农三师马传贫流行病学调查与防治

根据国家农业部马传染性贫血防治规划大纲和新疆生产建设兵团马传染性贫血防治规划的要求，新疆生产建设兵团在2011年-2015年马传染性贫血要达到稳定控制标准。农三师1987年首次确诊2例马传染性贫血，随后通过养、监、隔、封、消、处、灭等综合性防控措施，到1988年监测无阳性病例。疫情得到有效控制。2001年至今再未出现临床病例，也未检出阳性马属动物，马传贫得到有效控制和净化。     

玉溪市消灭马传染性贫血的做法及经验

为弄清马传贫在玉溪市的防制情况,经过玉溪市几代兽医工作者的辛苦工作,采取普查、检疫、隔离、扑杀等综合防控措施,取得了较好的防制成果。1993年10月,经云南省畜牧局考核验收达到马传贫"稳定控制标准";2016年10月全市达到部颁马传贫消灭标准,并通过了云南省农业厅的达标验收。     

普洱市马传染性贫血的血清学调查

为了解普洱市马传贫的流行情况,本文认真梳理了普洱市历年来马传贫血清学监测情况,发现:普洱市自1977年开始开展马传贫血清学监测,至今经历了普查、免疫防控、稳定控制、消灭、巩固五个阶段。自开展血清学调查以来,所采用的方法均为琼脂扩散试验,1977—2018年共监测37 259份样品,结果阳性336份,阳性率为0.9%。历史上检出阳性结果的年份仅为1978、1979、1988、1989、1990、1991、1997、1998年。1999年开始至2016年连续17年检测结果全为阴性,达到了农业部规定的消灭标准,并于2016年11月通过考核验收,据此可宣布普洱市已消灭马传贫。2017—2018年两年来普洱市继续开展了马传贫的巩固监测,结果也均为阴性。马传贫的血清学调查为普洱市消灭马传贫以及巩固消灭成果发挥了极为关键的作用。     

普洱市马传染性贫血流行病学研究

本文对普洱市自1977年以来开展的马传贫普查工作进行了回顾,详细介绍了普洱市历年来马传贫检疫、净化、免疫情况、流行病学概况及特点。根据调查情况分析得出通过采取监测检疫、扑杀淘汰、无害化处理、免疫注射、加强流通监管等综合防控措施,是马传贫防控最有效、最彻底的办法。普洱市自1999年开始至2016年检测结果全为阴性,从1997年停止注射疫苗至今已有20年。对照农业部标准,普洱市马传贫已达消灭标准,并于2016年11月通过考核验收。     

马传染性贫血的防治历史及消灭状态维持

马传染性贫血简称马传贫,是由马传贫病毒引起的马属动物的一种传染病,该病被世界动物卫生组织定为B类传染病,我国将其列入二类动物疫病。该病1843年在法国发现,随后流行至世界各地。1931年日本侵华时把此病带进我国东北、华北等地,后来由前苏联进口马匹时又将该病传入我国,造成该病疫情严重。1965年,解放军兽医大学首次分离到马传贫病毒,随后成功研制了马传贫补体结合反应和琼脂扩散反应两种特异诊断方法。1975年哈尔滨兽医研究所有成功研制了马传贫驴白细胞弱毒疫苗,该疫苗的推广应用,结合采取“养、检、隔、封、消、处”等综合性防控措施,是我国的疫情得到控制。按照《国家中长期动物疫病防治规划(2012-2020年)》要求,我国将于2020年达到消灭标准。     

昭通市马传染性贫血防控工作存在的问题及建议

马传染性贫血(Equine Infectious Anemia,EIA)简称马传贫,是由反转录病毒科慢病毒属马传贫病毒引起的马属动物传染病,被国际兽医局列为重点疫病之一,我国将其列为二类动物疫病。本文介绍了马传贫监测方法、防控工作中存在的问题、建议采取的防控措施。     

