The Use of Far Infrared Treatment Prior to Exercise in Horses: An mfBIA and Acoustic Myography Three Case Study

Background: Acute effects of Far Infrared (FIR) treatment in horses are unknown, especially short periods of 30 minutes, as is any effect on such muscle parameters as warm-up balance, overall exercise balance and laterality asymmetries. Aim: This study examines three equine cases in detail to measure any effects of a short period of FIR treatment. Methods: Multi-frequency bioimpedance (mfBIA) and acoustic myography (AMG), non-invasive techniques, were applied pre- and post-treatment with FIR to the back (T5-L4/5) and for m.Longissimus dorsi and m.Gluteus medius was recorded during a 15-minute warm-up regimen. mfBIA parameters included extracellular resistance (Re), centre frequency (fc), membrane capacitance (Mc), intracellular resistance (Ri) and phase angle (PA) which indicates level of training and health status. Results: FIR treatment responses for mfBIA parameters were found to be horse-specific and different, whilst in terms of AMG, FIR treatment for 30 minutes had a beneficial effect on overall balance in all three horses (5 out of 6 muscles), and a beneficial effect on the AMG parameter ST (force symmetry) in all three horses (6 out of 6 muscles). An overall improvement for combined balance and ST values for both muscles and all three horses of 86% was noted with FIR treatment, compared to 56% without. Conclusions: This preliminary study of FIR treatment in three horses, has been found to result in an overall improvement in combined balance and ST values for both muscles. FIR has potential as a promising treatment to reduce the risk of warm-up-related injuries in athletic horses.

Association between Infrared Thermography, Blood Count and Creatine Kinase in the Evaluation of the Welfare of Vaquejada Horses

The Quarter-Horses regularly participate in non-traditional sports that simulate activities on cattle ranches. In the vaquejada races, the horses run at about 30 km/h, reaching maximum heart rates of around 200 bpm, indicating the great physical effort during competitions and with that could impact welfare. To test the hypothesis that vaquejada horses can be evaluated for the quality of welfare through a combination of non-invasive and invasive methods, an experiment was developed that aimed to assess the quality of welfare through thermography and blood biomarkers before and after vaquejada races. Ten vaquejada horses, which were in regular competition, were submitted to the vaquejadas racing test were used. Thermography was performed in 14 regions of interest (head, neck and thorax) in the following phases: pre-race and +1, +4 and +24 hours of the races. Blood samples were collected in pre-race, immediately after and +1, +4 and +24 hours of the races. Results were submitted to ANOVA and Tukey’s test, with p set at 5%. Thermography showed that local temperatures before the race and +24 hours after the races were similar (p > 0.05), as well as between +1 and +4 hours after the races (p > 0.05), which showed higher surface temperatures than the first group (pre-race and +24 hours) (p 0.05) after the exercises. In conclusion, the vaquejada horses evaluated by infrared thermography and blood analyses maintained the quality of well-being, with the physiological elevation of several parameters after the races and recovery in less than 24 hours after the races. Thermographic images were also able to help in the analysis of the regions of interest that have contact with harnesses, demonstrating that the use of adequate and correct equipment does not compromise animal welfare.

Double Arthrodesis, Postero-Medial Release and Posterior Tibial Transfer in One Step in Paralytic Inveterate Equine Varus Foot

