Effect of decoquinate on the control of coccidiosis in young ruminating calves

Twenty-five 6-week-old Holstein male calves were each inoculated with 500,000 sporulated oocysts of Eimeria bovis. Two nontreated (control) and 3 treated calves (1.5 mg of decoquinate/kg of body weight in feed) were necropsied 7 days after inoculation. Similar groups of calves were necropsied at 12, 18, 22, and 28 days after inoculation. Treated calves were started on medicated feed 2 days before inoculation or at 7, 12, or 15 days after inoculation or were on continuous medication from the day of inoculation. Control calves were not given medication. Early schizonts were in the small intestines of control calves at 7 days after inoculation, but none was in the treated calves that were started on medicated feed 2 days before inoculation. Schizonts were present in the small intestine of both treated and control calves at 12 days after inoculation. At 18 days after inoculation, control calves had schizonts in the small intestine and gamonts and oocysts in the cecum and large intestines, but treated calves only had schizonts in the small intestine. At 22 days, control calves had schizonts in the small intestine and gamonts and oocysts in the large intestine; treated calves had schizonts in the small intestine. At 28 days, controls still had schizonts in the small intestine and gamonts and oocysts in the cecum and large intestine; the treated calves that had been on continuous medication did not have schizonts, gamonts, or oocysts in the tissues. Decoquinate apparently kills sporozoites or arrests development and release of merozoites from the schizonts when fed at 1.5 mg/kg of body weight in the feed.     

球虫病的防制

球虫病是一种分布很广的原虫病。由于其对养禽业的重要影响,几十年来,广大科学工作者一直在寻求控制此病的有效方法。目前,已广为应用的有药物疗法、免疫接种及联合疗法。现扼要综述如下,以便广大养禽者在选择防制策略时借鉴。1药物疗法药物疗法是目前公认的防治球虫?..     

新形势下兔球虫病的防控措施

兔球虫病是养兔业常见及危害最严重的一种寄生虫病,给养兔业造成巨大的经济损失,幼兔感染严重者甚至引起死亡,成年兔一般呈耐性感染.目前兔球虫病的防控主要以药物防控为主,不合理的抗球虫药物使用容易导致虫株耐药性、药物残留和毒性等问题的出现.随着减抗、替抗和禁抗养殖的持续推进,本文介绍可行的化学药物、中药、微生态制剂和饲养管理...     

Alteration of neutrophil function associated with coccidiosis in cattle: influence of decoquinate and dexamethasone

Twenty Holstein steers subclinically infected with coccidia were allotted to 2 groups of 10 steers each. One group received a diet containing 0.5 mg of decoquinate/kg of body weight. After 25 days on the diet, there was no difference between the groups in lymphocyte blastogenic responsiveness to mitogens; however, there were differences in neutrophil function. Lymphocytes from steers of the decoquinate-fed group had decreased random migration under agarose, enhanced cytochrome C reduction, and enhanced iodination activity. Other measures of neutrophil function evaluated (chemotactic index, Staphylococcus aureus ingestion, and antibody-dependent and -independent cell-mediated cytotoxicity) were not affected. After 30 days of decoquinate feeding, half of the cattle in each group received 5 daily IM injections of dexamethasone (0.04 mg/kg of body weight). The dexamethasone-treated steers from the group that did not have decoquinate in the diet developed clinical coccidiosis, whereas the decoquinate-treated steers remained clinically normal. Lymphocyte and neutrophil function were again evaluated for a 3-day period beginning 4 days after dexamethasone treatment was halted. Neutrophils from the steers that developed clinical coccidiosis after dexamethasone administration had significantly (P less than 0.05) inhibited random migration under agarose, cytochrome C reduction, and iodination activity, but significantly (P less than 0.01) enhanced S aureus ingestion. The feeding of decoquinate prevented the inhibition of neutrophil cytochrome C reduction and lessened the inhibition of neutrophil iodination in the dexamethasone-treated group. Dexamethasone treatment was associated with an inhibition of lymphocyte blastogenic responsiveness to phytohemagglutinin in principals as well as controls.     

羊球虫病的研究进展

羊球虫病是由艾美耳属球虫引起的一种呈世界性分布的肠道原虫病,能引起羊腹泻、渐进性消瘦、贫血、发育不良,甚至发生死亡,羔羊发病率和死亡率较高,给山羊生产业和绵羊生产业造成巨大的经济损失。本文就羊球虫病的病原种类、流行病学特点、临床症状和病理变化、诊断、防治等方面的研究进展进行了综述。     

Evaluation of lasalocid and decoquinate against coccidiosis resulting from natural exposure in weaned dairy calves