宿州市马传染性贫血的防治

马传染性贫血(简称马传贫)是由马传染性贫血病毒引起的一种严重危害马属动物的疫病，以马的易感性最强，骡、驴次之。该病20世纪60年代末至80年代初在我市多次发生和流行，严重地影响了我市畜牧业的发展。几十年来，我市按照农业部及省局要求，坚持“预防为主”的方针，采取严格检疫、监测、预防注射、扑杀病畜和阳性畜等综合性防制措施，到80年代中期，马传贫疫情得到控制，并于1995年通过农业部考核验收，达到稳定控制区标准。     

黑龙江省马传染性贫血病综合性防治技术的研究与应用

马传染性贫血病（以下简称马传贫）是由马传贫病毒引发的,严重危害马属动物健康的急性、亚急性和慢性致死性传染病。多年来,我省马传贫防治工作,科学地总结并落实了＂养、防、检、隔、封、消、处＂七字综合性防控措施,取得了显著的防治效果。     

天津市和黑龙江省达到马传贫消灭标准

根据《关于印发马传染性贫血等疫病防治规划及考核标准和验收方法的通知》文件的规定，农业部考核组分别于4月和7月对天津市和黑龙江省的马传贫防控工作进行了达标验收。经考核，天津市和黑龙江省有关市县政府和主管部门高度重视马传贫防控工作，防治措施有力，提供材料齐全、     

辽宁省消灭马传染性贫血关键技术研究

经农业部消灭马传染性贫血达标考核验收,辽宁省于2013年2月达到了消灭马传贫部颁标准。取得这一重大进展的创新性技术,关键在于科学地整合和配套应用马传贫琼脂免疫扩散检测技术、马传贫弱毒疫苗科学化免疫技术及马传贫强弱毒抗体鉴别诊断技术。探究和总结这一创新性技术成果,对于现阶段开展其他动物疫病的防控乃至净化,具有重要借鉴和指导意义。     

Anthelmintic resistance in nematodes of horses

Suppressive anthelmintic treatment strategies originally designed to control Strongylus vulgaris in horses were extremely successful in reducing morbidity and mortality from parasitic disease. Unfortunately, this strategy has inadvertently resulted in the selection of drug-resistant cyathostomes (Cyathostominea), which are now considered the principal parasitic pathogens of horses. Resistance in the cyathostomes to benzimidazole drugs is highly prevalent throughout the world, and resistance to pyrantel appears to be increasingly common. However, there are still no reports of ivermectin resistance in nematode parasites of horses despite 20 years of use. It is unknown why resistance to ivermectin has not yet emerged, but considering that ivermectin is the single most commonly used anthelmintic in horses most parasitologists agree that resistance is inevitable. The fecal egg count reduction test is considered the gold standard for clinical diagnosis of anthelmintic resistance in horses, but diagnosis is complicated by lack of an accepted standard for the performance of this test or for the analysis and interpretation of data. Presently there is very little data available on the molecular mechanisms of anthelmintic resistance in cyathostomes; beta-tubulin gene is the only anthelmintic-resistance associated gene that has been cloned. The increasingly high prevalence of anthelmintic-resistant cyathostomes must be taken into account when designing worm control programs for horses. Strategies to decelerate further selection for drug resistance thereby extending the lifetime of currently effective anthelmintics should be implemented whenever possible. Considering the nature of the equine industry in which horses often graze shared pastures with horses from diverse locations, transmission and widespread dispersal of resistant parasites is virtually assured. A proactive approach to this problem centered on understanding the molecular basis of anthelmintic resistance in cyathostomes is required if we are to expect chemical control of nematodes in horses to remain a viable element of parasite control in the future.     