Introduction: Varus equine foot deformity is common in developing countries. The management of these deformities is surgical in adults. Several surgical techniques have been described with more or less satisfactory results. To our knowledge, no study has been performed on the simultaneous association of double arthrodesis, posteromedial release, and posterior tibial transfer in a single operation in inveterate paralytic varus equines feet. The purpose of this work was to evaluate the results obtained. Patients and Method: This was a retrospective descriptive study from January 01, 2018 to December 31, 2021. It concerned inveterate paralytic varus equines feet operated on by the simultaneous association in a single operative time of double arthrodesis of the foot, posteromedial release of the back foot and transfer of the posterior tibial muscle to the lateral cuneiform. We identified seven patients with a mean age of 22.1 years with extremes of 11 years and 36 years. There were three males and four females. The cause of the deformity was neurological in all cases. All patients had painful walking discomfort and shoeing difficulties. The average time to management was 13.3 years with extremes of 4 and 25 years. The chronology of the interventional steps was posteromedial release, arthrodesis, and transfer of the posterior tibial muscle to the lateral cuneiform. The average postoperative follow-up was 21.7 months with extremes of 6 and 48 months. The parameters studied were the duration of the procedure, complications related to the procedure, muscle strength at the last recoil, consolidation of the arthrodesis, residual pain, patient activity, gait perimeter, stepping, ankle mobility, residual deformity, footwear, protrusion of the transferred tendon, and the possibility of walking on the heel. Final results were graded according to the Angus and Cowell criteria. Results: No intraoperative complications were noted. An early superficial infection of the surgical site was noted. It was treated with local care and healed without sequel. Residual pain was present in one case. Tibiotalar osteoarthritis was observed in one case, which required a tibiotalar arthrodesis. At the last follow-up, consolidation of the arthrodesis was effective in all patients. The posterior tibial muscle was side 5 (n = 4) and 4 (n = 3). The patients’ activity was normal without assistance in all cases. The walking perimeter was greater than 1 km in six patients. Patient activity was normal without assistance in all cases. Stepping was absent in all patients. No difficulty with footwear was noted. According to the Angus and Cowell criteria, the result was good (n = 6), i.e. 85.7% and bad (n = 1), i.e. 14.3% of cases. Conclusion: This study suggests that double arthrodesis associated with posteromedial release and transfer of the posterior tibial in one step in inveterate paralytic varus equines feet, gives satisfactory results. It allows for easy shoeing and plantigrade walking without stepping. Complications are essentially represented by the absence of fusion of the arthrodesis and tibiotalar arthrosis.

马流感病毒(A/equine/Qinghai/1/94)核蛋白基因的序列测定及同源性分析

根据已发表的马流感病毒核蛋白基因序列 ,设计并合成一对特异性引物 ,经反转录_聚合酶链反应 (RT_PCR)成功扩增出了我国马流感病毒 (A/Equine/Qinghai/ 1/ 94 )核蛋白基因 ,将该片段连接到PGEM_T_EASY载体并转化DH5α ,提取阳性菌落的质粒经EcRo1酶切和PCR鉴定其大小为 1.5kb左右 ,对其测序并进行分析发现 ,与A/Equine /Kentucky/2 / 86、A/Equine/Miami/ 1/ 6 3等关系较近 ,同源率为 93.3%～_97.4 % ,而与我国马流感吉林A/Equine/Jilin/ 1/ 89株关系较远 ,同源率仅为 84 .6 %。

利用流式细胞术测定CTL活性方法在EIAV免疫学中的应用

利用PKH-26和CFSE两种荧光染料对靶细胞染色,建立了一种通过流式细胞术进行马传染性贫血症病毒 (Equine infectious anemia virus,EIAV)抗原特异性细胞毒性T淋巴细胞(Cytotoxic T lymphocytes,CTL)反应的 新方法,避免了经典的Cr51释放法对检测人员的放射线威胁,降低了本底释放,提高了检测的灵敏度。将该检测方 法用于检测EIAV疫苗毒接种马和嵌合克隆接种马的细胞免疫反应变化趋势,数据显示细胞免疫反应在接种后3 个月达到成熟阶段而后保持在较高的反应水平。该方法的成功建立和应用为研究EIAV减毒疫苗的免疫机制提 供了好的研究手段,也为其他病毒的免疫学研究提供了新的参考方法。

Environmental and biological factors affecting the abundance of Prosopis flexuosa saplings in the central-west Monte of Argentina

