Treatment of peracute and acute mastitis.

This article discusses the cause and pathophysiology of peracute and acute mastitis. The pharmaceutic and pharmacologic properties of potential therapeutic agents, the interaction between the cow and the drug, and some practical aspects of using these drugs are reviewed.     

Ovarian Follicular Dynamics. A review with Emphasis on the Bovine Species. Part II: Antral Development,Exogenous Influence and Future Prospects

During an oestrous cycle, a cohort of antral follicles develops into – depending on the species – one or more ovulatory follicles. The bovine oestrous cycle is characterized by two to three such cohorts or growth waves, only the last of which will result in an ovulation. In every growth wave, several antral follicles are recruited for development. Recruited follicles are subjected to a selection process, whereby ever decreasing levels of follicle stimulating hormone (FSH) are available to the FSH dependent follicles. In the cow, a single follicle from the cohort will acquire dominance. The ability of the dominant follicle to prosper under basic FSH levels is ascribed to a transition in hormone dependency from FSH to luteinizing hormone. The exact follicle selection mechanism remains, however, to be elucidated. The beginning of this article focuses on the recruitment, selection and dominance phases in antral follicle development. Subsequently, the conditions leading to successful maturation and ovulation are discussed. The next section expounds upon the mechanisms for exogenous modulation of follicular dynamics with the aim of superovulation/superstimulation, and finally prospective future research directions are sketched.     

Canine Idiopathic Dilated Cardiomyopathy. Part II: Pathophysiology and therapy

Dilated cardiomyopathy (DCM) in dogs is characterized by ventricular and atrial enlargement, and systolic and diastolic dysfunction, with congestive heart failure (CHF) often developing at some stage. With greater understanding of the impact of neuroendocrine stimulation in heart disease, the understanding of the pathophysiology for CHF has changed considerably. It is no longer considered only to be a simple haemodynamic consequence of pump dysfunction, but is now characterized as a complex clinical syndrome with release of many neurohormones, which are believed to have impact on the progression of disease. This change in our understanding of the pathophysiology of CHF has important therapeutic implications. There are strong indications, although not yet proven, that drugs designed to influence the neuroendocrine activity, such as Angiotensin Converting Enzyme (ACE) inhibitors and beta-receptors antagonists, are efficacious as adjunct therapy of heart failure attributable to DCM in dogs. The benefits of drugs designed to influence the myocardial contractile state (positive inotropes) have not been fully evaluated. However, evidence has emerged in recent years indicating that new types of positive inotropes may be beneficial in dogs with DCM. This review focuses on the neuroendocrine aspects of DCM and their possible therapeutic implications and the place for long-term inotropic support in dogs with DCM.     

昆明地区奶牛临床型乳房炎病原菌分离鉴定及药敏试验

对昆明地区多个奶牛场的奶牛临床型乳房炎病原菌进行分离、鉴定,从114份乳样中共分离出细菌13种305株,经培养特性、染色镜检、生化鉴定等,鉴定出金黄色葡萄球菌63株,占20.66%;表皮葡萄球菌26株,占8.52%;无乳链球菌53株,占17.38%;停乳链球菌23株,占7.54%;乳房链球菌19株,占6.23%;乳链球菌14株,占4.59%;粪链球菌15株,占4.92%;化脓链球菌14株,占4.59%;大肠杆菌48株,占15.74%;真菌12株,占3.93%。分别对分离菌株进行17种药物的敏感性试验,除真菌外,所有菌株对庆大霉素、新霉素、环丙沙星、诺氟沙星、林可霉素、乳肿康均高度敏感,对临床常用的青霉素、链霉素、鱼腥草等具有较强的耐药性。     

