不同药物对放牧山羊捻转血矛线虫驱虫效果比较试验

为了筛选山羊捻转血矛线虫的理想驱虫药物,对8组检出有捻转血矛线虫感染的山羊群分别采用不同剂量的阿苯达唑、盐酸左旋咪唑、伊维菌素以及阿苯达唑-伊维菌素预混剂进行驱虫效果对比试验。结果盐酸左旋咪唑、伊维菌素以及阿苯达唑-伊维菌素预混剂对山羊捻转血矛线虫驱虫后,虫卵减少率均达95%以上,而阿苯达唑驱虫后的虫卵减少率低于95%。表明左旋咪唑、伊维菌素以及阿苯达唑-伊维菌素预混剂对山羊捻转血矛线虫的驱虫效果较好,而阿苯达唑有一定的抗药性。     

两种药物对高原型牦牛多头蚴病的治疗效果观察

[目的]观察吡喹酮片剂、阿苯达唑干混悬剂对高原型牦牛多头蚴病的治疗效果,确定最佳剂量和用药次数。[方法]应用吡喹酮片剂按35、70 mg/kg剂量口服、阿苯达唑干混悬剂按25、50 mg/kg剂量口服治疗牦牛多头蚴病。[结果]吡喹酮片剂两个剂量的治愈率分别为72.73%和91.67%;阿苯达唑干混悬剂两个剂量的治愈率分别为81.82%和83.33%。从吡喹酮片剂35 mg/kg的剂量组死亡的2头牛检出多头蚴8个,平均感染强度2.67个;从阿苯达唑干混悬剂25 mg/kg的剂量组死亡的1头牛检出脑多头蚴2.0个,平均感染强度2个。从阳性对照组死亡的10头牛检出脑多头蚴37个,平均感染强度3.7个。[结论]吡喹酮片剂70mg/kg剂量间隔5 d三次给药达高效,适于推广应用。     

奥芬达唑和阿苯达唑对猪囊尾蚴作用形态学比较观察

观察了奥芬达唑和阿苯达唑对猪体内及体外培养的不同发育阶段囊尾蚴作用的形态学效果.结果表明奥芬达唑具有显著的疗效,优于阿苯达唑,且对未成熟期猪囊尾蚴的杀灭作用优于成熟期.提示奥芬达唑可能成为抗未成熟期猪囊尾蚴及治疗脑囊虫病的有效药物.     

阿苯达唑对波尔山羊消化道线虫的药效试验

为了观察阿苯达唑片对波尔山羊消化道线虫的驱除效果,探讨其对波尔山羊线虫病治疗的最佳剂量,将150只波尔山羊随机分成5组,其中设阿苯达唑7.5、15、30 mg/kg作为试验组,同时设左旋咪唑7.5 mg/kg作为药物对照组和阳性对照组,给药前后检查虫卵和虫体,计算虫卵转阴率、虫卵减少率和驱虫率,最后进行统计分析。结果显示,高剂量组和中剂量组的虫卵转阴率、虫卵减少率和驱虫率均显著高于低剂量组和盐酸左旋咪唑片对照组(P0.01),而高剂量组与中剂量组的虫卵转阴率、虫卵减少率和驱虫率差异不显著。15 mg/kg的阿苯达唑片对波尔山羊线虫的驱除效果安全。     

阜康市羊消化道线虫驱虫药物筛选

目的:通过试验为阜康市筛选出科学合理的、针对性强的、安全高效的驱虫药物。方法:采用随机对照实验比较阿苯达唑+虫克星与单用阿苯达唑驱虫效果。结果:阿苯达唑+虫克星与单用阿苯达唑驱虫效果之间差异具有统计学意义。结论:"一次驱虫,两次投药"的驱虫方案联合阿苯达唑+虫克星驱虫效果明显优于单用阿苯达唑驱虫效果,从而为阜康市制定合理有效的羊驱虫方案提供可靠的科学依据,以达到提高羊生产性能和经济效益的目的。     