Background:Trees and forests in drylands help mitigate the challenges through provision of economic products and vital environmental services such as habitat for biodiversity,prevention of erosion and desertification,regulation of water,microclimate,and soil fertility.The condition and changes in dry forests can be assessed by using ecological indicators able to quantify spatial and temporal changes in vegetation.One of the ways to determine the condition of the forest is to study the dominant tree species and its regeneration.Our study aimed to assess whether the abundance of Prosopis flexuosa saplings is affected by environmental and biological factors.Results:To evaluate the first variables we used data from remote sensing such as satellite images and Aster Global Digital Model(GDEM).The second set of variables was about exotic and native ungulates and we used feces of these animals and camera traps to take data.We found that sapling abundance related positively to sandy substrates and negatively to Wetness Index.On the other hand,in relation to biological variables,the abundance of saplings was positively affected by density of adult trees and by number of seeds dispersed by equines,but space use by Lama guanicoe had a negative relationship with saplings.This research shows that P.flexuosa saplings are benefited from sandy substrates and the conditions around adult trees.In addition to this,we found that exotic ungulates in low densities have neutral(i.e.cattle)or positive(i.e.equines)effects on sapling abundance.Conclusions:Based on these findings,we conclude that regeneration of the population of P.flexuosa in our study area has no major problems.In addition,we corroborated that the presence of exotic and domestic ungulates in low densities does not have deleterious consequences for saplings of the dominant tree,P.flexuosa.

Epidemiological Study on Equine Gastrointestinal Helminth Parasites in Mekelle, North Ethiopia

A cross-sectional examination of 384 fecal samples was conducted from July 2016 up to November 2016 to determine the prevalence of gastrointestinal helminth infections of equines in Mekelle, North Ethiopia. Out of total fecal samples examined 196 fecal samples were taken from horses, 164 from Donkeys and the rest 24 from Mules. The prevalence of gastro intestinal helminths was 41.6% as detected by coprological examination. Coprological examination revealed that the prevalence in horses was 33.7%, in donkeys 51.8% and in mules 37.5%. There is significant difference (p < 0.05) in the prevalence of GIT helminth infection between the equine species. Coprological examination revealed 35.4% infection with strongyle followed by mixed infections (10.4%), P. eqourum (8.3%), O. equi (5.7%) and Anoplocephala species (4%). No significant difference (p > 0.05) in prevalence of GIT helminth was noticed between sexes. However, a significant difference (p < 0.05) was noticed between the age groups, between different body conditions, feeding status, history of colic and frequency of deworming. The study revealed that Equines in the study area are infected with a range of heminths, which are representatives of the important equine pathogenic parasites found in Ethiopia.

Pathophysiology, diagnosis and treatment of intermittent claudication in patients with lumbar canal stenosis

Spinal nerve roots have a peculiar structure, different from the arrangements in the peripheral nerve. The nerve roots are devoid of lymphatic vessels but are immersed in the cerebrospinal fluid(CSF) within the subarachnoid space. The blood supply of nerve roots depends on the blood flow from both and peripheral direction(ascending) and the spinal cord direction(descending). There is no hypovascular region in the nerve root, although there exists a so-called water-shed of the bloodstream in the radicular artery itself. Increased mechanical compression promotes the disturbance of CSF flow, circulatory disturbance starting from the venous congestion and intraradicular edema formation resulting from the breakdown of the blood-nerve barrier. Although this edema may diffuse into CSF when the subarachnoid space is preserved, the endoneurial fluid pressure may increase when the area is closed by increased compression. On the other hand, the nerve root tissue has already degenerated under the compression and the numerous macrophages releasing various chemical mediators, aggravating radicular symptomsthat appear in the area of Wallerian degeneration. Prostaglandin E1(PGE1) is a potent vasodilator as well as an inhibitor of platelet aggregation and has therefore attracted interest as a therapeutic drug for lumbar canal stenosis. However, investigations in the clinical setting have shown that PGE1 is effective in some patients but not in others, although the reason for this is unclear.