Eighteen female Holstein calves, raised as natural herd additions under conditions typical of a well-managed midwestern United States dairy farm, were used in a natural-exposure study to determine the anticoccidial efficacies of lasalocid and decoquinate. Calves were allotted to 6 treatment blocks of 3 calves each as they were weaned. Within each block, calves were randomly assigned to be given either lasalocid or decoquinate or to remain as a nonmedicated control. Calves were given medication for 90 days and remained separated from other calves for 120 days. Adjusted weight gains were consistently greater in calves that were given medication; however, differences were not statistically significant. Fecal specimens were obtained from calves at weekly intervals during the study. Overall, oocyst shedding was low. During the medication period, quantitative mean fecal shedding of oocysts was reduced eightfold in calves given decoquinate and four-fold in calves given lasalocid, as compared with nonmedicated control calves. During the period following the medication period, calves that had been controls shed fewer oocysts than did calves that had previously been given medication. A pairwise comparison of the proportion of specimens that were oocyst-positive was made to assess qualitative oocyst shedding among treatment groups. During the medication period, qualitative oocyst shedding (all species, Eimeria bovis, E zuernii, species other than E bovis and E zuernii) was greater in controls than in either lasalocid-or decoquinate-treated groups. Like-wise, lasalocid-medicated calves shed oocysts more frequently than did the decoquinate-medicated group. After medication, qualitative findings were reversed. Little diarrhea was noticed in treatment or control calves during the study.(ABSTRACT TRUNCATED AT 250 WORDS)     

鸡球虫病的防治

鸡球虫病是危害养鸡业的主要寄生虫病,发病率高,对药物产生耐药性快,在实际生产中因投药不当而使该病暴发,给养鸡业带来巨大的经济损失。     

癸氧喹酯干混悬剂对不同地区分离球虫株的敏感性试验

分别进行癸氧喹酯对历史分离球虫株和现行临床分离球虫株的敏感性试验,结果显示,癸氧喹酯干混悬剂对历史分离球虫株和现行临床分离球虫株的敏感性较好,抗球虫指数大于180,表现出高效的抗球虫活性,能有效提高鸡只生长性能,提高饲料转化率。     

鸡球虫病的防治

本病是由多种球虫寄生于鸡肠道中引起的一种原虫病,是全世界普遍发生、威胁封闭式工厂化养鸡发展的一种重要的疾病。除引起雏鸡死亡外,病愈鸡长期不能康复,生长、发育、增重、产蛋都受到严重影响。     

Consumption of Pistacia lentiscus foliage alleviates coccidiosis in young goats

Coccidiosis near weaning is a major cause of diarrhea, ill-thrift, and impaired performance in small ruminants. A recent survey showed that in villages of the Samaria Hills, Israel, shepherds treat young, weaned goat kids afflicted with diarrhea by cutting and feeding them the foliage of Pistacia lentiscus L. (lentisk) or by tethering them close to lentisk bushes which they browse. The aim of the present study was to assess whether lentisk leaves do indeed have anti-coccidial value, and, if positive, to ascertain the role of tannins in this effect. We monitored for 24 (Experiment 1) and 30 (Experiment 2) days the effect of lentisk feeding on the development of naturally occurring coccidiosis in weaned kids artificially infected with parasitic nematodes. In Experiment 1, kids were infected with nematodes and fed lentisk foliage (PIS) or cereal hay (HAY). Coccidiosis developed at the early stage of the nematode infection, when dietary treatments were initiated. Kids in the PIS group had a lower (P<0.02) concentration of oocysts per gram feces (opg). In Experiment 2, aimed at verifying if tannins are the active component in lentisk foliage, coccidiosis occurred at the peak of the nematode infection, before experimental diets were initiated. Dietary treatments were: cereal hay (HAY), or lentisk foliage consumed without (PIS) or with (PISPEG) a 20-g daily supplement of polyethylene glycol (PEG; MW 4000), a molecule that impairs tannin-bonding with proteins. Goats fed the PIS diet had lower fecal opg counts than counterparts of the HAY (P<0.001) and PISPEG (P<0.002) treatments. Fecal opg counts for the HAY and PISPEG treatments did not differ, suggesting that the anti-coccidial moiety in lentisk was indeed tannins. Our results strongly suggest that: (i) in agreement with the ethno-veterinary anecdotal evidence, exposure of young, weaned goat kids to lentisk foliage alleviates coccidiosis; and (ii) this positive effect is associated with tannins. As coccidiosis is a major affliction of kids, providing them with tannin-rich browse near weaning could be an environmentally friendly way of improving their welfare and health status, in particular under bio-organic farm management.     

绒山羊缺硒症并发附红细胞体病的诊治

辽阳县兰家镇饲养户王某绒山羊存栏150只,2005年4月底开始产羔,至6月初共产羔40只.羊羔生下时皆正常,出生7 d后出现吮奶无力,四肢站立不稳、打晃,连续3 d不吃不喝、消瘦、拉稀,皮肤苍白,最后死亡.6月初到市动物防疫站门诊就诊,经临床剖检、化验室检验确诊为缺硒症并发附红细胞体感染.     

