芬苯达唑驱除藏系绵羊肝片吸虫效果试验

分别以10 mg/kg、15 mg/kg、20 mg/kg三种剂量的芬苯达唑给藏系绵羊驱除自然感染的肝片吸虫,投药1周后,虫卵转阴率分别为20%、40%、40%,减卵率分别为93.42%、90.08%、95.70%.     

芬苯达唑干混悬剂对绵羊裸头科绦虫的驱除效力试验

应用芬苯达唑干混悬剂,分别按5,10,20mg/kg体重剂量驱除绵羊裸头科绦虫,并设吡喹酮片剂20mg/kg体重剂量药物对照组和阳性对照组。粪检结果:芬苯达唑干混悬剂5,10,20mg/kg剂量对裸头科绦虫的粪便虫卵(节片)转阴率分别为70.0%、100.0%和100.0%。用药后14d剖检结果:芬苯达唑干混悬剂5mg/kg体重剂量对莫尼茨绦虫、无卵黄腺绦虫的驱虫率分别为70.7%、63.0%;10、20mg/kg体重剂量的驱虫率均达100.0%。结果表明10mg/kg和20mg/kg体重芬苯达唑干混悬剂试验剂量对绵羊裸头科2属绦虫均有效,其中10mg/kg以上剂量驱除绵羊裸头科绦虫高效安全。     

盐酸左旋咪唑驱除绵羊肠道线虫试验

用10％盐酸左旋咪唑注射液8mg/kg体重、12mg/kg体重剂量臀部肌肉注射，驱除绵羊肠道线虫安全有效，且药源广，价格低廉，给药途径方便。按每kg体重12mg剂量臀部肌肉注射，7天后检查绵羊肠道线虫基本消灭，治疗效果100％，可作为推荐剂量在农牧区使用。     

舍饲绒山羊体外寄生虫药物防治效果观察

选择不同程度感染山羊疥螨与山羊鄂虱的舍饲绒山羊360只作为试验及对照羊,应用15% 林丹乳油500倍稀释及40%赛福丁1000倍稀释分别进行药浴;20%碘硝酚10mg/kg及1%阿克丁0.2mg/kg皮下注射。结果表明,4种药物均有良好的防治效果。根据本地区生产的实际,笔者认为,在生产中应选择阿维菌素和伊维菌素类药物在每年的10月末到11月末羊只进入暖舍时进行防治,同时注意羊舍的通风,保持干燥,定期消毒。     

两种药物驱除放牧绵羊线虫的效果对比试验

<正>选用伊维菌素注射剂按0.1、0.2、0.3mg/kg剂量和盐酸左旋咪唑片剂7.5、15、22.5mg/kg剂量对放牧绵羊进行驱虫试验,分别于给药后7d、14d检查效果。结果:伊维菌     

伊维菌素微乳剂在绵羊体内的药代动力学研究

研究伊维菌素微乳剂在绵羊体内的药代动力学,对比高含量伊维菌素微乳剂与普通注射剂型的生物利用度差异。选取12只绵羊,分为2组,按照0.2 mg/kg体重分别皮下注射10 mg/mL伊维菌素注射液和30 mg/mL伊维菌素微乳剂。分别在给药前0.5 h,给药后2、4、6、8、10、12、16、20、24、36、48、96、144、192、240、336 h在颈静脉采集血液备用,用高效液相色谱荧光检测器对绵羊血浆中的伊维菌素进行检测,并利用内标法计算其含量。通过DAS2.1.1软件进行数据统计分析。结果显示,伊维菌素微乳剂组药时曲线下面积(AUC)为3 812.17 ng/mL·h,达峰浓度(C_(max))为97.71 ng/mL,达峰时间(T_(max))为12 h,消除半衰期(T_(1/2z))为43.46 h;伊维菌素注射液组AUC为2 501.25 ng/mL·h,C_(max)为48.15 ng/mL,T_(max)为24 h,T_(1/2z)为44.96 h。说明伊维菌素微乳剂吸收效果好,达峰时间短,达峰浓度高,生物利用度高。     

