贵德县羊狂蝇幼虫驱除效果比较及示范应用

选用阿维菌素和伊维菌素药物的不同剂型,分别在9月上旬和10月中旬选择自然感染羊狂蝇幼虫的绵羊200只,采用注射液口服、泼背和片剂口服的方法,对羊狂蝇幼虫进行药物驱除效果比较试验。结果表明:9月上旬驱虫组效果达100%,而10月份驱虫组效果不理想,通过驱虫比较试验的结果,于2012、2013年连续两年进行示范应用,驱虫效果仍保持高效稳定。     

高原羊狂蝇成蝇飞翔规律的观察及防治时间的确定

本文对我省黄河谷地的贵德县和高原腹地的玉树县两个不同海拔、气候地区对羊狂蝇成蝇出现及消失的时间进行了观察,结果表明:青海高原不同海拔地区羊鼻蝇飞翔(产虫)期均在每年的7月中下旬,差别只是较寒冷的高海拔地区产卵期出现较晚。依据这一成蝇飞翔产虫的活动规律,我们认为9月上旬是驱虫防治的最佳期。     

伊维菌素控制春乏期羊狂蝇蛆病试验

目的为有效预防和控制羊狂蝇蛆病的发生。方法选用伊维菌素在羊狂蝇成虫完全消失的11月进行驱杀羊狂蝇蛆试验,并以敌敌畏熏蒸作为对照。结果在来年羊狂蝇成蝇出现之前的长达7个月的冬春枯草季节,伊维菌素组驱虫率和驱净率均保持100％,而敌敌畏熏蒸组驱虫率保持94．69％,驱净率仅保持60％。结论选择每年11月份用伊维菌素驱虫一次,可使羊在冬春季节无任何阶段羊狂蝇幼虫寄生。     

共和县羊鼻蝇感染流行调查及其防治效果试验

采用询问当地长期放牧的40~65岁牧民和现场调查方法,对共和县3个乡镇羊鼻蝇发病情况进行了调查,并选择调查的3个地区有疑似被感染羊鼻蝇的放牧羊分为试验组和对照组,试验羊进行不同时间驱虫,观察不同驱虫时间防治效果。结果表明共和县羊狂蝇侵袭时间在每年的8月上旬到10月上旬,羊只发病后主要表现为羊只流出大量脓性粘稠且有时带血的鼻液,伴有打喷嚏、磨鼻、甩鼻、呼吸困难等症状,平均感染率为58.8%,     

共和县羊鼻蝇感染流行调查及其防治效果对比试验

采用询问当地长期放牧的40-65岁牧民和现场调查方法,对共和县3个乡镇羊鼻蝇发病情况进行了调查,并选择调查的三个地区有疑似被感染羊鼻蝇的放牧羊分为试验组和对照组,实验羊进行不同时间驱虫,观察不同驱虫时间防治效果.结果表明共和县羊狂蝇侵袭时间在每年的8月上旬到10月上旬,羊只发病后主要表现为羊只流出大量脓性粘稠且有时带血的鼻液,伴有打喷嚏、磨鼻、甩鼻、呼吸困难等症状,平均感染率为58.8%,经不同时间驱虫后平均发病率为24%,明显低于对照组实验羊平均发病率.     

国产伊维菌素注射液对绵羊羊狂蝇第一期幼虫的驱虫试验

国产伊维菌素注射液对绵羊羊狂蝇第一期幼虫的驱虫试验为了验证国产伊维菌素对绵羊体外奇生虫的驱虫效果，作者于１９９４年９月在西宁北川地区对当地绵羊外寄生虫的感染情况调查的基础上进行了本项试验，试验选羊狂蝇蛆病病羊１００只，试验药物为上海兽药厂产１％伊维菌...     

羊狂蝇蛆病的研究及防治概况

本文对若干年来省内外羊狂蝇蛆病的研究及防治概况进行比较、分析，文章表述了①狂蝇幼虫的生态及流行状况远比以前的记载复杂，特别在宁夏地区狂蝇蛆在一年四季羊体内有不同发育期的幼虫同时寄生；②初步证明伊维菌索是防治本病的首选药物。     

羊角钻孔注药驱治军鼻蝇

羊鼻蝇病是由羊狂蝇幼虫寄生于羊的鼻腔和与之相通的腔窦中而引起的一种羊寄生虫病.羊鼻蝇的驱治方法很多,但效果不一.鼻孔灌药法驱治,当药物达到鼻腔后,狂蝇幼虫为逃避药物的毒害向更深的腔窦中逃避,有的幼虫逃到了羊角的空腔内,有的甚至钻入脑内,引起羊只脑炎而死亡.     

