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。     

伊维菌素注射剂对绵羊羊狂蝇蛆的驱除效果研究

应用伊维菌素注射剂,选择自然感染羊狂蝇蛆的绵羊80只,分别按0.1、0.2和0.3 mg/kg体重皮下注射,进行驱除效果观察,同时设阳性对照组。结果表明,伊维菌素注射剂0.2、0.3 mg/kg剂量组对羊狂蝇蛆的驱净率和驱虫率均达100%;0.1 mg/kg剂量组的驱净率为90.0%、驱虫率为97.7%。试验结果证明伊维菌素注射剂3个试验剂量驱除羊狂蝇蛆均高效安全,且使用0.2 mg/kg剂量可达100%的驱除效果。     

伊维菌素浇泼剂对绵羊狂蝇蛆的杀灭效果观察

应用伊维菌素浇泼剂对感染羊鼻蝇幼虫的249只绵羊进行驱治试验,并留30只感染羊作为阳性对照组,投药后33～37d剖检。结果：阳性对照组羊鼻蝇幼虫感染率为53．33％,平均感染强度9．5（4～17）：伊维菌素浇泼剂对感染羊鼻蝇幼虫的驱净率97．62％,驱虫率98．74％。     

伊维菌素注射液防治牦牛牛皮蝇感染的疗效观察

应用伊维菌素分别给4组牦牛给药进行驱虫效力研究。结果表明:对照组牛皮蝇蛆感染率为64%,第1组、第2组、第3组分别为28%、9%、0%。伊维菌素防治第3组牛驱净率和驱虫率均达100%,第1组和第2组驱净率和驱虫率分别为87%、100%、94.6%和100%。连续3次隔月注射伊维菌素注射液可以有效防治牛皮蝇。     

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...     

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。     

微量伊维菌素注射剂对牦牛皮蝇幼虫的驱除效力试验

选择当年犊牦牛154头,9月下旬用伊维菌素注射液分别按2,5,10,20μg/kg剂量注射给药,进行牦牛皮蝇幼虫的驱除效力试验,翌年3月中旬和5月下旬检查防治效果。结果:2μg/kg剂量组的平均驱净率为90.32%,平均驱虫率93.76%,5,10,20μg/kg剂量组感染率为0,驱净率和驱虫率均达100%。试验证明:伊维菌素注射液微量驱除牛皮蝇幼虫高效安全经济,最佳剂量为5μg/kg。     

羊狂蝇幼虫药物防治试验及最佳防治时间的选择

本文依据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、气候地区羊狂蝇成蝇出现及消失时间等活动规律的观察结果,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的效果比较试验。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。     

多拉菌素和伊维菌素对牛、羊寄生虫的驱虫效果研究

目的:研究多拉菌素、伊维菌素对高寒阴湿地区放牧牛、羊寄生虫的驱治效果。对甘肃省张家川回族自治县林缘区7个试验点的42头牛、280只羊为研究对象。方法:按多拉菌素给牛0.3 mg/kg体重、羊0.2 mg/kg体重,伊维菌素给牛、羊均以0.02 m L/kg体重通过皮下或肌肉注射给药,以全身蠕虫剖检法及EPG来判定驱虫率。结果:发现相对于空白对照组来说,用药后多拉菌素组、伊维菌素组驱虫效果明显。结论:多拉菌素、伊维菌素对高寒阴湿地区牛、羊寄生虫均有较好的驱治效果,其中多拉菌素驱治效果最优。     

伊维菌素注射液对绵羊内外寄生虫驱除试验

用伊维菌素分低、中、高3个剂量组对60只绵羊进行了驱虫试验，结果表明，伊维菌素对绵羊鼻蝇的驱除率90％以上，虫卵减少率分别为82．4％、96．0％和96．4％。驱虫的最佳剂量为0．02ml／kg体重．     

Sheep oestrosis (Oestrus ovis Linné 1761, Diptera: Oestridae) in Sardinia, Italy.