丙硫苯咪唑驱除绵羊体内寄生虫的增重试验

目的观察丙硫苯咪唑对绵羊体内寄生虫的驱除效果,以及驱除体内寄生虫对绵羊的增重作用。方法选择自然放牧的青年绵羊80只,分为对照组和试验组,给药后分期检查虫卵和称重,最后进行统计分析。结果按20 mg/kg.BW剂量投服药物残效期大约能维持30 d左右。试验结束后试验组比对照组每只绵羊平均多增重4.1 kg。结论丙硫苯咪唑的驱虫作用广谱、安全,对绵羊体内多种寄生虫的驱除效果确实。体内驱虫对绵羊增重作用明显,经济效益可观。     

伊维菌素注射剂对绵羊体外寄生虫病的防治示范

应用伊维菌素注射剂进行自然感染绵羊主要体外寄生虫病的防治示范,选择其中1.5~2岁感染体外寄生虫较严重的绵羊48只,分别按0.1;0.2;0.3mg/kg剂量皮下注射给药,进行防治效果评价,并设阳性对照组。结果:伊维菌素注射剂0.2,0.3mg/kg剂量对绵羊颚虱、足颚虱的转阴率和杀虫率均达100.0%;对羊蜱蝇的转阴率分别为91.7%和100.0%,杀虫率分别为93.8%和100.0%;0.1mg/kg剂量对绵羊颚虱、羊蜱蝇和足颚虱的杀虫率较低;全部试验绵羊给药后未见异常反应。试验证明伊维菌素注射剂驱杀绵羊主要体外寄生虫高效、安全、经济。     

国产咪唑苯脲对梨形虫病和无定形体病的疗效评价

应用国产咪唑苯脲,按2mg/kg剂量肌肉注射治疗20例驽巴贝西虫病马,14例间隔24h用药2次,6例仅用药1次,均获治愈。按1～4.5mg/kg剂量一次肌肉注射治疗45例双芽巴贝西虫病黄牛,29例早、中期病例全部治愈,16例晚期病例,治愈14例,治愈率87.5％。按1.5mg/kg剂量一次肌肉注射治疗4例双芽巴贝西虫病黄牛,全部治愈。以1mg/kg,1.5mg/kg、2mg/kg剂量一次肌肉注射治疗46例水牛巴贝西虫病牛,1mg/kg剂量治疗12例,治愈9例,治愈率75％;1.5mg/kg剂量组24例及2mg/kg剂量组10例全部治愈。应用1.5mg/kg剂量间隔24h 2次肌肉注射治疗18例羊泰勒虫病羊,治愈16例,治愈率88.9％。以1～4.5mg/kg剂量1～8次肌肉注射治疗22例无定形体病牛,17例早、中期病例全部治愈,5例晚期病例全部死亡,治愈率77.3％。咪唑苯脲安全性较好,对牛、马加大剂量至8mg/kg,水牛6mg/kg,仅出现一过性的呼吸困难、流涎、肌肉颤抖、腹痛和排稀粪等副反应,约经30min后消失。     

绵羊的铜中毒症

铜中毒症与钼缺乏症的差异很难区分,通过观察并请兽医进行诊断,有可能降低铜中毒症对家畜的危害。Parkham等(1978)指出,要区分反刍家畜的钼缺乏症与铜中毒症是不可能的,例如,绵羊在放牧条件下,当土壤和牧草中铜的含量正常但钼的含量极低(0.1～0.2mg/kg)时会出现铜中毒症;当牧草中钼含量在0.35mg/kg以下时,促进铜在绵羊组织内的积累造成慢性铜中毒;当牧草中钼含量很低(1mg/kg)而铜含量正常(8～11mg/kg)时,也会出现铜中毒症。McDowell(1992)指出,当饲料干物质中钼含量低于1mg/kg时,铜的理想含量为6～8mg/kg,而当钼含量为1～3mg/kg时,8mg/kg…     