伊维菌素干混悬剂对羊狂蝇蛆的驱杀效果试验

选择自然感染羊狂蝇蛆绵羊131只,分别按体重0.1,0.2和0.3mg/kg剂量口服伊维菌素干混悬剂,进行驱除效果观察,同时设空白对照组。结果表明,口服伊维菌素干混悬剂0.2,0.3mg/kg剂量组绵羊的羊狂蝇蛆驱净率和驱虫率均达100%。口服0.1mg/kg剂量组绵羊的羊狂蝇蛆驱净率93.9%、驱虫率98.6%。试验证明伊维菌素干混悬剂对羊狂蝇蛆驱虫效果明显,临床使用0.2mg/kg体重剂量高效安全。     

羊蝇蛆病防治

正羊蝇蛆病是由双翅目昆虫中的某些蝇类幼虫引起的寄生虫病,常见的有羊鼻蝇蛆病和伤口蛆病。1羊鼻蝇蛆病羊鼻蝇蛆病是由狂蝇属羊鼻蝇的幼虫寄生于羊的鼻道及附近窦腔引起的一种慢性鼻炎或鼻窦炎。1.1流行特点羊鼻蝇生长发育需经幼虫、蛹和成虫3个阶段。     

Parasites of domestic and wild animals in South Africa. I. Oestrus ovis in sheep

Separate groups of 3 oestrid-free lambs were exposed to infestation on irrigated pasture for periods of approximalely 33 days each over30 months, and on dry-land pasture for approxomately 42 days over a period of 18 months. With some exceptions, the lambs slaughtered from October-June were found to be infested with Oestrus ovis while, with one exception, those slaughtered from July-September were free. A minimum of 4 sheeps' heads, obtained weekly over 24 months from the Pretoria Municipal Abattoir, was examined for infestation. Of a total of 542 heads examined, 73,4% were infested, having a mean burden of 15,2 larvae. Mean larval burdens were slightly greater in hornless than in horned sheep in Dorper-type than in Merino-type sheep, and in lambs than in sheep with 2 or more permanent incisors. The largest larval burdens were recovered from sheep slaughtered during May and June and the smallest during September and October. The greatest number of 1st instar larvae were recovered during May and June and the smallest during September, but those recovered during the latter month were the largest. With one exception, mature larvae which pupated after 21 March or before 16 August failed to hatch as viable flies. Those which pupated after 16 August hatched as flies after a pupal stage of approximately 50 days and the first flies to hatch were invariably recovered during the first 2 weeks of October. The pupal stage decreased to approximately 25 days during December and January and increased again to approximately 50 days for flies hatching during May. No flies hatched between 18 May and 1 Cctober. The following life cycle ofr Oestrus ovis is suggested: sheep are repeatedly infested from October-June; thereafter infestation survives in the sheeps' heads until August, mainly as 1st instar larvae, then as pupae and larvae until fresh infestation takes place during October.     

Parasites of domestic and wild animals in South Africa. III. Oestrus spp. and Gedoelstia h?ssleri in the blesbok

Four blesbok culled in the Rietvlei Nature Reserve, Pretoria, District during May 1972 were found to harbour large burdens of 1st instar Oestrus spp. larvae and from 16-37 3rd instar larvae of Oestrus macdonaldi. They were also infested with large numbers of 1st instar Gedoelstia h?ssleri larvae but only 2 harboured 3rd stage larvae of this species. During an 18-month period 34 blesbok were culled in pairs in the Percy Fyfe Nature Reserve, Potgietersrus District. These antelope harboured peak numbers of 1st instar Oestrus spp. larvae during February, July and December but few if any during early October. Third instar Oestrus variolosus larvae were generally recovered from July-February and those of O. macdonaldi during July 1972 and from May-September 1973. Some 1st instar larvae of these flies appeared to undergo a pulmonary migration before returning to the naso-pharyngeal area to mature. The pupal period of O. variolosus varied from 67 days during the spring to 35 days during the summer. G. h?ssleri larvae reached peak numbers from October 1972-January 1973 and during May and June 1973. The lowest numbers were recovered from August-October 1973. Recovery and measurement of 1st instar larvae indicated that they either undergo an ocular-cranial or ocular-vascular-pulmonary migration before reaching the naso-pharyngeal area. Pupal periods varied from 46 days for flies hatching during October to 22 days for those hatching during December.     

