Tests on Methyridine as an Anthelmintic in Sheep

The results of critical tests on methyridine in naturally parasitized sheep are given. The drug proved to be efficient against most species found in the small intestine. It was less effective against those in the large intestine. Against the abomasal worms, Haemonchus and Ostertagia, activity was generally poor. The drug appeared to show activity against lungworm and to reduce larval development in the faeces after dosing.     

Anthelmintic Resistance on an Organized Sheep Farm in India

Monitoring anthelmintic resistance in strongyle nematodes by the faecal egg count reduction test and a commercial larval development assay on an organized sheep farm in the semi-arid area of Rajasthan revealed the emergence of resistance to benzimidazoles and rafoxanide and a potential risk of the development of levamisole/tetramisole resistance. A benzimidazole/levamisole combination, avermectins and closantel were each found to be efficacious.     

Multiple Anthelmintic Resistance in Haemonchus Contortus on a Sheep Farm in Kenya

Multiple resistance to albendazole, thiophanate, levamisole and orally administered ivermectin was detected in an isolate of Haemonchus contortus in sheep on a farm where benzimidazole resistance had already been identified. Following a faecal egg count reduction test, this was confirmed by both critical and controlled anthelmintic tests. Different groups of sheep infected naturally or given an experimental infection with the benzimidazole-resistant isolate were treated with the recommended doses of various anthelmintics. Compared to the control group, the percentage reductions in the faecal egg counts of sheep treated with albendazole, thiophanate, levamisole and ivermectin varied between 38.2% and 79.1% and the residual worm counts between 27.3% and 57.5%. The results indicate the presence of multiple anthelmintic resistance in this isolate of H. contortus. Sheep treated with closantel showed 100% reductions in faecal egg and worm counts, indicating that this drug was very effective against the population of H. contortus on the farm.     

Thiabendazole as an anthelmintic against Hyostrongylus rubidus and Oesophagostomum dentatum in pigs

Extract

These, of course, are the well-known opening lines from the play Under Milk Wood, by the celebrated poet and author Dylan Thomas. These magic words of that illustrious Celt open the prelude of a play for voices that reveals attitudes to living, shades of so-called morality, and sides of human nature unknown to the casual observer: important sides for those who wish to face life in its genuine perspective.     

Evolution of High-level,Multiple Anthelmintic Resistance on a Sheep Farm in Malaysia

Anthelmintic resistance in nematode parasites of sheep and goats on a government farm in north Malaysia was monitored over a 3-year period (1997–2000). The faecal egg count reduction test (FECRT) was conducted on young sheep at the beginning and end of this period. Changes in management, designed to reduce the selection pressure for the development of anthelmintic resistance, were also implemented during this time. By far the most important parasite problem was Haemonchus contortus. In 1997, this nematode was found to be resistant to levamisole, with suspected resistance to closantel and moxidectin. However, when the FECRT was repeated 3 years later, its resistance status had become much more severe, with resistance to benzimidazole, levamisole and ivermectin, and suspected resistance to moxidectin. This rapid evolution to multiple anthelmintic resistance is a major concern that needs to be arrested. There is an urgent need to evaluate other control strategies that incorporate livestock management, the `smart' use of drugs and non-chemotherapeutic approaches, such as biological control agents.     

The efficiency of Thiabendazole (MK 360) as an anthelmintic in sheep

Abstract

Extract

Thiabendazole (MK 360) (Merck) is a new anthelmintic about which there has been no literature published as yet? ?Paper received for publication 29 August, 1961. , but unpublished information supplied by the manufacturers showed it to be a very promising addition to the existing series. It is rapidly absorbed and readily excreted, and therefore does not accumulate in the body. The compound is non-staining and has a wide safety margin. It may be administered in the form of a drench, bolus or capsule.     