甘草提取物对绵羊皮下脂肪沉积与代谢相关酶活性的影响

作者旨在探讨添加不同水平甘草提取物(LE)对绵羊皮下脂肪沉积及代谢相关酶活性的影响。采用单因素试验设计,选用健康、断奶后20~30 d、初始体重相近的宁夏滩羊公羔50只,随机分为5组,每组10只,其中对照组饲喂基础日粮,不添加LE;试验Ⅰ~Ⅳ组分别在基础日粮中添加1000、2000、3000、4000 mg/kg LE。试验期120 d,试验结束后进行屠宰并测定滩羊皮下脂肪重、血清脂质代谢相关指标及皮下脂肪代谢相关酶活性。结果表明,与对照组相比,试验Ⅰ~Ⅳ组的皮下脂肪重分别降低了20.16%、14.40%、18.11%、20.16%;添加3000 mg/kg LE降低血清总胆固醇的效果最明显,LE对总甘油三酯(TG)和高密度脂蛋白(HDL-C)含量均无显著影响(P>0.05);LE显著降低皮下脂肪组织葡萄糖-6-磷酸脱氢酶(G6PDH)活性(P<0.05),其中添加3000 mg/kg LE降低G6PDH活性的效果最佳,对脂肪酸合成酶(FAS)、苹果酸脱氢酶(MDH)、异柠檬酸脱氢酶(ICDH)和6-磷酸脱氢酶(6PGDH)活性的影响均未达到显著水平(P>0.05)。提示,LE有降低血清总胆固醇和皮下脂肪重的趋势,其中添加3000 mg/kg LE的降脂作用最好,甘草提取物主要通过下调脂肪合成途径的关键酶活性来抑制绵羊皮下脂肪沉积,但甘草提取物调控滩羊皮下脂肪代谢关键酶的机制,尚需进一步研究。     

The effect of shade, shearing and wool type in the protection of Merino sheep from Hypericum perforatum (St John's wort) poisoning

OBJECTIVE: To investigate the roles of shade, fleece length and wool type in the protection of sheep from Hypericum perforatum poisoning. ANIMALS: Adult Merino ewes of superfine, fine and medium wool type. DESIGN: Seventy sheep were divided into seven equal groups. During late spring and summer a series of successive, replicate experiments was conducted, each using one group and lasting 5 days. The sheep carried 14 to 24 weeks wool growth. In each experiment the treatments tested were Hypericum +, sunlight + (n = 7); Hypericum +, sun - (n = 1); Hypericum -, sun + (n = 1); Hypericum -, sun - (n = 1). Next, 24 sheep in two equal groups were used in experiments of similar design to the above. Each group consisted of nine recently (1 to 3 weeks previously) shorn and three wool covered (25 to 26 weeks growth) sheep. The treatments tested were Hypericum +, sunlight +, fleece - (n = 9); Hypericum +, sun -, fleece + (n = 1); Hypericum -, sun +, fleece + (n = 1); Hypericum -, sun -, fleece + (n = 1). PROCEDURES: Finely milled Hypericum was administered by gavage to provide 3 mg hypericin / kg body weight. Sheep were sheltered from direct sunlight or were exposed for 5 h per day for 4 successive post-treatment days. Rectal temperatures were measured immediately before and at the end of each sunlight exposure session. Rectal temperature above 40 degrees C was considered indicative of hypericin poisoning. RESULTS: After Hypericum treatment hypericin poisoning was displayed by 26.5% of woolled sheep that were exposed to sunlight, but by none of those that were fully shaded. In similarly treated but recently shorn sheep 94% displayed hypericin poisoning when exposed to sunlight. In the wool covered group the percentages of poisoned animals based on wool type were: superfine 14%, fine 28.5%, medium 33.3%. In the recently shorn group the percentage for all three approached 100%. CONCLUSIONS: A majority of Merinos with at least 14 weeks wool growth will not be poisoned by a single oral dose of 3 mg hypericin /kg, but because hypericin persists in the blood circulation for several days this safe dose will be lowered by continuous daily ingestion. Sheep with access to substantial areas of shade could safely ingest much greater amounts of hypericin. Wool removal greatly increases the risk of poisoning. Superfine Merinos with a wool cover should be able to ingest more hypericin than comparable, medium wool types, without any increased risk of poisoning. The ability of ruminant livestock to safely ingest Hypericum is probably determined more by the amount of skin protection they have against incident sunlight than by differences in hypericin metabolism and excretion capacity.     