不同用药方法对牦牛多头蚴病的疗效试验

[目的]观察三种不同用药方法对高原型牦牛多头蚴病的治疗效果。[方法]采用吡喹酮增量法、阿苯达唑增量法、吡喹酮和阿苯达唑联合法治疗牦牛多头蚴病。[结果]吡喹酮增量法试验组,症状消失的平均时间为8.25 d;有效率为80.9%,治愈率为72.7%;阿苯达唑增量法试验组,症状消失的平均时间为10.6 d,有效率为100%,治愈率为90.9%;吡喹酮与阿苯达唑联合法组,症状消失的平均时间为12.43 d,有效率为80%,治愈率为60%。[结论]吡喹酮增量法疗效较其它组快;阿苯达唑增量法效果缓慢,但疗效较高;联合用药法疗效欠佳。     

四种药物对兔蛲虫病治疗效果的影响

兔蛲虫病可引起病兔食欲下降,生长缓慢,全身消瘦,严重时会导致病兔死亡,直接造成经济损失。为了解药物对兔蛲虫病治疗效果的影响,本研究应用阿苯达唑伊维菌素粉、盐酸左旋咪唑、盐酸氯苯胍预混剂和芬苯达唑4种药物分别对20只兔进行了药物治疗对比试验,同时设置对照组,通过粪便样品寄生虫检测法,采用卡方检验。结果表明:4种药物组间比较差异显著(P0.05),阿苯达唑伊维菌素粉、盐酸左旋咪唑和芬苯达唑驱虫效果明显高于生理盐水(P0.05)。结论:阿苯达唑伊维菌素粉对兔蛲虫病治疗效果最好,是值得推广的兔蛲虫治疗药物,可作为兔蛲虫病的首选药。     

联合应用阿苯达唑和伊维菌素在线虫感染鄂尔多斯细毛羊体内的药动学研究

为阐明联合应用阿苯达唑(ABZ)和伊维菌素(IVM)在胃肠道线虫感染鄂尔多斯细毛羊体内的药动学互作关系,以感染胃肠道线虫的鄂尔多斯细毛羊为研究对象,比较研究了单独或联合应用阿苯达唑和伊维菌素后的药物动力学特征。通过粪便虫卵检查法,选取感染胃肠道线虫的鄂尔多斯细毛羊15只,随机分成3组,每组5只。第1组口服给予阿苯达唑(15mg/kg),第2组皮下注射伊维菌素(0.2mg/kg),第3组皮下注射伊维菌素(0.2mg/kg)的同时口服阿苯达唑(15mg/kg)。于给药后不同时间,由颈静脉采集血样,分离血浆,并用高效液相色谱法测定各时间点血浆阿苯达唑、阿苯达唑亚砜、阿苯达唑砜和伊维菌素浓度,并用PK Solution 2.0药物动力学软件计算出各药动学参数。结果表明,联合用药组绵羊血浆伊维菌素峰浓度(Cmax)、药时曲线下面积(AUC)和平均滞留时间(MRT)分别为44.80ng/mL±6.12ng/mL、5 007.46ng.h/mL±1 301.42ng.h/mL和85.47h±5.03h,均显著(P<0.05)小于单独用药组的对应参数值67.62ng/mL±9.06ng/mL、7 125.08ng.h/mL±908.52ng.h/mL和113.39h±9.00h。口服阿苯达唑组绵羊血浆中仅检测到了阿苯达唑砜和阿苯达唑亚砜,而未检测到阿苯达唑母药。联合用药后,除阿苯达唑砜的达峰时间(T max)显著推迟外,阿苯达唑砜和阿苯达唑亚砜的其他各参数之间均无显著性差异。因此,联合应用IVM和ABZ可影响它们在胃肠道线虫感染鄂尔多斯细毛羊体内的药动学特征,且对伊维菌素药动学特征的影响尤为明显,在临床联合用药过程中应予以重视。     

阿苯达唑及其脂质体治疗羊肝包虫病的病理学比较观察

肝包虫病(hydatid disease)又称肝细粒棘球蚴病(echinococcosis),是棘球蚴的童虫寄生于人体及某些动物体内所致的严重的人畜共患病.阿苯达唑是WHO指定治疗肝包虫病的首选药物,但其吸收差,而阿苯达唑脂质体被认为具有较好的吸收率.为了进一步了解两种药物在绵羊包虫病治疗方面的疗效,研究设计了阿苯达唑、阿苯达唑脂质体治疗绵羊包虫病的对比试验,以期为肝包虫病的治疗提供有力的依据.     