安徽省马鼻疽防制

安徽省１９５３年由于阜阳地区自外省购入马匹而带入马鼻疽，５０－８０年代该病在淮北及沿淮局部地区流行，疫情发生后，由于各地积极采取检疫、扑杀、隔离、消毒等综合必防治措施，１９９０年后临床再无病例发生,检疫中也再未检出阳性畜。１９９６－１９９８年连续３年在原疫区以鼻疽菌素点眼检疫马属动物７７００５匹，结果均为阴性，１９９９年１１月底农业部专家组验收，达到消灭标准。     

Clinical signs and etiology of adverse reactions to procaine benzylpenicillin and sodium/potassium benzylpenicillin in horses

Case reports of 59 horses reacting adversely to procaine benzylpenicillin or to sodium or potassium benzylpenicillin in Sweden in 2003-2005 were obtained through contacts with horse-owners. For the assessment of the reports, various parameters were evaluated, such as the times to the reactions, information on previous penicillin treatment, the clinical signs and the actions taken in the reacting horses. Among the reports, two horses had received sodium or potassium benzylpenicillin intravenously, whereas the remaining 57 horses had been treated with procaine benzylpenicillin intramuscularly. Allergy may underlie the adverse reactions in the horses given sodium and potassium benzylpenicillin, and in a few of the horses given procaine benzylpenicillin. However, in most horses in the latter group, the clinical signs may be due to the toxic effects of procaine. In these horses, the dominating clinical signs were locomotor and behavioral changes. Some risk factors may enhance the probability that horses react to procaine. One is repeated injections, which increase the likelihood of intravascular administration and also may increase the sensitivity to procaine due to neuronal sensitization (kindling). Procaine is rapidly hydrolyzed by plasma esterases to nontoxic metabolites. When high amounts of procaine enter the circulation, the hydrolyzing capacity may be exceeded and toxicity occurs. Analyses of plasma esterases from reacting horses showed lower activity than in nonreacting control horses. Low esterase activity may increase the possibility of procaine toxicity and constitute another risk factor.     

Are feeding practices associated with duodenitis-proximal jejunitis?

REASONS FOR PERFORMING STUDY: Feeding concentrate has been putatively associated with risk of development of duodenitis-proximal jejunitis (DPJ); however, this association has not been evaluated systematically in a controlled study. OBJECTIVES: To determine whether there was evidence that feeding practices were associated with increased odds of developing DPJ employing a case control study. HYPOTHESIS: The amount of concentrate fed daily to horses is significantly greater among horses that develop DPJ than control horses with either lameness or other types of colic. METHODS: Feeding practices of cases of DPJ diagnosed between 1997 and 2003 were compared with those of 2 populations of control horses (colic controls and lameness controls) admitted to the clinic from the same time period. Following multiple imputation of missing data, comparisons were made using polytomous logistic regression. RESULTS: Horses with DPJ were fed significantly more concentrate and were significantly more likely to have grazed pasture than either control populations; DPJ horses were significantly more likely to be female than were lameness horses. Results were unchanged after adjusting for bodyweight of the horse. CONCLUSIONS: Feeding and grazing practices differ among horses with DPJ relative to horses with other forms of colic and lame horses. POTENTIAL RELEVANCE: The observed magnitudes of association were not sufficiently strong to merit diagnostic/predictive application; however, these observations, if substantiated by other studies, might provide important aetiological clues.     

Rapid, multiwell colorimetric assay for measuring neutrophil chemoattractant activity in bronchoalveolar lavage fluid of horses with recurrent airway obstruction.