Experimental evidence that tryptamine alkaloids do not cause Phalaris aquatica sudden death syndrome in sheep

The acute toxicity for sheep of 3 alkaloids that occur in Phalaris acquatica was examined by intravenous and oral administration. The lowest tested dose rates that produced clinically observed signs were, for 5-methoxy dimethyltryptamine, 0.1 mg/kg body weight intravenously and 40 mg/kg orally; for gramine, 10 mg/kg intravenously and 500 mg/kg orally; and for hordenine, 20 mg/kg intravenously and 800 mg/kg orally. All induced the clinical signs observed in the nervous form of phalaris toxicity, but none induced the cardiac, sudden death, syndrome.     

Evaluation of the effect of two dose rates of cyclosporine on the severity of perianal fistulae lesions and associated clinical signs in dogs

OBJECTIVE: To investigate the effect of cyclosporine (2 or 5 mg/kg every 24 hours) on perianal fistulae (PAF) lesions. STUDY DESIGN: Blinded randomized, prospective trial. ANIMALS: Dogs (n = 20) with perianal fistulae. METHODS: Dogs were randomly assigned to administration of either 2 mg/kg (n = 10) or 5 mg/kg (n=10) of cyclosporine orally every 24 hours for 8 weeks. Lesion surface area was measured, lesion severity was graded using a visual analog scale, and the presence and severity of clinical signs recorded every 2 weeks. RESULTS: Lesion variables were significantly reduced in both groups after 8 weeks and owners also reported a reduction in clinical sign severity. The 5 mg/kg dose rate significantly accelerated lesion resolution compared with 2 mg/kg. In the 2 mg/kg group, 20% of dogs had complete resolution of clinical signs and 10% had resolution of lesions. In the 5 mg/kg group, 40% of dogs had complete resolution of clinical signs and 60% had resolution of lesions. CONCLUSIONS: A dose rate of 5 mg/kg every 24 hours was more effective at reducing the surface area and severity of PAF lesions than 2 mg/kg every 24 hours but less effective at resolving PAF lesions than previous studies using dose rates > or =5 mg/kg every 12 hours. CLINICAL RELEVANCE: Cyclosporine at 5 mg/kg every 24 hours may be useful for the palliation of PAF lesions.     

Enhanced Plasma Availability of the Metabolites of Albendazole in Fasted Adult Sheep