Incidence of Oestrus ovis infestation in Borno-white Sahel goats in the semi-arid zone of Nigeria

Research conducted on the incidence of Oestrus ovis in Maiduguri showed that 53.8% of the 4,000 Borno-White Sahel goats examined were parasitised. The mean year-round infestation per goat was 2.03 larvae. Adult goats had a higher infestation rate than younger ones (60 versus 47.5%). Infestation rates for the females and males were 55.2 and 52.2%, respectively. Nevertheless there was no statistical significance between values for the different age and sex groups studied. Different larval stages were encountered throughout the year with a 3rd instar peak between May and September and a first instar peak from June to October suggesting a fly period between June and October.     

Prevalence and larval burden of oestrus ovis (Linné 1761) in sheep and goats in northern mediterranean region of France

A slaughterhouse survey to determine prevalence and larval burden of Oestrus ovis larvae in sheep and goats was performed monthly during one year in Pézenas, South of France, northern mediterranean region. A total of 1303 sheep and goat heads were selected at random. O. ovis larvae were found in 274 sheep out of 631 (43.4%), and the prevalence rate varied from 14.3% in February to 65% in October. The mean number of larvae in infected sheep heads was 10.86 with 9.24 L1, 0.91 L2 and 0.71 L3. One hundred and ninety-one goats out of 672 were infected (28.4%), and the prevalence rate varied from 6.25% in September to 47.1% in April. In infected goat heads, the mean parasitic burden was 5.35 with 4.04 L1, 0.73 L2 and 0.58 L3. These results confirm worldwide observations indicating that the prevalence and the parasitic burdens are less in goats than in sheep.     

Analysis of the humoral immune response to Oestrus ovis in ovine

Antibody responses (IgG, IgM and IgA) against Oestrus ovis were analyzed in sheep and in first year grazing lambs from Sardinia (Italy) by an indirect-enzyme-linked immunoassay test and L2 O. ovis excretory/secretory antigens. Serum samples from 208 sheep were obtained prior to be slaughtered, and then heads were removed and cut open along their longitudinal axis to collect the parasites from the nasal cavities, turbinates and sinus. Besides this, blood samples were monthly collected from the lambs of G-1 (maintained under field conditions) and the lambs of G-2 (kept housed since birth to avoid Oestrus infestations) throughout a year. In the sheep, a positive significant correlation was observed between the number of first instar O. ovis larvae and the values of IgM, and between the second instar larvae and the IgG optical densities. In the lambs, all classes of antibodies increased significantly from July in G-1. The highest values of IgG were reached in September (IgG) and decreased in November-December. The IgM response peaked in November, and very low values of IgA were observed during the study. Matching these data with chronobiology of O. ovis in this region, we conclude that the first infection occurs on May, stimulating the production of humoral antibodies. The reduction of the IgG antibody levels starting from October means the beginning of the diapause while the IgM response seems to be associated to the presence of L1 in the nasal cavities. The data obtained led us to forecast an early treatment of the ovine on June-July, which should keep away from the maturation of O. ovis L1 larvae, avoiding the development of clinical lesions and interrupting the life cycle of this parasite.     

Parasites of domestic and wild animals in South Africa. XLVI. Oestrid fly larvae of sheep, goats, springbok and black wildebeest in the Eastern Cape Province

Merino sheep in Thornveld, Dorper sheep and Angora goats in inland Valley Bushveld, Angora goats and Boer goats in Valley Bushveld on the coastal plateau, and springbok, Antidorcas marsupialis, and black wildebeest, Connochaetes gnou, in Karroid Mountainveld, all in the Eastern Cape Province, were examined for the larvae of nasal bot flies. The sheep and goats were infested with the larvae of Oestrus ovis, and Dorper sheep and Boer goats harboured more larvae than Angora goats on the same farms. Most infestation was present from November to May in Merino sheep in Thornveld, from February to June in Dorper sheep in inland Valley Bushveld, and from May to September in Angora and Boer goats in Valley Bushveld on the coastal plateau. These patterns of seasonality appeared to be regulated by the severity of the summer temperatures at the various localities. The springbok were infested with the larvae of Rhinoestrus antidorcitis, most of which seemed to mature from June to August. All larval sages of Oestrus variolosus and Gedoelstia h?ssleri were present in the black wildebeest, and large numbers of 1st instar larvae of G. h?ssleri appeared to accumulate on the dura of the wildebeest from June to August.     

