新生犊牛脐炎并发脓毒性关节炎的诊治及防控

介绍1例犊牛脐炎并发关节炎的诊断与治疗情况,并对病死犊牛进行剖检观察病理变化,同时制定相应的产房管理制度,新生犊牛发病率大大降低,为新生犊牛的有效管理提供了参考。     

Gallium Maltolate as an Alternative to Macrolides for Treatment of Presumed Rhodococcus equi Pneumonia in Foals

Background

Macrolide‐resistant isolates of Rhodococcus equi are emerging, prompting the search for clinically effective alternative antimicrobials.

Hypothesis

The proportion of foals with ultrasonographic evidence of pneumonia presumed to be caused by R. equi that had a successful outcome when administered gallium maltolate (GaM) PO would not be more than 10% inferior (ie, lower) than that of foals receiving standard treatment.

Animals

Fifty‐four foals with subclinical pulmonary abscesses among 509 foals at 6 breeding farms in Kentucky.

Methods

Controlled, randomized, prospective noninferiority study. Foals with ultrasonographic lesions >1 cm in diameter (n = 54) were randomly allocated to receive per os either clarithromycin combined with rifampin (CLR+R) or GaM, and followed up for 28 days by daily physical inspections and weekly (n = 1 farm) or biweekly (n = 4 farms) thoracic ultrasound examinations by individuals unaware of treatment‐group assignments. Treatment success was defined as resolution of ultrasonographically identified pulmonary abscesses within 28 days of initiating treatment. Noninferiority was defined as a 90% confidence interval for the observed difference in CLR+R minus GaM that was ≤10%.

Results

The proportion of GaM‐treated foals that resolved (70%; 14/20) was similar to that of foals treated with CLR+R (74%; 25/34), but we failed to demonstrate noninferiority for GaM relative to CLR+R; however, GaM was noninferior to CLR+R treatment when results from a noncompliant farm were excluded.

Conclusions and Clinical Importance

Gallium maltolate is not inferior to macrolides for treating foals with subclinical pneumonia. Use of GaM might reduce pressure for macrolide‐resistance in R. equi.     

Failure of a Subunit Bovine Herpesvirus 1 Vaccine to Protect Against Experimental Respiratory Disease in Calves

In two experiments in which 31 calves were used, a bovine herpesvirus 1 subunit vaccine previously shown to elicit a strong immunological response in adult cattle failed to do so in younger animals and failed to protect against pneumonia caused by sequential exposure to virulent bovine herpesvirus 1 and Pasteurella haemolytica aerosols. One of the experimental groups had been previously inoculated with a live commercial vaccine but even this failed to elicit a strong immunological response. These results indicate that the calves were in a refractory state when immunized and may explain why similar vaccine failures occur in the field.     

The Intrauterine Treatment of the Retained Foetal Membrane in Dairy Goats by Ozone: Novel Alternative to Antibiotic Therapy

One of the major post‐parturient complications in dairy goats is the retention of foetal membrane (RFM), which negatively influences their health, reproductive efficacy and welfare. The aim of this study was to compare the efficiency of intrauterine either ozone (OZ) or antibiotic (AB) treatments to establish the use of OZ as a novel and potential alternative to AB therapy in does with the RFM. The study was performed on 7 herds of dairy goats (n = 563) kept in the farms in Croatia. The conception rate was 563 of 641 total matings or 87.83%. The does from selected farms were observed during early puerperium and were divided into animals without the RFM (n = 522) and with the RFM (n = 41), treated either with foam spray OZ (n = 21) or with foaming AB oxytetracycline tablets (n = 20). The does with the RFM were mated successfully and became pregnant next kidding season, regardless of the treatment applied. Treatment with OZ attained similar results to the standard AB therapy, indicating that it could be novel potential alternative therapy of the RFM in dairy goats.     

Pregnancy Diagnosis in Cats Using a Rapid, Bench-top Kit to Detect Relaxin in Urine

Relaxin is a pregnancy-specific hormone in the queen and is produced by the placenta. Both serum and urinary relaxin levels can be used to diagnose and monitor pregnancy in the cat; however, only serum levels are commonly measured in practice. The present study aimed to assess whether urine could be used for the rapid diagnosis of pregnancy at an early stage in domestic cats using a bench-top kit to detect relaxin. Paired serum and urine samples were collected during the first month of gestation in six cats. The samples were tested by applying neat serum, urine or urine diluted in non-pregnant cat serum to the Witness Relaxin kit. Relaxin concentrations in the paired samples were also measured by radioimmunoassay. All undiluted urine samples from pregnant cats tested negative using the bench-top kit; however, the kit was able to detect relaxin in urine after dilution with non-pregnant cat serum. Using this as the test sample, the kit was accurate at diagnosing pregnancy from 28 days after mating and some samples tested positive at 21 days after mating. This preliminary work could lead to the development of a home pregnancy test for cats.     