阿苯达唑干混悬剂驱除绵羊线虫的效力与安全性试验

应用阿苯达唑干混悬剂按10mg/kg、15mg/kg、20mg/kg剂量驱除绵羊线虫,并设药物对照组和空白对照组。粪检结果:阿苯达唑干混悬剂三个试验剂量组对羊消化道线虫虫卵转阴率分别为83.3%、93.3%和96.7%,减少率分别为95.2%、98.8%和99.9%;对原圆科线虫幼虫转阴率分别为63.3%、83.3%和93.3%,减少率分别为76.1%、87.5%和94.2%。剖检结果:三个剂量组对线虫的总计驱虫率分别为96.9%、98.3%和99.4%。阿苯达唑原料药15mg/kg剂量对羊消化道线虫虫卵转阴率、减少率分别为90%和98.5%,对原圆科线虫幼虫转阴率、减少率分别为83.3%和86.9%,总计驱虫率98.5%。绵羊能耐受80mg/kg剂量。试验证明:阿苯达唑干混悬剂的驱虫活性及安全性与阿苯达唑原料药、片剂等无明显差异,均有良好驱虫效果,临床驱除绵羊线虫使用剂量以15mg/kg为宜,干混悬剂使用方法简便,特别适用于高原牧区,具有推广价值。     

Emergence from inhibited development of cyathostome larvae in ponies following failure to remove them by repeated treatments with benzimidazole compounds

The effect of three albendazole treatments at 5-week intervals, beginning at turnout in April, on cyathostome infections in Shetland ponies was compared with the effect of sequential treatments with albendazole, oxfendazole and oxibendazole. The results showed a substantial reduction in faecal egg output after the first albendazole treatment. Since faecal egg counts remained very low, no estimation of the effect of the second treatment was possible. The third treatment with albendazole and oxibendazole was followed by an increase in faecal egg counts to values of greater than 100 eggs g-1 within 4 weeks. A final albendazole treatment in December, 1 week before necropsy, failed to reduce faecal egg counts. These results suggest resistance to albendazole and oxibendazole in the cyathostome populations of the ponies. The increase in faecal egg counts after the third anthelmintic treatment in July occurred, although overwintered pasture infectivity was very low. The most likely explanation for this increase is resumption of the development of worms which overwintered as inhibited larvae in the host.     

The Pharmacokinetics and Efficacy of Long-Term Low-Level and Split-Dose Administration of Albendazole Through In-Feed Formulations against Ovine and Caprine Parasitic Gastroenteritis

Two trials were conducted against natural and experimentally induced parasitic gastroenteritis in sheep and goats using an in-feed formulation of albendazole to evaluate its therapeutic and prophylactic efficacy. In the first trial, albendazole was incorporated in feed pellets to deliver an average daily dose of 0.7 mg/kg body weight in order to evaluate its prophylactic efficacy. In the second trial, feed pellets were offered to deliver an average total dose of 8.0 mg/kg body weight in two equal split doses in order to evaluate its curative efficacy.Sustained plasma concentrations of the active compound, albendazole sulphoxide, and its metabolite albendazole sulphone, sufficient to prevent establishment of infection, were achieved when the animals were allowed to feed on medicated pellets for 10 consecutive days. The bioavailability of the metabolites of albendazole following the administration of a therapeutic dose in two split doses of the in-feed formulation was sufficient to remove established adult nematodes. The concentrate feed pellets could be used for self-medicating small ruminants for therapeutic use as well as for prophylaxis based on their strategic use appropriate to the epidemiology of the parasitic disease.     

牦牛脑多头蚴病药物治疗试验

用丙硫咪唑和吡喹酮两种驱虫药物,采用"药物增量法"和"药物联合法"对24头具有明显临床症状的脑多头蚴病例牦牛进行不同剂量治疗试验.结果表明,吡喹酮增量法治疗后症状消失时间最短,为8.5 d;丙硫咪唑增量法有效率和治愈率均为100%,吡喹酮增量法的有效率80%,治愈率70%;丙硫咪唑和吡喹酮联合法的有效率67%,治愈率50%.对照组10头脑多头蚴病牦牛均在不同时间内死亡.     