Lifschitz, A., Virkel G., Mastromarino, M. and Lanusse C., 1997. Enhanced plasma availability of the metabolites of albendazole in fasted adult sheep. Veterinary Research Communications, 21 (3), 201-211The influence of fasting prior to treatment and of dosing rate on the plasma availability and disposition kinetics of albendazole (ABZ) and its sulphoxide (ABZSO) and sulphone (ABZSO2) metabolites was studied in adult sheep grazing on pasture. A micronized suspension of ABZ was administered orally at either 7.5 mg/kg (group A) or 11.3 mg/kg (group C) to sheep fed ad libitum, and at 7.5 mg/kg to sheep subjected to a 24 h fasting period prior to treatment (group B). Blood samples were taken serially over 96 h after treatment, and the plasma was analysed for ABZ and its metabolites by high-performance liquid chromatography. ABZSO and ABZSO2 were recovered from the plasma. Fasting induced marked modifications in the pharmacokinetic behaviour of the ABZ metabolites in sheep. An extended absorption process, with a delayed peak concentration in the plasma, was observed for both metabolites in the fasted sheep. Significantly higher area under the curve (AUC) and peak plasma concentration (Cmax) values were obtained for both metabolites in the fasted animals compared to those fed ad libitum. Delayed elimination with prolonged detection in plasma was also observed in the fasted sheep. Treatment with ABZ at 7.5 mg/kg in the starved animals resulted in bioequivalence to the administration of the compound at a 50% higher dose rate (11.3 mg/kg) in the fed animals. It is suggested that fasting enhances ABZ dissolution and absorption by delaying its passage down the digestive tract.     

Superphosphate poisoning of sheep: the role of fluoride

Earlier work confirmed that the fundamental lesion of superphosphate poisoning is an acute toxic tubular nephritis in which both phosphate and fluoride may play a part but their respective roles could not be determined. In this study, sheep poisoned by sodium fluoride (NaF) were compared with sheep poisoned by superphosphate containing approximately 1.5% fluoride. The LD₅₀ of NaF was in the range 100 to 300 mg/kg (45 to 135 mg F/kg). This range is of the same order as the amount of fluoride in a toxic dose of superphosphate (70 to 90mg F/kg).

A lethal dose of NaF caused severe depression, salivation, hyperpnoea, blindness, ataxia and incoordination. Death ensued three to 52 hours after dosing. Acute necrotizing rumino-reticulitis and abomasitis and necrosis of epithelial cells in the proximal convoluted tubules of the kidney were the characteristic lesions of NaF toxicity.

Superphosphate poisoning took a more protracted course with depression and diarrhoea as the predominant clinical signs until the terminal coma. As with NaF, the notable lesions were in the gastrointestinal tract and kidneys, but were less severe.

Although there were differences in the clinical and pathological manifestations of the two forms of poisoning, the comparable toxic dose of NaF and of the fluoride in a toxic dose of superphosphate, and the similar target organs involved, support the view that fluoride plays a dominant role in the pathogenesis of superphosphate poisoning. It is probable that phosphate plays a contributory role but the nature of the interaction of fluoride and phosphate remains to be established.     

Superphosphate poisoning of sheep: the role of fluoride

Earlier work confirmed that the fundamental lesion of superphosphate poisoning is an acute toxic tubular nephritis in which both phosphate and fluoride may play a part but their respective roles could not be determined. In this study, sheep poisoned by sodium fluoride (NaF) were compared with sheep poisoned by superphosphate containing approximately 1.5% fluoride. The LD50 of NaF was in the range 100 to 300 mg/kg (45 to 135 mg F/kg). This range is of the same order as the amount of fluoride in a toxic dose of superphosphate (70 to 90 mg F/kg). A lethal dose of NaF caused severe depression, salivation, hyperpnoea, blindness, ataxia and incoordination. Death ensued three to 52 hours after dosing. Acute necrotizing rumino-reticulitis and abomasitis and necrosis of epithelial cells in the proximal convoluted tubules of the kidney were the characteristic lesions of NaF toxicity. Superphosphate poisoning took a more protracted course with depression and diarrhoea as the predominant clinical signs until the terminal coma. As with NaF, the notable lesions were in the gastrointestinal tract and kidneys, but were less severe. Although there were differences in the clinical and pathological manifestations of the two forms of poisoning, the comparable toxic dose of NaF and of the fluoride in a toxic dose of superphosphate, and the similar target organs involved, support the view that fluoride plays a dominant role in the pathogenesis of superphosphate poisoning. It is probable that phosphate plays a contributory role but the nature of the interaction of fluoride and phosphate remains to be established.     