Culture conditions for equine bone marrow mesenchymal stem cells and expression of key transcription factors during their differentiation into osteoblasts

Background： The use of equine bone marrow mesenchymal stem cells （BMSC） is a novel method to improve fracture healing in horses. However, additional research is needed to identify optimal culture conditions and to determine the mechanisms involved in regulating BMSC differentiation into osteoblasts. The objectives of the experiments were to determine： 1） if autologous or commercial serum is better for proliferation and differentiation of equine BMSC into osteoblasts, and 2） the expression of key transcription factors during the differentiation of equine BMSC into osteoblasts. Equine BMSC were isolated from the sterna of 3 horses, treated with purchased fetal bovine serum （FBS） or autologous horse serum （HS）, and cell proliferation determined. To induce osteoblast differentiation, cells were incubated with L-ascorbic acid-2-phosphate and glycerol-2-phosphate in the presence or absence of human bone morphogenetic protein2 （BMP2）, dexamethasone （DEX）, or combination of the two. Alkaline phosphatase （ALP） activity, a marker of osteoblast differentiation, was determined by ELISA. Total RNA was isolated from differentiating BMSC between d 0 to 18 to determine expression of runt-reloted tronscrJption foctor2 （Runx2）, osterix （Osx）, and T-box3 （Tbx3）. Data were analyzed by ANOVA. Results： Relative to control, FBS and HS increased cell number （133 ± 5 and 116 ± 5%, respectively; P 〈 0.001） and 5-bromo- 2＇-deoxyuridine （BrdU） incorporation （167 ± 6 and 120 ± 6%, respectively; P 〈 0.001）. Treatment with DEX increased ALP activity compared with control （1,638 ± 38%; P 〈 0.001）. In the absence and presence of Dex, BMP-2 did not alter ALP activity （P 〉 0.8）. Runt-reloted transcription foctor2 expression increased 3-fold （P 〈 0.001） by d 6 of culture. Osterix expression increased 94old （P 〈 0.05） by d 18 of culture. Expression of Tbx3 increased 1.8-fold at d 3 （P 〈 0.01）; however expression was reduced 4-fold at d 18 （P 〈 0.01）. Conclusions： Dexamethasone, but not BMP-2, is required for differentiation of equine BMSC into osteoblasts. In addition, expression of Runx2 and osterix increased and expression of Tbx3 is reduced during differentiation.

A Review: Interactions of Equine Herpesvirus-1 with Immune System and Equine Lymphocyte

Equine herpesvirus-1 (EHV-1) remains one of the most common viral pathogens affecting horses worldwide presenting as a persistent infection which can establish latency in nerve ganglia (trigeminal ganglion), lymphoid tissues of the respiratory tract and peripheral blood lymphocytes. EHV-1 infection induces both humoral and cellular immune responses in horses. Virus neutralising antibody, particularly in the nasopharynx, is to kill free virus shed from infected epithelial cells. Hence this antibody has important functions in reducing virus shedding and spreading infection to cohorts. Cellular immune responses, particularly those carried out by cytotoxic T lymphocyte (CTL), have been shown to be effective in killing virus-infected cells in vitro. This review underlines the state of knowledge regarding immunity to EHV-1 and also its interaction with equine lymphocyte. Finally, the review also includes the importance of the viral immediate early (IE) protein in the pathogenesis of EHV-1. This information can be used as the basis for future research.

Fast and Sensitive Chiral Analysis of Amphetamines and Cathinones in Equine Urine and Plasma Using Liquid Chromatography Tandem Mass Spectrometry

A simple, rapid, sensitive and reproducible method for enantiomer analysis of methamphetamine, amphetamine, cathinone and methcathinone was developed and validated. The compounds were extracted from equine plasma and urine using a fast liquid-liquid extraction procedure. Only one milliliter plasma and one hundred microliter urine sample is needed for analysis. The extraction procedure had good recovery (>70%) and the matrix effect was negligible. Enantiomer differentiation and confirmation were achieved using liquid chromatography with chiral stationary phase and mass spectrometry detection. The method demonstrated excellent reproducibility with intra-day and inter-day precision of lower than 5%. The lower limits of detection for all of the compounds studied here were at low pg/mL level for both plasma and urine. This is the first report of the analysis of four chiral compounds in equine plasma and urine. Routine application was demonstrated for (S)- and (R)-enantiomer differentiation.