The anthelmintic effect of aqueous methanol extract of Combretum molle (R. Br. x. G. Don) (Combretaceae) in lambs experimentally infected with Haemonchus contortus

The aqueous methanol extract from the stem-bark of Combretum molle was evaluated for anthelmintic activity in lambs infected with Haemonchus contortus using faecal egg count (FEC) reduction assay. The extract showed a dose-dependent reduction in FEC in infected animals. At doses of 500, 1000 and 2000 mg kg(-1), the extract caused FEC reduction of 63%, 69.25% and 96.23%, respectively. Similarly, the standard anthelmintic (albendazole) at a dose of 200 mg kg(-1) produced FEC reduction of 99.24%. FEC reduction produced by the extract at doses of 500 and 1000 mg kg(-1) is below the minimum standard of 90% FEC recommended by the World Association for the Advancement of Veterinary Parasitology (WAAVP). However, there was no significant (P>0.05) difference between the means of groups treated with 1000 mg kg(-1) and 2000 mg kg(-1) compared to that of albendazole. In this study, C. molle has shown a promising anthelmintic activity against experimental haemonchosis. Nonetheless, further studies to evaluate its detailed toxicity are required for the plant extract to be developed into a useful anthelmintic drug. There is also the need to evaluate other parts of the plant (root, leaves, fruits, etc.) for the same effect.     

Comparative Anthelmintic Activity of Strategic Sustained Low-level Administration of Albendazole in Feed Pellets Compared to Single Doses of Closantel and Tetramisole against Natural Ovine Parasitic Gastroenteritis

The strategic use of single therapeutic doses of closantel, tetramisole or sustained low-level administration of albendazole in feed pellets in controlling naturally acquired parasitic gastroenteritis in sheep was investigated on a farm in semi-arid Rajasthan, India. A total of 303 5- to 6-month-old sheep were divided into three groups. Two groups were dosed with single therapeutic doses of closantel and tetramisole and the third group was given a low-level medication with albendazole through feed pellets for 30 days. Faecal egg counts revealed significantly lower counts (p<0.001) in the group treated with closantel compared to the other two groups. The faecal egg counts in the group receiving sustained low-level albendazole rose after withdrawal of the medication but remained significantly lower than those in the group treated with tetramisole up to 7 weeks after treatment (p<0.05). On the other hand, in the group treated with tetramisole, the mean faecal egg count rose from 3 weeks after treatment and remained continuously higher than those in any other group up to 12 weeks after treatment. The closantel-treated group gained more body weight but the first six-monthly greasy fleece yield was greater in the group treated with medicated pellets. During the first 3 months of the experiment, three animals in the group treated with tetramisole died of parasitic gastroenteritis. Following sustained low-level administration of albendazole in feed pellets, the plasma disposition curve of both the sulphoxide and sulphone metabolites reached its plateau level by day 5 and remained almost constant thereafter. The comparative cost-effectiveness of the three treatment regimes during the first 3 months of treatment was best for the group treated with closantel followed by the group treated with medicated feed pellets.     

The effect of pest control on the incidence of trichinosis in Virovitica-Podravina County, Croatia

The aim of the study was to assess the role of pest control as a preventive measure in the control of trichinosis. The investigation was designed as a retrospective cohort study in the Virovitica-Podravina County. The incidence of trichinosis was determined according to the presence or absence of exposure to protective pest control measures. Differences in the rate of trichinosis infection were determined by calculating relative risk (RR), i.e., the ratio of absolute risk in the two groups. In this epidemiological study, data collected in the County area regularly covered by pest control (exposure area) were compared with other areas not covered by regular pest control measures (non-exposure area). The study included 132 subjects living in the County and locally infected with trichinosis. Patient data were obtained from their medical history, epidemiological survey and epidemiological questionnaire on the source (autochthony) of the disease. The study also included 133,028 domestic pigs, 875 wild animals (mostly wild boar) and 111 trapped rats. All samples were examined by the method of trichinoscopy at authorized veterinary institutions of the County. Trichinosis infection was recorded in 1012 of 79,534 domestic pigs in the area exposed to pest control measures and in 51 of 53,494 domestic pigs from the rest of the County. RR for the exposure area vs. non-exposure area was 13.35 (95% CI 10.08-17.68; p<0.05); according to particular areas, RR was 3.66 (95% CI 2.62-5.13) for Pitomaca, 22.47 (95% CI 13.27-38.08) for Slatina and 118.89 (95% CI 29.7-476.01) for Orahovica (p<0.05 all). Domestic pigs from the County areas exposed to regular pest control measures had a 13-fold likelihood of infection recorded in pigs from County areas where pest control measures were not or were only occasionally performed. Quite unexpectedly, these results revealed a failure of pest control to reduce the incidence of trichinosis. The spread of trichinosis obviously occurs by some routes obviating the impact of pest control.     