Oestrosis, the nasal myiasis of sheep and goats, is caused by the larvae of Oestrus ovis L. 1758 (Diptera, Oestridae) that develop from the first to the third stage larva in the nasal cavities and frontal sinuses of affected animals. The authors report the results of an epidemiological study of oestrosis of sheep in Sardinia, Italy. Heads of 6-month to 10-year-old Sardinian sheep (n=566) from 124 free-ranging flocks were examined for the presence and location O. ovis larvae from December 1996 to November 1997. Larvae were collected, counted, and larval stages were identified. O. ovis larvae were found in 100% of examined flocks and in 91% (514/566) of examined sheep. The monthly prevalence ranged from 69% in May to 100% in July. First stage larvae were found in 82% (463) of all heads examined, second stage larvae in 65% (367) and third stage larvae in 10% (56). The majority of sheep harboured first stage larvae, with prevalences of over 80% throughout most of the study period. The prevalence of O. ovis found in this study of Sardinian sheep is the highest reported in the Mediterranean area. The high percentage of first stage larvae found throughout the entire study period may be due to a brief period of decreased rate of larval maturation, in particular in December 1996 (96%) and January-October 1997 (94%). Third stage larvae were consistently present, often however, with extremely low prevalences compared to total larval burden.     

Seasonal variation of Oestrus ovis-specific antibodies in sheep and goats mixed flocks in Greece

The aim of this survey was to investigate the year-round epidemiological patterns of Oestrus ovis ELISA sero-prevalence in sheep and goats kept together under the same husbandry system in an endemic area of Greece. Twenty-five adult female sheep and 25 adult female goats, coming from a large mixed flock, were randomly selected, eartaged and monthly blood sampled during 1 year period (November 1998-October 1999). Serological prevalence in sheep was 100% all around the year. Mean intensities of specific O. ovis antibodies follow a seasonal evolution with higher mean titers between March and July than in winter. In contrast, the serological prevalences in goats were low specially in winter months (from October to January). No significant difference were noticed in goats antibody levels during the year period. The possible reasons of this difference of O. ovis sero-prevalence between sheep and goats are discussed.     

Efficacy of ivermectin controlled-release capsules for the control and prevention of nasal bot infestations in sheep

Objective To investigate the therapeutic and prophylactic efficacy of an ivermectin controlled-release capsule against nasal bots (Oestrus ovis) in sheep.
Design Trial 1 – A pen study with controls. Trial 2 – A field study with controls.
Animals Trial 1 – Forty Merino wethers with natural infestations of nasal bot were used. Trial 2 – One hundred nasal bot-free wethers were used.
Procedure Trial 1 – Ten randomly selected animals were slaughtered and the heads split and examined to confirm bot infestation. Fifteen animals were allocated to untreated controls and 15 to treatment with a controlled-release capsule delivering ivermectin at ≥ 20 μg/kg/day for 100 days. Twenty-nine days after treatment the sheep were killed and examined for nasal bots. Trial 2 – Nasal bot-free sheep were allocated to two groups of 45 animals. One group was untreated the other sheep were treated with capsules as above. The sheep were grazed as a single group exposed to natural challenge from O ovis . Ninety days after treatment the animals were slaughtered and examined for nasal bot infestation.
Results Trial 1 – Live O ovis larvae were recovered from 60% of control sheep. No live larvae were collected from treated sheep. Trial 2 – Forty-one percent of untreated sheep harbored nasal bot infestations. No live larvae were collected from any treated animal.
Conclusion Treatment with a single ivermectin controlled-release capsule was 100% effective against existing infestations of O ovis and as a prophylactic treatment for this parasite.     

Oestrus ovis infestation of a dog in the UK

In March 2011, a dog on a sheep farm in the Cotswolds, UK, expelled a mature live third-stage larva of the sheep nasal botfly, Oestrus ovis, after a violent and traumatic sneezing episode. The dog had been infected with first-stage larvae deposited by an adult fly the previous autumn; larval development had progressed throughout the winter and spring with few apparent clinical signs and possibly masked by ongoing immunotherapy for an unrelated condition. Identification of the parasite at the Liverpool School of Veterinary Science was made from a submitted puparium, the "chrysalis" stage to which the larva had progressed within days of its expulsion from dog's nose. To the authors' knowledge this is the first report of nasal botfly infestation of a dog in the UK.     