Pattern of Development in Foals from Four Different Breeds between Birth and Weaning

Several studies have shown a major development in height and cannon bone circumference in foals from birth to weaning and from different breeds. However, in Brazil, there is little information about foal development. For this reason, this study has used data on foals from seven different farms in Pernambuco, Northeast Brazil, where horses have a major economic importance. The aim of this study was to compare foal’s development from four breeds and to develop a regression formula in order to estimate such development. It was used data from 210 suckling foals (Arabians n = 18, Campolina n = 86, Mangalarga Marchador n = 42 and Quarter Horses n = 64), raised in similar management practices. Their height at withers, heart girth, and cannon bone girth were measured monthly from birth to weaning. Data we reanalyzed by ANOVA and Tukey Test, with P established in 5%. The highest mean of height at withers was observed in the Arabian foals, and it was similar to Campolina and Mangalarga Marchador foals. The last breed presented a higher percentage of gain in height (~36%) and higher heart girth. On the other hand, Campolina foals had the highest mean of cannon bone girth. There was a significant interaction between breed and development phase in heart and cannon bone girths. All regression for mulas obtained from this data was very significant, and it was showed that they can predict height at withers in the four breeds studied. Heart and cannon bone girths showed medium value of R2 and large significance. It is important to highlight that fetal programing produces significant impact on foal development, even after weaning. So, this study would have observed some more changes if its scope had been extended beyond this phase.

Evolutionary Patterns of the Proviral gp90 V3 to V5 Regions of Equine Infectious Anemia Virus Associated with Immune Selection in Progressors and Nonprogressors

The aim of this study was to determine the genomic evolutionary pattern of virulent equine infectious anemia virus （EIAV） during persistent infection. The evolutionary dynamics of proviral genomes were examined by challenging an EIAV seronegative equine （pony 1） and three EIAV vaccinated equines （ponies 4, 7, and 8） with the Chinese virulent strain EIAV- L. Ponies 1 and 7 succumbed to disease and were called progressors, while ponies 4 and 8 lacked clinical symptoms and were considered nonprogressors. Sequences spanning the V3, V4, and V5 hyper-variable regions of the EIAV-L envelope gp90 gene were sequenced from each pony as evolutionary markers of the provirus. The proviral genome of the EIAV-L inoculum evolved during persistent infection and displayed different patterns between EIA progressors and nonprogressors. Inoculum-like variants were isolated from nonprogressors during persistent infection, but only from progressors during acute infection. Variant mutations from nonprogressors were dispersed throughout the sequenced region, while those from progressors were predominantly localized to V3. Humoral immunity and virus variant population selection analyses indicated that immune selection was positive in chronically infected progressors and weak in nonprogressors. In-frame stop codons were frequently localized to a defect ＂hot spot＂. The high number of defective variants in nonprogressors may promote disease survival.

Complete Sequence of Proviral DNA of Equine Infectious Anemia Virus Strain L

Equine infectious anemia virus strain L (EIAV-L) is the parental virulent virus of equine infectious anemia donkey leukocyte attenuated vaccine (DLA EIAV). In this study, peripheral blood leukocytes(PBL) were collected from a horse infected with EIAV-L.The PBL DNAs were extracted.The EIAV-L proviral DNA was amplified in four parts covering the entire proviral genomic sequence by polymerase chain reaction (PCR). Each of the four parts was cloned into the plasmid pBluescript SK, and the recombinant plasmids were designated as p2.8, p2.4. p3.1, and p1.2 respectively. After identification with restriction digestion, the inserts within the four plasmids were sequenced. The complete nucleotide sequence of EIAV-L provirus was determined by analyzing each of the four parts and connecting them as a whole. The genome of EIAV-L is 8235 bp in length, and G + C content is 38%. The comparison analysis by the computer software DNASIS showed that the sequence of EIAV-L shares 98.4% and 96.9% identities with that of D-A EIAV and DLA EIAV respectively. The high homology between these strains showed that they were genetically related. The homology between EIAV-L and D-A EIAV is higher than that between EIAV-L and DLA EIAV, and this is consistent with the derivation progress of DLA EIAV. At both ends of EIAV-L provirus, there is an identical long terminal repeat (LTR) sequence of 316bp in length. The LTR consists of U3, R, and U5 regions. The genome of EIAV-L provirus has three long open reading frames(ORF) corresponding to gag, pol and env genes respectively. The gag gene is 1200bp and located at position 613-1912nt. The pol gene is 3402bp and located at position 1708-5109nt. There is a termination codon within the env dividing it into two parts, envl of 699bp (position 5305-6003nt)and env2 of 1827bp (position 6073-7899nt). The provirus has three additional small ORFs: S1, S2 and S3 with sizes of 153bp(position 5113-5265nt), 204bp(position 5279-5482nt)and 402bp(position 7245-7646nt) respectively.

