共查询到20条相似文献，搜索用时 218 毫秒
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应用害获灭注射剂按0.2 mg/kg体重剂量皮下注射给药,对自然感染痒螨的病羊进行治疗效果观察,并设空白对照组.结果表明,对感染绵羊痒螨的病羊进行2次用药治疗,即第1次用药后间隔10 d进行第2次用药,可完全杀灭绵羊痒螨,治愈率达100%,对未感染羊进行预防注射,可阻止痒螨的传播. 相似文献
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应用伊维菌素片剂,对自然感染绵羊痒螨的29只病羊进行治疗效果试验,并设阳性对照组.结果:伊维菌素治疗组绵羊在用药后48～72 h,瘙痒症状明显减轻,用药后21d检查,未查到活的痒螨.试验表明,伊维菌素0.2mg/ks体重剂量对初期感染绵羊痒螨的病样一次给药即可治愈;对严重感染者间隔7～10d再次给药具有良好的杀螨效果. 相似文献
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对自然感染寄生线虫和痒螨的绵羊用爱普瑞克制剂进行驱杀疗效观察.通过虫卵和瘁螨检查确定阳性羊,设爱普瑞克0.05、0.1、0.2 mg/kg体重3个剂量组,同时设阿维菌素0.2 mg/kg体重和空白对照组,经羊皮下注射药物.结果表明,爱普瑞克按0.2 mg/kg体重和阿维菌素0.2 mg/kg体重驱杀绵羊瘁螨杀净率均达100%,寄生线虫虫卵转阴率、卵减率都达100%.而爱普瑞克0.05 mg/kg体重,0.1 mg/kg体重驱治效果差,螨虫杀净率为53%～80%,且用药后第20天瘁螨病复发;寄生线虫虫卵转阴率、卵减率只有30%～80%.0.2 mg/kg体重为爱普瑞克驱杀绵羊寄生线虫和痒螨最低有效剂量. 相似文献
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羊螨病也称疥癣病,由痒螨、疥螨、蠕形螨等在绵羊或山羊皮肤或皮肤内寄生所引起的接触感染,具有高度传染性,是危害羊最严重的寄生虫病之一。以皮疹、皮炎、脱毛和搔痒为特征,常导致生长发育不良,贫血消瘦,乃至死亡。1病原及生活史螨属于无脊椎动物,节肢动物门,螨亚纲的动物,已知约5万种。羊螨的病原大多为痒螨、疥螨、蠕形螨,疥螨对山羊危害严重,而痒螨较易感染绵羊。疥螨寄生于皮肤角质下,虫体在隧道内不断发育和 相似文献
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<正>家畜螨病主要是由疥螨科的疥螨和痒螨科的痒螨以及足螨寄生于家畜（牛、羊、猪、兔和马）皮肤的表皮内外所引起的,经接触感染与传播的常见外寄生虫病。该病严重危害家畜的健康,增加养殖成本,可给养殖业造成巨大的经济损失。1流行特征与临床症状家畜螨病呈世界性分布,在我国各地均有报道。疥螨、痒螨和足螨可危害的动物种类存在一些差异,疥螨主要危害牛（黄牛、牦牛和水牛）、羊（绵羊和山羊）、猪、兔和马;绵羊痒螨主要危害牛（黄牛、牦牛和水牛）、羊（绵羊和山羊）、兔和马,牛足螨和德州足螨主要危害牛（黄牛、奶牛、牦牛和水牛）、羊（绵羊和山羊）和马。 相似文献
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van den Broek AH Huntley JF Mackellar A Machell J Taylor MA Miller HR 《Veterinary immunology and immunopathology》2005,105(1-2):141-150
Earlier studies of cattle and sheep have demonstrated that Psoroptes ovis infestations provoke an intense immunoinflammatory response dominated by eosinophils accompanied by a substantial infiltrate of lymphocytes. However, the kinetics of the lymphocyte response and the subtypes involved have not been characterised. We employed two groups of sheep to investigate the early (1-21 days) and later (21-63 days) infiltration of lymphocyte subpopulations and dendritic cells in primary infestations of sheep with P. ovis. Immunohistochemistry indicated that by 4 days after infestation numbers of CD4+ and CD45RA+ cells in lesional skin had increased significantly (P<0.03 and P<0.005, respectively) and that a significant increase in gammadelta T cells and dendritic cells (CD1b+) had occurred by 8 days (P<0.02 and P<0.01, respectively). Numbers of lymphocyte and dendritic cells declined from 49 to 63 days after infestation. Our observations suggest that mite-derived products exert a profound influence on the early recruitment of lymphocytes that may significantly influence the genesis of the adaptive immune response. 相似文献
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Diagnosis of psoroptic sheep scab with an improved enzyme-linked immunosorbent assay 总被引：1，自引：0，他引：1
An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of specific antibodies against crude Psoroptes antigen. The diagnostic sensitivity was 93.7% in 191 sheep with clinical signs associated with mange. These animals originated from 29 flocks in which psoroptic mites were detected. All of 59 sheep infested with Psoroptes ovis were seropositive. Additionally, in 49% of 70 clinically unaffected sheep originating from P. ovis-infested flocks, specific antibodies could be detected, suggesting that asymptomatic infestations can be diagnosed by serology. The specificity of the ELISA was 96.5% as determined with 254 sheep originating from 44 flocks without clinical mange. Cross-reactivity in a low range was detected with selected sera of sheep with clinical chorioptic or forage mite infestations. Four sheep seroconverted 2 weeks after experimental P. ovis infestation, i.e. 2 weeks before clinical signs became obvious. After successful doramectin treatment of 14 sheep with naturally acquired P. ovis infestation, the ELISA values declined slowly but remained positive in seven cases beyond 17 weeks. 相似文献
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A B Forbes S R Pitt D G Baggott S Rehbein D Barth A A Bridi L A Carvalho D J O'Brien 《Veterinary parasitology》1999,83(3-4):319-326