Experiences With Morphine Injected Into the Subarachnoid Space in Sheep

The effects of morphine (M), 0.1 mg/kg, administered into the lumbosacral subarachnoid space of sheep used for experimental stifle surgery, were investigated. In a pilot study, preservative-free morphine was administered to three sheep, morphine containing preservatives to two sheep, and saline (S) to one sheep. After recovery from anesthesia, all five sheep administered M displayed rear limb weakness. One sheep, which had received morphine containing preservatives, also licked and chewed incessantly at its flank and hindquarters during recovery. A group of 24 sheep was used to study the effects of morphine containing preservatives, injected intrathecally, on recovery from general anesthesia and hindlimb orthopedic surgery. Eight sheep received M, eight sheep received S, and eight sheep had a needle placed in the subarachnoid space without any injection (N). Times from end of anesthesia to standing varied greatly and did not differ significantly among groups (P=.73), with M sheep averaging 119 minutes; S sheep, 87 minutes; and N sheep, 83 minutes. One sheep administered M licked and chewed at its hindquarters during recovery. Another group of 24 sheep was used to study the effects of morphine containing preservatives, injected intrathecally, on postoperative lameness. Treatments were as described previously. Sheep were videotaped intermittently for 36 hours after surgery, and each sheep was scored as follows; 0 = not lame; 1 = slightly lame; and 2 = very lame. The average lameness scores, which did not differ significantly among groups (P=.21), were: M sheep, 1.07; S sheep, 0.81; and N sheep, 0.68. One sheep administered M displayed extensor spasms of the hindlimbs, and could not stand until several hours after surgery. We conclude that subarachnoid morphine at the dosage used produces no apparent benefit in sheep which have had stifle surgery, and in fact may cause detrimental side effects, such as hindlimb weakness, and pruritis or irritation of the hindquarters.     

Emory milkvetch (Astragalus emoryanus var emoryanus) poisoning in chicks, sheep, and cattle.

A severe outbreak of Emory milkvetch poisoning in cattle and sheep occurred near Roswell, New Mexico, in the spring of 1975. Mortality averaged 2% to 3% and morbidity averaged 15% to 20%. Emory milkvetch collected from the infested area contained miserotoxin measured as 5 to 9 mg of NO2/g of plant (dry weight). Chicks fed extracts of Emory milkvetch showed toxic signs when fed one dose as 300 mg of NO2/kg of body weight, and died within 5 to 8 hours when fed milkvetch as 400 mg of NO2/kg. A sheep fed Emory milkvetch for 7 days in the form of 38 mg of NO2/kg/day developed signs of nitro poisoning on the 7th day. Cattle were poisoned or died when fed Emory milkvetch as 12 to 20 mg of NO2/ig for several days. The toxic signs observed in the field and under experimental conditions were similar.     

Estimation of Glomerular Filtration Rate in Normal Sheep by the Disappearance of Iohexol from Serum

Nesje, M., Flåøsyen, A. and Moe, L., 1997. Estimation of glomerular filtration rate in normal sheep by the disappearance of iohexol from serum. Veterinary Research Communications, 21 (1), 29-35. The aim of the study was to establish reference values for glomerular filtration rate (GFR) in healthy sheep from the clearance of iohexol in serum. Fifteen healthy sheep were tested twice with 14 to 21 days between tests. No side-effects were observed after iohexol injections and all the sheep were clinically normal during and after the study. The mean clearance of iohexol estimated by the two-compartment method was 1.8 ml/min per kg (95% CI = 1.6-2.0) in the first trial and 1.7 ml/min per kg (1.5-1.9) in the second trial. The mean GFRiohexol estimated by a one-compartment method was 1.9 ml/min per kg (1.7-2.2) in the first trial and 1.8 ml/min per kg (1.6-2.0) in the second. The GFR values were similar to those reported for the inulin method. The results indicate that the iohexol method is valid for estimating GFR in sheep, and it is easier to perform than the inulin method.