Naturally Occurring Acute Coliform Mastitis in Holstein Cattle

Physical examination and clinicopathologic findings from 44 adult Holstein cows with naturally occurring coliform mastitis were studied. The cattle were grouped for comparison by stage of lactation and survival. Cattle within the first 4 weeks of lactation maintained higher median mature neutrophil counts (1,200 versus 300/μL) in peripheral blood than cattle later in lactation. Nonsurviving cows had higher median creatinine concentration (2.5 versus 1.6 mg/dL) and anion gap (25 versus 20 mEq/L), and lower serum protein (7.1 versus 7.6 gm/dL) and total CO₂ (19.8 versus 25 mEq/L) concentrations than surviving cows (P < .05). These findings indicate that cattle with uremia and metabolic acidosis are less likely to survive the infection. Bacteriologic blood cultures were performed on 34 of the 44 cows studied. Esche-richia coli was isolated from the blood in 11 (32%) cows. Clinical presentation and clinicopathologic data were compared in bacteremic versus nonbacteremic cows to evaluate these data as predictors of bacteremia. Bacteremic cows were sick longer prior to admission (2 versus 1 days), maintained higher median counts of total nucleated cells (6.6 versus 2.4 × 10³ cells/μL), myelocytes (0.2 versus 0 × 10³ cells/μL), metamyelocytes (0.5 versus 0.02 × 10³ cells/μL), band neutrophils (0.7 versus 0.1 × 10³ cells/μL), and lymphocytes (2.1 versus 1.4 × 10³ cells/μL) than nonbacteremic cows, and had higher plasma fibrinogen concentration (600 versus 500 mg/dL) (P < .05). There were no differences between the physical or serum biochemical measurements. Four of 11 bacteremic cows and 5 of 23 nonbacteremic cows died or were euthanized (P > .05). The high prevalence of bacteremia seen in cows with coliform mastitis has not been reported previously, and may have been due to the duration of disease, severity of signs, or culture technique. These findings suggest that systemic antibiotic therapy may be beneficial in some severe cases of coliform mastitis. J Vet Intern Med 1996;252–257. Copyright©1996 by the American College of Veterinary Internal Medicine.     

Effect of Preoperative Erythromycin or Dexamethasone/Vitamin C on Postoperative Abomasal Emptying Rate in Dairy Cows Undergoing Surgical Correction of Abomasal Volvulus

Objective— To determine the effects of preoperative erythromycin or combined dexamethasone/vitamin C treatment on postoperative abomasal emptying rate in cows undergoing surgical correction of abomasal volvulus (AV).
Study Design— Prospective, controlled, clinical study using a convenience sample.
Animals— Lactating Holstein–Friesian cows (n=45) with AV were alternately assigned to 3 groups (n=15): group C: untreated (control); group E: erythromycin (10 mg/kg intramuscularly [IM]); group D: dexamethasone (0.02 mg/kg intravenously [IV]) and vitamin C (10 mg/kg IV).
Methods— Drugs were administered 1 hour before surgical correction of AV. d -xylose solution (50%, 0.5 g/kg body weight) was injected into the abomasal lumen during surgery. Jugular venous blood samples for determination of serum d -xylose concentration were periodically obtained. Time to maximal serum d -xylose concentration (T_max-model) was pharmacokinetically determined.
Results— Abomasal emptying rate was significantly ( P <0.05) faster in group E (T_max-model=182±69 min; mean±SD) than in group C cows (T_max-model=237±64 min). Abomasal emptying rate was similar in group D (T_max-model=196±47 min) and group C. Both treatments improved postoperative milk yield within 1 day after surgery.
Conclusion— Preoperative injection of erythromycin (10 mg/kg IM) is an effective method for ameliorating postoperative abomasal hypomotility in cows with AV.
Clinical Relevance— Parenteral erythromycin can be recommended for preoperative treatment of cows with AV.     