The options for the treatment and control of sheep scab (psoroptic mange) have been increased in recent years through the introduction of the endectocides ivermectin, doramectin and moxidectin. Whilst therapeutic efficacy is good, the current injectable formulations offer limited protection against re-infestation with Psoroptes ovis. An intraruminal controlled-release formulation of ivermectin has been developed to provide therapeutic and prophylactic activity against a range of sensitive endo- and ecto-parasites of sheep for 100 days after administration. These ivermectin boluses are designed to release ivermectin at 20-40 microg/kg/day over 100 days and were developed for use in sheep of 20-90 kg bodyweight. Several controlled therapeutic and prophylactic trials against sheep scab have been conducted under a variety of protocols with such boluses in Europe and South America. The results of these studies indicate that the bolus provides 100% therapeutic efficacy against established P. ovis infestations and equivalent prophylactic efficacy against challenge infestations administered during the active life of the bolus. 相似文献
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The astigmatid mite Psoroptes ovis is the causative agent of sheep scab, a highly contagious parasitic disease of sheep. Infection causes severe allergic dermatitis, resulting in damage to the fleece and hide, loss of condition and occasional mortality. Interest in the P. ovis allergens led us to characterise a glutathione S-transferase (GST) which displays homology to GST allergens isolated from the house dust mite, Dermatophagoides pteronyssinus and the cockroach, Blatella germanica. A cDNA encoding a mu-class GST from P. ovis was expressed in Escherichia coli and the recombinant protein purified for biochemical analysis. SDS-PAGE analysis indicated that the purified product was homogeneous and had an apparent molecular weight of 30 kDa. The recombinant GST (rGST) is active towards the substrate 1-chloro-2,4-dinitrobenzene (CDNB), whereas 1,2-dichloro-4-nitrobenzene (DCNB) is a poor substrate. The recombinant protein was also tested for recognition by IgE and IgG antibodies in serum from P. ovis na?ve and P. ovis infested sheep. Neither IgE nor IgG antibodies were detected to the rGST. Prausnitz--Küstner testing with rGST did not provoke a characteristic weal and flare response. Biopsies collected at the PK test sites were stained for eosinophils, neutrophils, mast cells and basophils. Neutrophil, mast cell and basophil counts were not significantly different to the controls. Eosinophil numbers were significantly higher than controls, but were not due to an IgE response. 相似文献
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Cows were infected twice with 600 and 500 nymphs and adults of a bovine strain of Psoroptes ovis with a nine-week interval. The haematological response and the non-specific mitogen- and antigen-induced responsiveness of the peripheral blood lymphocytes of the animals was followed. Dermal reactivity to P ovis antigen injection was studied five weeks after reinfection. After the first infection with 600 mites none of the infected animals developed clinical psoroptic mange but a leucocytosis developed, contributed to primarily by an eosinophilia and by a slight lymphocytosis. Antigen-induced lymphocyte blastogenesis was used to measure the antigen-sensitive cell population in peripheral blood and this population showed a maximum increase 10 days after infection; however, antigen-sensitive cells remained above normal levels until reinfection. Upon challenge infection with 500 mites the infected animals showed an immediate hypersensitivity type reaction with a marked pruritus, scratching and exudation. Thereafter the lesions healed rapidly and none of the animals developed clinical mange. This clinical reaction was accompanied by a secondary eosinophilia but no change was apparent in the other blood elements. A marked increase in the blastogenic response of the peripheral blood lymphocytes was also apparent and this peaked three weeks after challenge. Following the intradermal injection of P ovis antigen there was an immediate swelling of the injection site in all infected and control animals and skin thickness was maximal one hour after injection. Thereafter there was a clear distinction in dermal reactions between P ovis infected and control animals; after 48 hours reactions were not seen in the control animals while marked dermal reactions were still present in the P ovis infected group. 相似文献
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王尚荣 《中国兽医寄生虫病》2007,15(2):19-21
目的为查明治疗杂交奶牛痒螨病的最佳药物。方法采用6种不同药物对杂交奶牛痒螨病予以治疗,分别在用药后的d 20、40、60、80观察其疗效。结果不同的药物对杂交奶牛的痒螨病均有一定的疗效,但随着时间的推移,痒螨病的复发率较高,80 d后观察,试Ⅰ组(克虫星组)疗效最好,痊愈率达60%,试Ⅵ组(农用柴油组)疗效最低,痊愈率只有20%。 相似文献
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The construction of a cDNA expression library for the sheep scab mite Psoroptes ovis. 总被引：9，自引：0，他引：9