The criteria used to diagnose recurrent airway obstruction (RAO) in affected horses include demonstration of reversible lower airway obstruction and greater than 25% neutrophils in bronchoalveolar lavage fluid (BALF). Additional objective laboratory tests are needed to improve diagnostic accuracy and to monitor response to treatment. The goal of this study was to determine if neutrophil chemoattractant activity of BALF could be measured by using a previously described, rapid, multiwell colorimetric assay for chemotaxis. In this assay, neutrophils that have migrated through a membrane filter are collected into the bottom well of a disposable chemotaxis-cell migration chamber. The number of viable cells collected in the bottom well is quantified by measurement of the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenol tetrazolium bromide (MTT), which is reduced by dehydrogenase in mitochondria of live cells. The number of migrating cells corresponds to the amount of MTT reduced, which is measured with an enzyme-linked immunosorbent assay plate reader. Fourteen adult horses were enrolled in this study, 7 of which had owner histories consistent with RAO. Each horse was sedated, a bronchoalveolar lavage tube was passed, and saline was infused and immediately aspirated. An aliquot of BALF was used for differential cell count, and BALF supernatant was harvested to assess neutrophil chemoattractant activity. Normal control horses and RAO-affected horses were distinguished according to clinical signs and percent neutrophils in BALF. Neutrophil chemoattractant activity of BALF was significantly greater in RAO-affected horses (P = 0.001) compared with control horses. This assay may be useful in future studies for monitoring response to therapy in RAOaffected horses.     

Review of the epidemiology and infection control aspects of nosocomial Salmonella infections in hospitalised horses

Outbreaks of nosocomial Salmonella infections in hospitalised horses can occur when surveillance and infection control protocols are not in place, or not well structured and enforced. The aim of this article is to present a review of published studies that have contributed to the literature of the epidemiology and infection control aspects of nosocomial Salmonella infections in hospitalised horses. The review highlights important elements that must be taken into consideration during the formulation, implementation and evaluation of a hospital surveillance and infection control programme designed to reduce the risk of an outbreak of nosocomial Salmonella infection in hospitalised horses.     

Response to nasopharyngeal oxygen administration in horses with lung disease

REASONS FOR PERFORMING STUDY: Guidelines for administration of oxygen to standing horses are unavailable because previous investigations of the efficacy of oxygen administration to increase arterial oxygenation in standing horses have produced equivocal results. OBJECTIVE: To determine the effect of nasal oxygen supplementation on inspired and arterial blood gas tensions in control horses and those with moderate to severe recurrent airway obstruction (RAO). METHODS: Normal horses (n = 6) and horses during an attack of RAO induced by stabling (n = 6) were studied. Oxygen was administered through either one or 2 cannulae, passed via the nares into the nasopharynx to the level of the medial canthus of each eye. Intratracheal inspired oxygen and carbon dioxide concentration and arterial blood gas tensions were measured at baseline and during delivery of 5, 10, 15, 20 and 30 l/min oxygen. RESULTS: Nasal cannulae and all but the highest oxygen flow rates were well tolerated. Fractional inspired oxygen concentration (F(I)O2) increased with flow but was significantly lower at all flow rates in horses with RAO compared with controls. Arterial oxygen tension (PaO2) was significantly increased (P < 0.001) by all flow rates, but was always lower in RAO-affected animals. At 30 l/min, PaO2 increased to 319 +/- 31 mmHg in control horses and 264 +/- 69 mmHg in horses with RAO. Additionally, a large arterial to end-tidal gradient for CO2 in RAO-affected horses was observed, indicating increased alveolar deadspace ventilation in these animals. CONCLUSIONS: The use of nasal cannulae to deliver oxygen effectively increases both F(I)O2 and PaO2 in horses with moderate to severe RAO. Oxygen flow rates up to 20 l/min are well tolerated, but flow rates of 30 l/min produce occasional coughing or gagging. POTENTIAL RELEVANCE: Oxygen therapy delivered by means of an intranasal cannula is a highly effective means of increasing arterial oxygen tension in horses with respiratory disease. Generally, flows of 10-20 l/min should be effective. If higher flows (20-30 l/min) are necessary, they should be delivered by means of 2 cannulae.     