Modulations of bovine hepatic microsomal metabolism of benzimidazoles by secondary plant metabolites

The study was aimed to estimate the effect of plant secondary metabolites present in ruminants diet and phytogenic feed additives on liver microsomal metabolism of albendazole and fenbendazole. The selected phytocompounds comprised of flavonoids (apigenin, quercetin) and saponins (hederagenin, medicagenic acid). The experiments were performed on liver microsomal fraction obtained from routinely slaughtered cows. The intensity of albendazole and fenbendazole metabolism in the presence of flavonoids and saponins was analyzed in equimolar concentration (100 μM). The obtained results revealed that both flavonoids and saponins intensify the metabolism of albendazole and fenbendazole in bovine microsomes. In the case of albendazole, apigenin and quercetin doubled the amount of degraded drug and the amount of produced albendazole sulfoxide. Additionally, both flavonoids increased the amount of produced albendazole sulfone. Saponins, hederagenin, and medicagenic acid intensified the degradation of albendazole (1.8‐fold) and the production of albendazole sulfoxide (twofold). Medicagenic acid inhibited the production of albendazole sulfone. In the case of fenbendazole, the degradation of the drug and the production of oxfendazole were increased four and five times in the presence of saponins and flavonoids, respectively. The enhancement of benzimidazoles’ metabolism caused by the studied plant metabolites could change pharmacokinetics and the efficacy of benzimidazoles’ treatment in cattle.     

The efficacy of fenbendazole and albendazole against immature and adult stages of benzimidazole-resistant sheep trichostrongylids

The efficacy of two recently introduced benzimidazole anthelmintics, albendazole and fenbendazole, was determined for six-day, 10-day and adult stages of resistant strains of Haemonchus contortus and Trichostrongylus colubriformis. Albendazole, at 3.8 mg/kg reduced H contortus worm counts by 92.4, 70.8 and 67.1 per cent while fenbendazole, at 5.0 mg/kg, reduced worm burdens by 51.7, 95.5 and 93.4 per cent against six-, 10- and 25-day-old parasites respectively. For T colubriformis, the corresponding reductions with albendazole were 97.7, 95.8 and 64.9 per cent and for fenbendazole 29.0, 66.3 and 33.4 per cent. Compared with susceptible strains of H contortus and T colubriformis, for which therapeutic doses of benzimidazole anthelmintics are generally highly active against all stages of development, the present results show that these drugs do not have a uniform level of activity against all developmental stages of resistant strains.     

Influence of Diet Type and Pretreatment Fasting on the Disposition Kinetics of Albendazole in Sheep

The influence of the quality and quantity of diets on the disposition kinetics of albendazole were studied in sheep in two different experiments. The plasma concentration profiles of albendazole sulphoxide and albendazole sulphone were measured following intraruminal administration of albendazole at 5.0 mg/kg body weight in weaner sheep offered three different diets: 100% green Sorghum spp., 100% dry mature Cenchrus ciliaris hay and a 50:50 mix of these two diets. The peak plasma concentrations and the availability of the albendazole metabolites, as measured by the area under the concentration–time curve, were significantly higher (p<0.01) in the animals offered exclusively dry fodder compared to other diets. Changing the diet from dry to green fodder resulted in a significantly lower systemic availability of the drug metabolites. It is suggested that a decreased transit time of the digesta in the bowel on the green diet, with its high water content, limited the systemic availability of the drug by reducing the time available for gastrointestinal absorption.An experiment on the influence of different levels of pretreatment fasting on the pharmacokinetics of albendazole revealed significantly higher (p<0.05) plasma concentrations of the anthelmintically active sulphoxide metabolite from 12 h onwards following administration of the drug in animals subjected to 24 h of pretreatment fasting compared to other groups with pretreatment fasting of 8, 12 or 18 h. The area under the concentration–time curve and the minimum residence time of the drug metabolites were significantly greater (p<0.05) in animals that had been fasted for 24 h. It is suggested that fasting induces a decrease in the flow of digesta through the gastrointestinal tract of ruminants and prolongs the duration of dissolution of the drug, resulting in enhancement of the absorption of albendazole and of the systemic availability of its metabolites.