奶牛亚临床酮病对乳房炎发病情况和抗氧化功能的影响

为研究奶牛亚临床酮病与乳房炎的关系以及血液中的酮体成分对奶牛抗氧化功能的影响,以156头健康荷斯坦奶牛为试验动物（SCC〈200000／mL）,共筛选亚临床酮病奶牛69头（1．0mmol／L≤BHBA〈2．6mmol／L）作为试验组,根据年龄、胎次、产奶量、泌乳天数配对的69头奶牛作为时照组（血液BHBA〈1．0mmol／L）,监测乳房炎发病情况并在各组中选取12头奶牛检测血液酮体水平和抗氧化指标。结果表明亚临床酮病奶牛试验期间乳房炎的发病率为43．48％,对照组试验期间乳房炎的发病率为31．88％,但差异不显著（P〉0．05）;试验组奶牛乳房炎高发期为分娩后3～6周,对照组奶牛乳房炎发病时间为分娩后5～8周,亚临床酮病发病后1～3周内为乳房炎的高发期,占试验组奶牛乳房炎总发病比例的73．33％,试验组和对照组病原菌的组成无显著差异（P〉0．05）;试验组奶牛血液中T—AOC显著低于对照组（P〈0．05）,GSH—PX活力、MDA和N0显著高于对照组（P〈0．05）,血液ACAC浓度与GSH—PX活力呈显著正相关（P〈0．05,r=0．595）,ACAC浓度与NO呈显著正相关（P〈0．05,r=0．655）,T—AOC与MDA呈显著负相关（P〈0．05,r=0．533）。结果表明奶牛亚临床酮病可以导致乳房炎的发病率升高,但不是主要影响因素,亚临床酮病对乳房炎病原体构成无影响;外周血酮体水平升高导致机体总抗氧化能力的降低并引起机体脂质过氧化反应;谷胱甘肽过氧化物酶在发挥抗氧化功能时具有一定的抵抗力和自我调节能力。     

Effect of combination therapy with lactoferrin and antibiotics against staphylococcal mastitis on drying cows

We examined combination therapy with both lactoferrin (Lf) and antibiotics on clinical mastitis due to Staphylococcus aureus (S.aureus) on drying cows. The clinical symptoms of mastitic quarters were cured 81% of combination therapeutic quarters at 7 days post injection (dpi). Moreover, most of mammary gland secretions (MGSs) in combination therapeutic quarters were normal at 7 days after parturition. In the quarters with combination therapy, S.aureus counts, Lf concentrations and content rate of concanavalin A (Con A) low-affinity Lf decreased and were lower than in the quarters treated with Lf or antibiotics alone. The mRNA expression of tumor necrosis factor alpha (TNFalpha) of the quarters with combination therapy also decreased and was lower than that of the Lf or antibiotics treated. The mRNA expression of pro-inflammatory cytokines and chemokines in bovine mammary gland epithelial lined cells (BMEC) stimulated with Lf were lower than those of Con A low-affinity Lf stimulated BMEC. Moreover, Lf showed an inhibitory effect to the induction of pro-inflammatory cytokine mRNA expression when co-stimulated with Lf and Con A low-affinity Lf. Nuclear factor kappa B (NFkappaB) activation was also induced with Con A low-affinity Lf, and the inhibitory effects of Lf were also confirmed on BMEC co-stimulated with Lf and Con A low-affinity Lf. These results indicated that the efficacy of combination therapy with antibiotics and Lf caused antibacterial effect of antibiotics and inhibition of pro-inflammatory cytokine and chemokine production with Lf via the inhibition of NFkappaB activation.     

The relationship between the California mastitis test, Whiteside test, Brabant mastitis reaction, catalase test, and direct cell counting of milk

The aim of this work was to study the relationship between the reactions obtained by indirect methods of testing milk samples and the cell content, determined by direct cell counting after Prescott & Breed (1910). The indirect tests used were the California Mastitis Test (CMT), Whiteside Test (WsT), Brabant Mastitis Reaction (BMR), and the Catalase Test (CT).The results of the investigations are summarized below.Samples with cell values lying within fixed limits do not neces¬sarily conform to particular indirect test reactions.All four indirect tests have wide ranges of variation of cell level within a given reaction with considerable overlapping between reac¬tions.The standard deviation for cell levels within a given reaction is large, although this can be partly explained by the fact that the cell values are estimated rather than real. Correction for this produces only an insignificant decrease, however.The coefficient of correlation is a little higher for the correlation CMT—CC than for the other indirect tests and CC.When sample groups with different mean cell levels (calculated from the whole material) are compared, the variation ranges (dif¬ference between the largest and the smallest observation) and standard deviations arc generally the same for the different CMT reactions. However, the mean cell values, for different reactions lie at higher levels when the mean cell content of the whole material is higher. Similarly they are lower when the mean of the whole material is lower. This is, however, not true for 0 reactions.The mean cell values for CMT 4- and for 4- 4- reactions varied considerably in different herds.It was not considered acceptable, for any of the four indirect tests, to substitute reactions by average cell values, either to determine the mean cell value or to decide whether a sample is inacceptable, if this means that the sample has a cell content above a certain value.Negative and 4- reactions for CMT and WsT could possibly be replaced by a mean cell level, since the range of variation is not so wide here and the majority of samples giving these reactions contain less than 3xl0⁵ cells per ml.The possibility exists of combining indirect tests and direct cell counting to examine milk samples, so that samples with low reactions could be passed, while those with higher reactions would be examined by cell counting.The indirect tests differentiate milk at different cell levels. The possibility of using a particular indirect test depends on the cell level to be examined and on the degree of accuracy required.