Experimental bovine coccidiosis: control with monensin

Young Holstein-Friesian bull calves were used in a controlled experiment to evaluate the efficacy of monensin against coccidiosis. The calves were given oocysts of Eimeria bovis and/or E. zurnii. Medication was started 3 days prior to inoculation and continued during the 30-day experimental period. Oocyst shedding was quantified prior to and throughout the experiment and demonstrated that monensin at the rate of 20 or 30 g ton-1 of feed significantly reduced oocyst shedding and clinical coccidiosis. Clinical infection with E. zurnii was very difficult to establish, even when calves were treated with 20 mg dexamethasone IM on Days 12, 15, and 16 post-inoculation.     

雏鸵鸟球虫病的诊断与防治

鸵鸟球虫病是由一种或多种球虫寄生在消化道上皮细胞内所引起的一种原虫病。该病在俄罗斯、纳米比亚等国家均有报道 ,而且引起很大的经济损失 ,主要危害雏鸟 [1] 。 1 999年 5— 6月份 ,湘南某鸵鸟养殖场饲养的雏鸵鸟发生了球虫病。经采用药物治疗及加强饲养管理和搞好环境卫生     

鸡球虫病免疫防治策略研究进展

鸡球虫病是一种呈世界性分布的原虫病,给养禽业造成严重的经济损失,据统汁包括防治该病所花的药费在内全世界每年损失约80亿美元,仅美国一年损失就高达45亿美元[1].     

The history of decoquinate in the control of coccidial infections in ruminants

Taylor, M. A., Bartram, D. J. The history of decoquinate in the control of coccidial infections in ruminants. J. vet. Pharmacol. Therap.  35 , 417–427. Decoquinate is a quinolone derivative that has been used for over 20 years in the control of coccidiosis in domestic ruminants. Decoquinate treats coccidiosis in lambs and calves and prevents coccidiosis in lambs when administered in feed at a dosage of 1 mg decoquinate/kg bodyweight (b.w.) daily for at least 28 days. It prevents coccidiosis in calves and aids in the prevention of coccidiosis in lambs when administered in calf and ewe feed, respectively, at a dosage of 0.5 mg/kg b.w. daily for at least 28 days. Decoquinate also aids in the prevention of abortions and perinatal losses owing to toxoplasmosis by medication of ewe feed at a dosage of 2 mg/kg b.w. daily, fed continuously for 14 weeks prior to lambing. Several field studies have reported reductions in cryptosporidial oocyst shedding. Decoquinate acts early in the life cycle of Eimeria on sporozoites, released from ingested oocysts, and on first‐generation meronts, arresting development and release of merozoites and thus preventing further damage to the intestines owing to the gametocyte stages. Production benefits associated with the use of decoquinate are due mainly to its action as a coccidiostat rather than any effects on diet utilization or ruminal fermentation.     

中西医结合防治兔球虫综合症

2003年夏天以来,我县熊家庙乡及周边地区饲养的毛用兔流行一种以粪便呈橘红色且带泡沫,颈部麻痹、瘫痪、惊叫,死亡率不断增加为特征的肠道疾病。大多数养殖户误认为是小肠球虫病,但用抗球虫药治疗效果不佳。我们根据临床症状和剖检变化分析该病     

鸡球虫病的流行现状及综合防控

鸡球虫病是一种发生普遍、严重危害养鸡业的疾病之一.不同品种、不同日龄的鸡均具有易感性.在各种鸡病中球虫病的发病率最高,约占1/6～1/5.本病主要侵害1～3月龄的雏鸡,特别是地面平养的肉鸡最易感,发病率高,死亡率可达60%以上.随着规模化、集约化养殖的发展,本病的危害日趋严重.因此,如何防治本病是目前养鸡业所面临的重要课题之一.     

Immunity to sarcocystosis: Modification of intestinal coccidiosis,and disappearance of sarcocysts in dairy goats

Fifty, 2–3 month old dairy goats were each vaccinated orally with 10000 sporocysts of Sarcocystis capracanis and 25 age-matched goats served as uninoculated controls. Groups of vaccinated and control goats were challenged with lethal doses of S. capracanis at 95, 113, 205, and 274 days post-vaccination. Vaccinated goats developed subclinical sarcocystosis. Twenty-three vaccinated goats and 1 control goat died of intestinal coccidiosis and bacterial pneumonia, 15–118 days after vaccination. Myositis and degenerating sarcocysts were seen in muscles of goats necropsied at 90–186 days postvaccination. Very few, or no sarcocysts were seen in goats necropsied at 272 and 332 days post-vaccination. Vaccinated goats survived a lethal challenge inoculation indicating persistent protective immunity.