Primary Repair of Abomasal Fistulae Resulting From Right Paramedian Abomasopexy in Eight Adult Dairy Cattle

Abomasal fistulae resulting from right paramedian abomasopexy in eight adult dairy cattle were treated by primary closure of the abdominal wall after surgical resection of the fistulae. The median elapsed time from the abomasopexy to recognition of fistula formation was 16 days (range, 10 to 90 days). All cows had normal electrolyte values, and five cows had mildly increased base excess values (range = 4.0 to 7.8 mEq/L). Surgery was performed with the cows in dorsal recumbency using general anesthesia. The fistulated tissue was resected and the abomasum and body wall were closed primarily. One or two layers of appositional sutures using #2 or #3 polyglactin 910 were used to close the body wall. Mean surgical time was 2.2 hours (range, 1.8 to 2.9 hours). Two cows were lost to follow-up. Five of the remaining six cows returned to production (range, 5 to 30 months). Primary closure of the abdominal wall should be considered in the surgical repair of abomasal fistulae in cows that do not have diffuse peritonitis.     

Abomasal Nematodes in Cattle in Ontario

During 1970, 93 abomasa from cattle in Ontario were examined, and from 63 of these abomasa nematode species of the genera Ostertagia, Haemonchus and/or Trichostrongylus axei were recovered. The abomasa were from cattle six months to two years of age and were collected either from the postmortem room at the Ontario Veterinary College or from two abattoirs near Guelph. The numbers of worms per abomasum were estimated and their genera were identified from a one-twentieth volume of the washings and contents. The prevalence of Ostertagia species was estimated by examining random samples of adult male worms. Morphological variations in the species of the genera Ostertagia and Haemonchus were estimated by examining random samples of adult females. The predominant nematode was Ostertagia ostertagi. Other Ostertagia species recovered were O. trifurcata, O. lyrata and O. circumcincta. The numbers of nematodes recovered were generally low. Adult Ostertagia females had well-developed vulvar flaps. However, in abomasa where adult male O. trifurcata and O. lyrata were found, some adult female Ostertagia worms had reduced or no vulvar flaps. In two abomasa, adult Haemonchus females had large pendulous or “linguiform” vulvar flaps, and adult males had mean spicule lengths of 517 and 512 μ and were, therefore, unlike any of the recognized Haemonchus species.     

Ischaemia/Reperfusion Injury in Experimentally Induced Abomasal Volvulus in Sheep

The purpose of the study was to evaluate ischaemia/reperfusion injury in simulated abomasal volvulus in sheep. Sixteen ewes were randomly allocated to three groups. The control group (n = 4) served as sham-operated controls. The animals of the ischaemia group and reperfusion group (n = 6, each) underwent a simulated ‘abomasal volvulus’. The abomasum was exteriorized under general inhalation anasthesia and forced into a 180^∘ anticlockwise rotation around its longitudinal axis, followed by another 270^∘ anticlockwise rotation around its transectional axis. All ewes were monitored for 4 h. In the reperfusion group, volvulus was released after 3 h (i.e., 1 h of reperfusion). In the ischaemia group, the volvulus remained for 4 h (no reperfusion). Vital signs were monitored and some haematological and biochemical parameters were measured, without any significant differences. Full-section biopsy specimens were taken at the 3rd and 4th hours from the greater curvature of the abomasum. Histopathological lesions were scored according to the severity of mucosal oedema, submucosal oedema, haemorrhage submucosal and submuscularis layers, and polymorphonuclear infiltration on a scale of 0 to 4 (nil, mild, moderate, severe, and extreme). Another biopsy specimen was taken at the 4th hour for transmission electron microscopic examination. The scored lesions in light-microscopic examination were significantly different at the 3rd and 4th hours between the control and the experimental groups (p<0.05). There was no significant difference between the reperfusion and ischaemia groups (p>0.1). Within-group comparisons (3rd hour with 4th hour) revealed no significant differences. In transmission electron microscopic examination there were no remarkable changes in the control group, but in the ischaemia and reperfusion groups there were remarkable cellular (epithelial and goblet cells), mitochondrial and microvillous changes that strongly implied the occurrence of ischaemia (p<0.05). In transmission electron-microscopic examination of abomasal samples the lesions were more remarkable in reperfusion group than in the ischaemia group. It is concluded that ischaemia/reperfusion injury occurred in this model of simulated abomasal volvulus in sheep and that ischaemia/reperfusion injury should be considered as a potential determining factor in the outcome of cattle with abomasal volvulus.     