Changes of Biomarkers in Synovial Fluid in Equine OA Model

The pathogenesis of equine Osteoarthritis（OA） is more complex, and the disease in the early stage is not easy to be found, therefore, the early diagnosis and treatment are very important. Based on this, this experiment established OA model induced by equine, aimed to study the changes of contents of Matrix Metalloproteinases-3（MMP-3）, Matrix Metalloproteinases-13（MMP-13）, Aggrecanase（ADAMTS-5）, Hyaluronic Acid（HA） and Osteocalcin（OCN） in synovial fluid, and establish rapid diagnostic technique for the equine OA. Thirteen Mongolian equines were used in these induction studies. Equines were randomly divided into two groups： the experimental group contained eight equines and the control group contained five equines. The experimental group was to build the equine osteoarthritis model. The induction was done through Intra-articular（IA） injection of 2 m L Amphotericin-B in equines’ left carpal joints. The equine of the control group was injected into 2 m L physiological saline in equines’ left carpal joints. Synovial fluid was collected every week until the 9th week. The contents of MMP-3, MMP-13, ADAMTS-5, HA and OCN in synovial fluid were evaluated by using ELISA kits. Equine OA model, compared with the control group, starting from the 1st to the 2nd week after induction model, the content of MMP-3, MMP-13, ADAMTS-5, HA and OCN tended to increase, but there was no significant increase, from the 2nd to the 3rd week they significantly increased（p〈0.05） and kept increasing trend until the 9th week. In OA model, MMP-3, MMP-13, ADAMTS-5, HA and OCN showed a rising trend in joint fluid, which would accelerate the cartilage, subchondral bone degradation and metabolism of these proteases increased, and ADAMTS-5 and HA in the early stage increased significantly.

Immune Control of Equine Infectious Anemia Virus Infection by Cell-Mediated and Humoral Responses

Equine Infectious Anemia Virus (EIAV) is a retrovirus that establishes a persistent infection in horses and ponies. The virus is in the same lentivirus subgroup that includes human immunodeficiency virus (HIV). The similarities between these two viruses make the study of the immune response to EIAV relevant to research on HIV. We developed a mathematical model of within-host EIAV infection dynamics that contains both humoral and cell-mediated immune responses. Analysis of the model yields results on thresholds that would be necessary for a combined immune response to successfully control infection. Numerical simulations are presented to illustrate the results. These findings have the potential to lead to immunological control measures for lentiviral infection.

Selection of Reference Genes in Equine White Blood Cells for Real Time PCR Normalization Following Extracorporeal Shock Wave Therapy