Seasonal variations in the larval burden distribution of Oestrus ovis in sheep in the southwest of Spain

A chronobiological study of oestrosis was conducted for larval instars of Oestrus ovis from November 2000 to September 2002 with the examination of 477 adult sheep of the southwest region of Spain. Skulls from slaughtered sheep were examined and the different O. ovis larval stages (L1, L2, L3) were recovered from the nasal-sinus cavities. O. ovis larvae were detected in 339 sheep, reaching a prevalence of 71.1%. Only one farm was free of infested sheep indicating a prevalence of the 97.91% among studied flocks. The mean larval burden was 18.54 larvae per infested head during the coldest months in the southwest of Spain when the larval burden reached its highest levels, especially of the first larval stage (L1). However, the maximum percentage of L1 coincided with the minimum percentage of the second larval stage (L2). The third larval stage (L3) was observed in relatively low levels during the entered study period, but two peaks occurred in April-May and in September-October. During the 2 years of sampling, all the different larval stages were simultaneously recovered throughout the year, indicating the existence of a long favourable period for the evolution and development of the larval instars, which would start between February and March and finishing in November.     

Genetic structure of Oestrus ovis populations in sheep and goats.

A genetic analysis using RAPD markers was performed on 12 natural populations of Oestrus ovis (Linné, 1761). Three-hundred and six O. ovis larvae (first, second and third instars) were randomly recovered in nasal cavities of sheep and goats naturally infected in Algeria, Ethiopia, France, Mauritania, Rumania and Tunisia and were analysed by 56 RAPD fragments. The results showed a high diversity within all samples. A significant genetic divergence was showed by discriminant analyses among the 12 populations sampled (p<0.0001). Moreover, discriminant analyses showed significant differentiation (p<0.0001) between O. ovis larva populations of sheep and goats and also among samples collected in the same region.     

Experimental concurrent infection of sheep with Oestrus ovis and Trichostrongylus colubriformis: effects of antiparasitic treatments on interactions between parasite populations and blood eosinophilic responses

The purpose of this experiment was to determine if an earlier infection with Oestrus ovis would down regulate an infection with Trichostrongylus colubriformis when the larvae of O. ovis were expelled from the nasal cavities of sheep by a specific treatment. Three groups of five lambs were used: group 1 was artificially infected with O. ovis larvae and later with T. colubriformis, group 2 received O. ovis larvae and later was treated with ivermectin 14 days before being infected with T. colubriformis. Group 3 was infected with T. colubriformis only. The criteria examined were: the effects on nematode egg excretion, worm fecundity, nematode burdens and the kinetics of blood eosinophils. Significant decreases of nematode egg excretion, worm fecundity, nematode burdens were observed in group 1 compared to group 3. However, no changes were observed in either group 2 or 3. In group 2 it was noted that antiparasitic treatment induced a rapid decrease in blood eosinophils to a range close to the non-infected control group and this was associated with the removal of the down regulation effects of nematode burdens. This experiment showed that there is no cross immunity between O. ovis and T. colubriformis and that eosinophils may act against any parasite without specific priming.     

青藏高原藏羊狂蝇蛆的形态学观察

应用低倍显微镜和实体显微镜对采自青藏高原等地区的羊狂蝇一期幼虫、二期幼虫、三期幼虫的形态特征进行了详尽的观察并对不同海拔高度地区的样本的细微形态结构进行了比较,发现它们之间仅有较小的个体差异,其基本特征性形态显示一致,从而确认青海省的6个县市、甘肃省的3个县市的狂蝇蛆同属一种。     

Nasal myiasis in a cat caused by larvae of the nasal bot fly, Oestrus ovis

An 8-year-old desexed male Burmese cat, which lived on a sheep-grazing property in central New South Wales, Australia, was presented following the sudden onset of dyspnoea, moist coughing and violent sneezing. The respiratory distress started several hours after the cat had made an outdoor excursion. Anterior rhinoscopy demonstrated small, white objects moving across oedematous and moderately inflamed nasal mucosa. These were retrieved via a series of vigorous nasal flushes and subsequently identified as larvae of the nasal bot fly, Oestrus ovis. The cat was treated with ivermectin followed by selamectin 7 days later. It went on to make a complete recovery over 2-3 weeks.