两种驱虫药物驱除羊肝片吸虫的效力试验

应用三氯苯咪唑片剂和氯氰碘柳胺钠注射液,选择6~8月龄自然感染肝片吸虫的绵羊80只进行驱虫试验。结果:(1)三氯苯咪唑片剂5、10、15 mg/kg体重剂量对肝片吸虫的虫卵转阴率、减少率和成虫的驱虫率均达100.0%,对肝片吸虫幼虫的驱虫率分别为93.9%、100.0%和100.0%;(2)氯氰碘柳胺钠注射液5、10、15 mg/kg体重剂量对肝片吸虫的虫卵转阴率分别为60.0%、80.0%和100.0%,减少率分别为89.2%、98.2%和100.0%,对成虫驱虫率均分别为97.9%、100.0%和100.0%,幼虫驱虫率分别为90.7%、94.3%和100.0%;(3)三氯苯咪唑片剂10 mg/kg体重剂量与同剂量对照药物三氯苯咪唑混悬剂的驱虫效果无差异;(4)三氯苯咪唑片剂和氯氰碘柳胺钠注射液3个剂量组试验羊未见异常反应。试验证明,三氯苯咪唑片剂5、10、15 mg/kg体重和氯氰碘柳胺钠注射液10、15 mg/kg体重剂量驱除绵羊肝片吸虫安全高效。驱除绵羊肝片吸虫两种药物的使用剂量,三氯苯咪唑片剂不低于5 mg/kg,氯氰碘柳胺钠注射液不低于10 mg/kg体重。     

多拉菌素等三种药物驱除绵羊胃肠道线虫效果观察

通过选取多拉菌素等三种驱虫药物对绵羊胃肠道线虫进行驱除。结果表明,三种药物对绵羊胃肠道线虫均有明显效果,平均驱虫率依次为多拉菌素组（98.7%）〉伊维菌素组（94.3%）〉丙硫苯咪唑组（82%）。比较后确定适合我市推广的新型驱虫药物为多拉菌素注射液。     

高效液相色谱法检测羊鸡组织中氟苯达唑、噻苯达唑及其代谢物残留量的研究

建立了一种可同时检测羊组织（肌肉、肝脏、肾脏、脂肪）、鸡组织（肌肉、肝脏）中氟苯达唑及代谢物2-氨基氟苯达唑、噻苯达唑及代谢物5-羟基噻苯达唑药物残留的高效液相色谱检测方法。结果表明：氟苯达唑及代谢物2-氨基氟苯达唑、噻苯达唑及代谢物5-羟基噻苯达唑在0.02～1.5μg/mL浓度范围内呈良好的线性关系r,均大于0.999。方法的定量限为20μg/kg。在鸡组织（肌肉、肝脏）中,两种药物及其代谢物在20～800μg/kg的添加浓度范围内,其回收率范围在60%～100%之间;在羊组织（肌肉、肝脏、肾脏、脂肪）中,两种药物及其代谢物在20～200μg/kg的添加浓度范围内,其回收率范围在60%～100%之间;批内变异系数均小于15%、批间变异系数均小于20%。     

The Effect of Strategic Anthelmintic Treatment on Internal Parasites in Communally Grazed Sheep in a Semi-Arid Area as Reflected in the Faecal Nematode Egg Count

Communally grazed sheep were dosed at 4-, 12-, 24- or 48-week intervals for 1 year. Dosing every 4 weeks proved to be the most effective (p<0.05), as reflected in a lower worm egg count compared to the 12-, 24- or 48-week intervals. Since most nematode life cycles lie between 3 and 6 weeks, the treatment has to be given during this critical period if maximum economic advantage is to be gained from deworming. However, treating communally grazed sheep every 12 weeks was found to keep worm egg numbers relatively low and may be advantageous in providing seasonal control, especially in semi-arid environments. Dosing communally grazed sheep once or twice a year under the same conditions is not recommended because reinfection appeared to result in similar faecal egg counts to those from the untreated animals (p>0.05).     