Selection of proper reference genes (RGs) is an essential step needed for accurate normalization of results from genomic studies. Expression of RGs is regulated by many factors such as species, age, gender, type of tissue, the presence of disease, and the administration of therapeutic treatment. The aim of the present study was to identify optimal RGs in a set of blood samples collected at different time points (0, 24, 48, 72 h) from horses following administration of extracorporeal shock wave therapy (ESWT). The mRNA expression of twelve RGs: HPRT1, ACTB, HSP90A, SDHA, GUSB, B2M, UBC, NONO, TBP, H6PD, RPL32, GAPDH was determined using real time quantitative polymerase chain reaction (qPCR). An SAS program developed on the algorithm of geNorm, SASqPCR, was used to determine stability of the expression and the number of optimal RGs. The results showed that the range of quantification cycle (Cq) values of the evaluated genes varied between 17 and 26 cycles, and that one optimal RG, ACTB, was sufficient for normalization of gene expression. Results of stability of expression demonstrated that ACTB was the optimal choice for all the samples studied. Notably, in samples collected at 72 h post ESWT, TBP showed a significant change in the expression level, and was not suitable for use as a RG. These results substantiate the importance of validating and selecting an appropriate RG.

Risk Assessment and Comprehensive Control of Insect and Wild Animal Vectors in the Prevalence of Related Equine Diseases in the Specific Equine Disease-free Zone of Guangzhou Asian Games

[ Objective] In order to construct the specific equine disease-free zone of of the Guangzhou Asian Games, to ensure that the equestrian events of Guangzhou Asian Games be smoothly held. [Methods] The species, quantities, distribution and seasonal variations of insects and wild animals in related zones were investigated from 2008 to 2010, and the collected samples of the insects and wild animals were tested in laboratory for related equine diseases. [Results] The investigations indicated that there were some mosquitoes, flies, horseflies, punkies, ticks, bats, wild birds and wild bears in equastrianism venue and peripheral regions of disease-free zone of the Guangzhou Asian Games, the laboratory results of Japa- nese encephalitis, vesicular stomatitis, Nipah virus disease, West Nile fever, and Trypanosomiasis evansi, were all negative. According to the in- vestigations and test results, the risk assessments of insect and wild animal vectors in the prevalence of related equine diseases were made to con- firm that the risk was relatively low or very low, and comprehensive prevention and control measures with prevention as major measures and insecti- cides application and environment managements as supplementary means were made on the basis of the risk assessment conclusions. [ Conclu- sions] This research has laid a solid foundation for the successful building of the first specific equine disease-free zone in our country, ensured the smooth holding of the 16th equastdan competition in Guangzhou Asian Games.

Doping Control Analysis of 16 Non-Steroidal Anti-Inflammatory Drugs in Equine Plasma Using Liquid Chromatography-Tandem Mass Spectrometry

Non-steroidal anti-inflammatory drugs (NSAIDs) are classified as Class 4 agents by the Association of Racing Commissioners International and are banned in racehorses during competition in Pennsylvania (PA). To control the abuse of these agents in racehorses competing in PA, a forensic method for screening and confirmation of the presence of these agents is needed. Equine plasma (0.5 mL) was acidified with 75 μL 1M H3PO4 to increase recovery of the analytes by liquid-liquid extraction using methyl tert-butyl ether (MTBE). Extracted analytes were separated by reversed-phase liquid chromatography using a C8 column under gradient condition. All 16 analytes were detected, quantified and confirmed using a triple quadrupole tandem mass spectrometry with selected reaction monitoring (SRM) in both negative and positive electrospray ionization modes. The limit of detection, quantification and confirmation of the analytes were 1.0 - 5.0 ng/mL, 1.0 - 5.0 ng/mL and 1.0 - 20 ng/mL, respectively. The linear dynamic range of quantification was 5.0 - 200 ng/mL. The method is routinely used in anti-doping analysis to control the abuse of NSAIDs in racehorses competing in PA.

马白血病复合征(Equine lenkemia Complex)

马的血液及淋巴系统的新生物,绝大部分是由淋巴样细胞产生的,其他型细胞发生的很少见。美国加利福尼亚Dayvis大学的附属家畜病院,在经过组织学诊断的马肿瘤中,发现白血病仅次于鳞状细胞癌、类肉瘤,黑素瘤及卵巢粒层细胞瘤占肿瘤发生率的第五位。马恶性淋巴瘤(EL),依据其临床经过可有发病后很快即死亡的急性型与可生存几个月甚至几年的慢性型。