奶牛真胃变位的发病规律与预防措施

奶牛真胃变位是指真胃（皱胃）由正常的解剖位置发生改变，并且超过了正常的生理范围而引起消化机能障碍，导致营养代谢失调的急性内科疾病。在临床上可以分为左方变位和右方变位。临床上习惯把右方变位称为真胃扭转。奶牛真胃变位的发病率为2．5％～5％左右，其中85％～88％的病例为左方变位．右方变位的病例较少。随着奶牛养殖业的发展．该病的发病率逐年升高，死亡率较高．成为威胁奶牛养殖业发展的一种严重疾病。现就该病的发病规律和防治方法简单介绍如下．供参考。     

119例奶牛真胃移位的诊治

自2002年春至2005年上半年,笔者与同事在四川雅安地区先后治疗了119例真胃移位的奶牛,确诊后实施手术疗法,114例恢复,治愈率95.8%。119例真胃移位的奶牛,其中110例为左方移位,占92.4%;9例为右方移位(真胃扭转),占7.7%。现将其诊断与手术治疗情况汇报如下:1诊断1.1发病情况119例     

Naturally Occurring Scrapie in Southdown Sheep

The purpose of this study was to characterize naturally occurring scrapie in the Southdown breed of sheep. Experimental subjects included 4 Southdown ewes admitted to the University of Missouri, College of Veterinary Medicine Large Animal Clinic. All 4 sheep had signs compatible with clinical scrapie. Cerebrospinal fluid (CSF) cell counts ranged from a low of 1 nucleated cell/microL to high of 4 cells/microL with a median of 3 cells/microL. Cerebrospinal protein concentrations ranged from 26 to 78 mg/dL with a median of 53 mg/dL. Immunoassay of the CSF for the 14-3-3 protein yielded positive results in 3 of the 4 sheep. Sequencing of the prion protein (PrP) gene revealed that all 4 sheep were homozygous for glutamine at codon 171 and, hence, were of the QQ genotype. Histopathologic examination of brain stem tissue sections revealed intracytoplasmic neuronal vacuolation and mild spongiform changes in the gray matter neuropil in all 4 ewes. The diagnosis of scrapie was confirmed by immunohistochemical staining for the abnormal PrP Our results suggest that the genetics of scrapie susceptibility are probably similar in Suffolk and Southdown sheep. Positive immunoassay results for the 14-3-3 protein were observed in 3 of the 4 sheep.     

Naturally Occurring Histoplasmosis in Guinea Pigs

Histoplasmosis naturally occurring in laboratory guinea pigs is described in its clinical, necropsy, histological and mycological aspects.

The animals if adult show a chronic disease with progressive emaciation and lameness of the hind legs. The young below three months of age died in 2 to 4 weeks presenting ruffled fur, great dorsal curvature and sometimes closed eyelids and catarrhal conjunctivitis.

At necropsy the principal lesions were ulcerative gastritis, hemorrhagic and catarrhal enteritis, enlarged spleen and mesenteric lymph nodes. Sometimes the liver, lungs, mediastinal lymph nodes and other organs showed lesions.

Histological and mycological demonstration of the fungus completed the diagnosis and the surviving animals were burned and sanitation measures instituted.

Histological evidence of histoplasmosis in a cow's lung from the area from which the grass was obtained for the feeding of the guinea pigs suggests an epidemiological link. Efforts will be made to isolate and demonstrate H. capsulatum in wild animals on the same area.

     

真胃变位奶牛抗氧化能力研究

为了阐明奶牛发生真胃变位(abomasal displacement,DA)时机体抗氧化能力的变化规律,本试验采用分光光度法对27头真胃左方变位奶牛与13头健康奶牛血浆总超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、总抗氧化能力(T-AOC)、丙二醛(MDA)含量进行了测定.结果 表明,与健康奶牛相比,...     