Epidemiology of <Emphasis Type="Italic">Oestrus ovis</Emphasis> infection of sheep in northeast Spain (mid-Ebro Valley)

Slaughterhouse surveys to determine the prevalence and intensity of larval Oestrus ovis Linnaeus (Diptera: Oestridae) in sheep, were conducted monthly for 1 year in northeastern Spain. The prevalence of O. ovis in 120 sheep in northeast Spain was 84.2%. The monthly prevalence ranged from 62.5% in January to 100% in June and October. Of the 3,831 larvae collected, 3,005 were first instar larvae (78.4%), 744 second instar larvae (19.4%), and 82 third instar larvae (2.1%). The mean larval burden per infected sheep was 37.9, throughout the year although infection was higher in October. The high number of first stage larvae in winter (especially October, November, and December) may be due to a period of slower larval maturation. Third-stage larvae were always present but sometimes in very low numbers compared to the total. According to the results, oestrosis appears to be a serious problem in the region.     

Towards a lower prevalence of Oestrus ovis infections in sheep in a temperate climate (south west France)

Oestrus ovis larvae are obligatory parasites of the nasal and sinus cavities of sheep and goats. In the temperate climate of western Europe, fly attacks occur between May and October and the first stage larvae arrest their development within the host between October and February. Oestrosis clinical signs such as nasal discharge and sneezing are well known by sheep breeders in southwest France. According to veterinarian recommendations, most of them treat their animals with long lasting fasciolicides once a year at least, mainly during the fly activity period and at the beginning of the hypobiotic period (when the parasitic population is only constituted of larvae). The consequences of these therapeutic programs were analysed in a local slaughterhouse by larval counts. Both prevalence and intensities of O. ovis infections decreased between 1989-1991 (before the use of systematic treatments) and 1996-1998 (after the spread of these treatments). The use of systematic treatments during the fly activity period and the beginning of the hypobiotic period seems to be very efficient in O. ovis control and could theoretically lead to a possible 'eradication' program as with cattle hypodermosis. Nevertheless the presence of parasites in apparently healthy goats, the possibility for a fly generation to develop before the first treatment in July-August and the succession of several fly generations all around the year in southern Mediterranean and tropical countries will maintain O. ovis infections. Furthermore, there are increased concerns about drug residues on consumer health and environment and this is the basis for the prospect of alternative strategies in O. ovis control.     

Parasites of comestic and wild animals in South Africa. II. Oestrus ovis in goats

During a period of 13 months, 130 goats' heads, obtained form the Johannesburg Municipal Abattoir, were examined for infestation with Oestrus ovis. Investation was present in 73,8% of the heads and the mean burden comprised 4,4 larvae. Such a small nuber of larvae were present that no clear seasonal incidence pattern could be determined. Pupal periods could be as long as approximately 60 days for flies hatching during October and May and as short as approximately 24 days for those hatching from December-February. The findings are compared with those obtained from surveys in sheep in south africa.     

Strongylid parasites of horses: experimental ecology of the free-living stages on the Canadian prairie

Each month for a 1-year period (October through September), equine fecal masses containing eggs of strongylid nematodes were placed outdoors on small grass plots in Saskatchewan, Canada. Thereafter, feces and grass from the plots were sampled after intervals of 1 week or longer, and the strongylid eggs and larvae recovered were counted. These observations were made over a 2-year period. Development of eggs to infective larvae occurred in all experiments, except those established in October, December, and January. Infective larvae from experiments set up in April through September survived that winter. During the summer, there was a gradual build up of infective larvae in the fecal masses, which reached a peak in August and September and then decreased into the winter. These results are discussed in the context of the control of strongylid parasites of horses on the Canadian prairie and in other areas of the world with a similar climate and similar horse management practices.