Sheep as an experimental model ofTaenia saginata cysticercosis

Summary Taenia saginata cysticercosis was experimentally produced in 4 Soay sheep, 1 four-horned sheep and 1 Texel sheep by oral administration of eggs of the parasite. Some of these sheep were given dexamethasone therapy. The evolution ofT. saginata cysticercosis in this host is characterised by a rapid immune reaction so that by 6 weeks after infection almost all the cysts were dead. There were indications that the dexamethasone therapy may have assisted establishment of the infection and to some extent, postponed the process of degeneration.

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Ovejas Como Modelo Experimental De Cisticercosis PorTaenia Saginata

Resumen Se produjo cisticercosis experimental mediante la administración oral de huevos deTaenia saginata a 4 ovejas Soay, 1 oveja cuatro cuernos y 1 oveja Texel. Algunas ovejas recibieron terapia con dexametasona. La evolución de la cisticercosis en estos huéspe des se caracteriza por una reacción inmunitaria rápida, con muerte de los quistes a la sexta semana después de la infección. Hubo indicaciones de que la dexametasona ayudó en el establecimiento de la infección, posponiendo el proceso degenerativo de los quistes.

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Le Mouton Comme Modele Experimental De Cysticerques DeTaenia Saginata

Résumé Des cysticerques deTaenia saginata ont été expérimentalement obtenus chez 4 moutons Soay, un mouton à quatres cornes et un mouton Texel à la suite de l'administration d'oeufs de ce parasite. Certains de ces moutons ont fait l'objet d'un traitement à la dexamethasone. L'évolution de cysticerques deT. saginata chez l'hôte est caractèrisée par une réaction immunitaire rapide qui fait que 6 semaines après l'infection la presque totalité des cysticerques sont morts. Il existe des indications montrant que le traitement à la dexamethasone peut avoir contribué à l'établissement de l'infestation et à un retard dans le processus de dégénerescence.

     

A Preliminary Study on the Anthelmintic Activity of Calotropis procera Latex against Haemonchus contortus Infection in Najdi Sheep

The anthelmintic activity of Calotropis procera latex was investigated in sheep that had been infected with single oral doses of 12 000 infective Haemonchus contortus larvae. Inappetence, dullness, erosive abomasitis, decreased haemoglobin concentration and increased eosinophils were the main features of haemonchosis in the sheep. In the sheep treated with single oral doses of 0.01 ml or 0.02 ml/kg body weight of C. procera latex, egg production was significantly reduced, but not completely suppressed, and fewer adult Haemonchus worms were found in the abomasum. Although the appetite improved, the haemoglobin concentration and serum copper, iron and zinc levels were still reduced after therapy with Calotropis latex. Calotropis latex showed a concentration-dependent larvicidal activity in vitro within 20 min of application.     

绵羊卵泡发育过程中关键信号通路研究进展

卵泡从原始卵泡发育为成熟卵泡,直至排卵、黄体发育等过程都受到精密的调控,产生大量的优势卵泡是绵羊产多羔及实现快速扩繁的关键因素。研究发现,相关信号通路和转录因子通过影响绵羊卵泡中卵母细胞、颗粒细胞的生长,进而调控卵泡的发育成熟,对这些信号通路进行深入了解,有助于探索卵泡发育的调控机制,早日实现绵羊高效繁育。Notch是卵泡发育过程中发挥重要作用的高度保守信号通路,PI3K/AKT/mTOR信号通路各成员都是广泛存在于细胞内的信号转导分子,在卵泡发育早期发挥了主要作用,还有间隙连接（gap junction,GJ）和跨带突触（transzonal projections,TZPs）等物理连接方式,在细胞间的交流通讯起到重要作用。作者详细介绍了Notch信号通路、PI3K/AKT/mTOR信号通路、间隙连接及跨带突触的结构功能在绵羊卵泡发育中的调控作用,为进一步探明绵羊卵泡发育的调控机制提供参考。