奶牛真胃变位发病原因研究进展

奶牛真胃变位的发病原因可能与真胃壁中肠道神经元功能性紊乱有关,这对揭示奶牛真胃变位的发病机制有重要意义.真胃变位奶牛肠道神经元的一氧化氮合酶活性升高,乙酰胆碱敏感性降低,真胃的运动力减弱和排空机能受损可能与这种异常关系有关,即抑制肠道神经元的增强活性,皱胃肌肉的胆碱能神经敏感性降低.流行病学调查和试验研究已证实真胃迟缓和真胃扩张是奶牛真胃变位的主要原因,同时,品种、遗传背景、双胎、泌乳早期阶段(特别是第1周)富含高精料日粮而缺乏优质粗饲料、代谢紊乱性疾病(酮病、脂肪动员增加、胰岛素抗药性)和其他并发疾病(子宫内膜炎、乳房炎、蹄病)等都是真胃变位发生的诱发因素.     

奶牛皱胃变位病因及发病机制研究进展

奶牛皱胃变位是指皱胃的正常解剖位置发生改变,导致消化机能障碍的内科疾病。此病多发于高产奶牛,造成了巨大的经济损失。论文通过对遗传、品种、胎次及生产水平、发病时期、营养和新陈代谢及环境等来综述奶牛皱胃变位的病因,从皱胃弛缓学说和机械因素学说两方面综述其发病机制研究进展,为该病的有效预防和控制提供理论基础。     

Twinning in Dairy Cattle

Twinning in dairy cattle is an unavoidable outcome of reproduction and is undesirable because it reduces the overall profitability of a dairy operation through negative effects on cows calving twins as well as on calves born as twins. Cows calving twins are at greater risk for many periparturient reproductive and metabolic disorders than nontwinning herdmates, and incidences of abortion, stillbirth, neonatal calf mortality, and reduced birth weight are greater among twin compared with singleton calves. Twinning is a complex trait with multiple causative factors, and empirical evidence supports a role for both genetic and environmental risk factors in cattle. Risk factors for twinning include genetics, season, parity, ovulation rate, and milk production. The observation that twinning has increased in the dairy cattle population over time suggests a concurrent change in one or more of these causative factors during this same period. At present, dairy farmers and their consultants are ill prepared to make sound-management decisions to mitigate the negative effects of twinning on their operations because of a lack of applied scientific data on management strategies for periparturient dairy cows carrying twin fetuses. A clear understanding of the factors responsible for twinning is essential for future development of strategies to manage twinning in dairy operations.     

Experimental Duodenal Obstruction in the Horse

An experimental study of duodenal obstruction was performed on four horses to determine the relation between the volume of accumulated fluid in the stomach and the degree of dehydration and acid-base disturbances. After a rapid increase, the production of fluid decreased slowly and ceased within 38 hours. The production averaged 0.31/100 kg body weight/hour. A continuing increase in packed cell volume was observed after the cessation of fluid production and the release of the obstruction. After the initial metabolic alkalosis, one horse had a metabolic acidosis, whereas two remained slightly alkalotic during the time of the duodenal obstruction. Acid-base values were within normal limits in one horse.     

一例奶牛真胃不全扭转的诊治

本文报道了南京地区某奶牛场1例奶牛的发病情况、临床症状、剖检变化、诊断和治疗过程,经临床检查和剖腹探查确诊为真胃不全扭转,并通过手术和药物治疗及加强护理,病牛康复。     

应用DHI对某奶牛群生产性能的综合分析

应用DHI对某奶牛群生产性能进行综合分析,探索在奶牛牧场管理过程中,牛奶体细胞数SCC与奶牛产奶量、健康、胎次的关系,以期应用DHI提高奶牛生产性能。应用奶牛生产性能测定(DHI)体系对900头产奶牛进行测定和分析,发现在奶牛泌乳的各个阶段,随着牛奶体细胞数增高,各胎次奶牛产奶量呈逐渐下降趋势;体细胞数随着胎次的增加而上升,奶牛产奶量随奶牛胎次的变化而变化。奶牛存在产犊间隔长,繁殖障碍和营养问题,需采取相应的改进措施。