The need for alternative control strategies for sheep scab is critical. One approach is to develop vaccines based on 'concealed' antigens derived from Psoroptes ovis. This strategy requires the identification and characterisation of potential target antigens, which has been hampered by the problem of limited biological material for isolation of protein antigens. To aid the discovery of P. ovis antigens and to provide a resource for generating recombinant protein, we constructed a P. ovis cDNA expression library, using total RNA isolated from 250 mg of mixed-stage P. ovis and the Clontech SMART cDNA synthesis kit. The presence of P. ovis-specific sequences was confirmed using PCR amplification and sequencing of actin. The sequences of cDNA inserts from six random clones included one with high homology to the Dermatophagoides pteronyssinus (house dust mite) antigen p Dp15. This is a glutathione S-transferase known to be an important house dust mite antigen. We conclude that this library will be a useful tool for the identification of potential target antigens for the immunological control of P. ovis and to further our understanding of the pathology of sheep scab. 相似文献
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The effects of temperature and humidity on the off-host survival of Psoroptes ovis and Psoroptes cuniculi. 总被引：2，自引：0，他引：2
The effects of both temperature and humidity on the survival of the mites Psoroptes ovis and Psoroptes cuniculi were considered in laboratory assays. When P. ovis and P. cuniculi were maintained at 95% humidity, maximum survival decreased linearly with increasing temperature, from approximately 15 days at 9 degrees C to 5 days at 30 degrees C. There was no significant difference between P. ovis and P. cuniculi in the effects of temperature on maximum survival. Adult male P. ovis and P. cuniculi had lower mean maximum survival than any of the other life cycle stages. There was a small but significant effect of humidity on survival for P. cuniculi; LT50 values were greater at 75-85% r.h. than at 55-65% r.h. The influence of off-host survival and the infestation of naive sheep from mites in the environment on the epidemiology of sheep scab are discussed. 相似文献
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Role of the spleen and rosette-formation response in experimental Eperythrozoon ovis infection 总被引：1，自引：0，他引：1
The role of the spleen and rosette-formation responses was investigated in sheep experimentally infected with Eperythrozoon ovis. Phagocytic activity was observed in the spleen 19 days after primary infection. Phagocytosis of E. ovis-parasitised and non-parasitised erythrocytes by cordal reticular cells occurred. E. ovis organisms seemed to be detached from the erythrocytes by pseudopodia extending from macrophages and cordal reticular cells without causing damage to the plasmalemma of the erythrocyte. No phagocytic activity was observed in spleens removed 74 and 146 days after infection. Antigen-specific lymphoid cell responsiveness, assessed by rosette formation, indicated that 2.8, 15.4, 8.0 and 6.0% of lymphoid cells in the spleens of the four E. ovis-infected sheep, respectively, formed antigen-specific rosettes. Rosette formation did not occur when splenic lymphocytes from E. ovis-infected sheep were mixed with non-infected erythrocytes or when splenic lymphocytes from an uninfected sheep were used. 相似文献
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Z Woldehiwet 《Research in veterinary science》1991,51(1):40-43
The lymphocyte subpopulations in the peripheral blood of normal sheep and sheep experimentally infected with Cytoecetes phagocytophila, the causative agent of tick-borne fever, were analysed by flow cytometry, using a panel of monoclonal antibodies against specific lymphocyte epitopes. Experimental infection with tick-borne fever was characterised by a significant reduction in the total number of circulating lymphocytes six days after experimental infection (P less than 0.001). This lymphocytopenia was associated with a significant reduction in the number of B (LCAp220+) and T (CD5+) lymphocytes (P less than 0.001) but there was a significant increase in the number of cells which were neither T nor B (CD5-LCAp220-) cells (P less than 0.01). The reduction in the number of T lymphocytes was due to reduced numbers of circulating CD4+ (helper) T cells, CD8+ (cytotoxic/suppressor) T cells and those with the pan T cell marker (CD5+) but without CD4 or CD8 epitopes (CD4-CD8-). All lymphocytes returned to preinoculation levels 13 to 16 days after experimental infection. 相似文献