Influence of foreign stallions on the Swedish Warmblood breed and its genetic evaluation

The objective of this study was threefold: 1) To survey the use and impact of foreign stallions in the Swedish Warmblood (SWB) breed 2) To investigate the impact of including genetic groups in the genetic evaluation of the SWB and 3) To estimate the impact of incomplete pedigree information on the estimated breeding values (EBVs) for stallions. Data consisted of 189,330 horses of which 50,907 had performance information. Studbook of origin was determined for stallions with at least 5 progeny tested in Sweden. Those 757 stallions had together 116,505 progeny registered in the SWB. Genetic groups were formed according to preliminary analyses of the genetic levels in dressage and show jumping of the different populations. During the first studied period, comprising horses born before 1980, about 80% of the foals were sired by Swedish born stallions, whereas these only sired 40% of the horses born 1990–2003. In this period Holstein stallions had sired 21% of the foals and Dutch stallions (KWPN) 10%. The proportion of mares covered by foreign stallions increased after the early 1980s to about 80% in 2006. Some of the foreign populations, e.g., Holstein, Selle Francais and KWPN, have significantly affected the show jumping performance level of the SWB breed in the past although the deviation from SWB stallions has become smaller over time. Regarding dressage, no particular foreign population has consistently shown such an impact on the performance although Oldenburg stallions seem to be influential lately. The pedigree completeness (PEC values) of the horses included amounted on average to 0.845 for horses with performance data and to 0.907 for stallions with at least 15 progeny. Foreign stallions had an average PEC value of 0.858. When simulating no pedigree information available for foreign stallions, the EBVs of these stallions changed on average by 19–22 index units, which equals about one genetic standard deviation. Thus, keeping complete and correct pedigree registers is crucial for the assessment of reliable EBVs of SWB horses. Including genetic groups in the genetic evaluation of the SWB resulted in hardly any re-ranking of horses. Correlations between EBVs were about 0.99. Inclusion of genetic groups caused larger standard errors of the EBVs. Furthermore, as the pedigrees on average have great depth, and partially also because Warmblood sport horses have become a mix of many different populations, it was not recommended to include genetic groups in the model for future routine genetic evaluations of SWB.     

Nonsteroidal anti-inflammatory agents and musculoskeletal injuries in Thoroughbred racehorses in Kentucky

Injuries sustained by horses during racing have been considered as an unavoidable part of horse racing. Many factors may be associated with the musculoskeletal injuries of Thoroughbred race horses. This study surveyed the amounts of nonsteroidal anti-inflammatory agents (NSAIDs) in injured horse's biological system (plasma) at Kentucky racetracks from January 1, 1995 through December 31, 1996. During that period, there were 84 catastrophic cases (euthanized horses) and 126 noncatastrophic cases. Plasma concentrations of NSAIDs were determined by High Performance Liquid Chromatography in injured and control horses. The possible role of anti-inflammatory agents in musculoskeletal injuries of Thoroughbred race horses was investigated by comparing the apparent concentrations of NSAIDs in injured horses to concentrations in control horses. The plasma concentrations of phenylbutazone and flunixin were higher in injured horses than in control horses. Most injured and control horses did not have a detectable level of naproxen in their plasma samples. Further studies must be carried out to determine whether horses with higher plasma concentrations of NSAIDs have an altered risk of musculoskeletal injuries compared with other horses.     

Control of equine piroplasmosis in Brazil.

The importance of equine piroplasmosis control in endemic countries has increased in recent years and plays an important role to maintain the international market open to the horse industry. The purpose of this study was to demonstrate the occurrence of equine piroplasmosis (Babesia equi or Theileria equi and Babesia caballi) in Brazil--a country where the disease occurs endemically--in different climatic conditions, and to evaluate the results of a strategy for tick control in order to decrease infection rates. Blood samples were taken from 720 horses on 28 farms from different regions and subjected for complement fixation testing. The strategy was based on the control of the tick population by spraying the horses with acaricides, treating positive horses and preventing cattle and horses from grazing together. A significant association was found in the prevalence of antibody titres in tropical and subtropical areas. A significantly lower prevalence rate occurred on those farms where measures to control tick population were established. Farms in endemic countries may significantly reduce the prevalence of equine piroplasmosis by establishing measures to control the tick population and treating chronic carrier horses. Additional measures for controlling ticks in tropical areas are also discussed.