对奥斯特线虫的虫卵减少率和驱虫率分别为９７．６％和９５．５％，对其余线虫的驱虫率也为１００％。总之，从成本考虑，国产伊维菌素０．１５ｍｇ／ｋｇ口服液口服经济、实惠、高效、安全     

脱氧土霉素对人工诱发鸡大肠杆菌病的疗效观察

以试管两倍稀释法测定脱氧土霉素对鸡大肠杆菌的最小抑菌浓度，然后对人工诱发雏鸡大肠杆菌进行混饮或混料给药５天的治疗试验。结果表明，脱氧土霉素对鸡大肠杆菌的最小抑菌浓度为２．０ｍｇ／Ｌ；脱氧土霉素１００ｐｐｍ混饮和２００ｐｐｍ混饲对鸡大肠杆菌病的治愈率分别是９０．０％及９３．３％，而感染对照组的死亡率为６０．０％；用药组的增重效果显著高于感染对照组（Ｐ＜０．０５）。     

0.6%伊维菌素预混剂驱除野生动物体外寄生虫的试验观察

０．６％伊维菌素预混剂是伊维菌素的一种新制剂。草食动物按０．２ｍｇ／ｋｇ体重、肉食动物０．２５ｍｇ／ｋｇ体重平均连续饲喂分别为７天和２天,对野生动物长角血蜱病、螨病、虱病的治愈率分别达１００％、８７．５０％、８５．７１％,且安全、无毒副作用,值得在野生动物上推广和应用。     

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.     

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