应用生物素-亲和素法检测实验性传染性法氏囊病病鸡体内的病毒分布与消长

应用生物素—亲和素(BA)法检测实验性传染性法氏囊病(IBD)鸡,在法氏囊、脾脏、盲肠扁桃体、胸腺、肝脏、肺脏、肾脏和心脏均检出了阳性细胞,并证明鸡传染性法氏囊病病毒(IBDV)最早定位于法氏囊滤泡髓质区的淋巴细胞胞浆内并进行复制,法氏囊滤泡的淋巴细胞是IBDV的主要靶细胞.接毒后ld,法氏囊滤泡就见有许多病毒;2～3d.病毒数量激增并达到高峰;4～5d,病毒数量维持较高水平;6～7d,病毒数量显著减少.本实验结果表明,BA法可以作为IBD的特异诊断方法,法氏囊可作为检测本病的首选器官,在法氏囊滤泡的髓质检出阳性淋巴细胞、阳性异染性白细胞和阳性巨噬细胞,或主要检出阳性巨噬细胞,均可作为本病的特异性诊断指标.     

Evaluation of a Macroscopic Plate Test and an Indirect Immunofluorescence Test to Detect Leptospiral Antibodies in Bovine Serum

A macroscopic plate test was found to be reliable and convenient for detection of Leptospira serotype pomona antibodies in bovine sera. However, the procedure was unreliable for detecting L. serotype canicola antibodies because of false positive reactions. An indirect immunofluorescence test and the microscopic agglutination test provided comparable results and they effectively detected serotype pomona antibodies in bovine sera.     

Tree-Based Methods as an Alternative to Logistic Regression in Revealing Risk Factors of Crib-Biting in Horses

Determining the risk factors might help in designing prevention of crib-biting. Logistic regression is a commonly used statistical method for finding risk factors, but tree-based methods are also getting more popular. An important difference between these two statistical approaches is that logistic regression makes a number of assumptions about the underlying data, whereas tree-based methods do not. Another difference is that logistic regression can be used to derive odds ratios for the significant risk factors, whereas tree-based methods create a tree where the ramifications represent the risk factors. The probability of occurrence is assigned to each end of branch in the tree. Data of horses used for noncompetition purposes were analyzed with three statistical approaches: logistic regression, classification tree, and conditional inference tree methods. By this, we compared the advantages and disadvantages of these statistical methods. No difference was found between the two tree-based methods regarding the structure and prediction accuracy of the trees. Compared to them, logistic regression revealed fewer risk factors, and also the number of the stereotypic horses classified correctly by the model was less. The representation of the tree-based methods is closer to medical reasoning and also high-order interaction of the risk-factors can easily be visualized. Our results suggest that tree-based methods can be a new alternative in revealing risk factors, even if used alone or together with logistic regression.     

The Ability of the Enzyme‐Linked Immunosorbent Assay to Detect Antibody against Staphylococcus aureus in Milk following Experimental Intramammary Infection

Changes in the milk antibody levels against Staphylococcus aureus were measured at the start of an experimental intramammary instillation of either S. aureus (Study I) or Staphylococcus hyicus (Study II). A commercial enzyme‐linked immunosorbent assay system was used. Twenty‐one Holstein cows were enrolled in Study I and 15 Holstein cows were used in Study II. Pathogen instillation began 21 days before the start of the non‐lactating period. Cows received intramammary antibiotic treatment in all quarters immediately after the last milking, the start of the non‐lactating period. Lacteal secretions were collected before the start of the non‐lactating period, and during the immediate postpartum period in both studies, and during the non‐lactating period in Study I. Milk was cultured for mastitis pathogens and S. aureus antibody levels and somatic cell counts were determined from all samples. There was an approximate 2‐week delay in the elevation in antibody levels in response to the instillation of S. aureus. Antibody levels remained elevated in cows with S. aureus intramammary infections postpartum, but were below threshold in cows where intramammary infections were cured during the non‐lactating period. Antibody levels were elevated by S. hyicus intramammary infections, remained elevated for the first 12 days postpartum, but were below threshold by day 21 postpartum. Cows with incipient intramammary S. aureus infections might be misclassified as false negatives by the antibody test. However, results suggest that cows with S. hyicus intramammary infections that were not cured would not be misclassified if milk is withheld from test for the first 30 days postpartum, as recommended by the manufacturer of the test.     

Pasteurellosis in Reindeer in Northern Norway: A Contribution to its Epidemiology

Lung inflammations in reindeer caused by Pasteurella multocida were reported from Scandinavian countries already at the beginning of this century. Several outbreaks have been recorded in reindeer herds in Norway. Observations made at the fall reindeer slaughtering, and in reindeer herds in Finnmark seem to indicate an endemic state of this infection with subclinical carriers. Predisposing factors and lowered specific immune status may probably play important roles when fatal outbreaks occur.     

Comparison of Five Radioimmunoassay Systems for PAG Measurement: Ability to Detect Early Pregnancy in Cows

This study was conducted to describe the minimum detection limit, reproducibility, accuracy, specificity and parallelism of different pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) systems: RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool. Their ability to distinguish between non-pregnant and pregnant females at day 30 after artificial insemination (AI) was investigated. The antisera were raised in rabbits against different PAG preparations. All RIA systems proved to be sensitive, repeatable and accurate for measuring PAG concentrations. The dilutions of plasma samples taken at an early stage of pregnancy were found to be parallel to the standard curves. No cross-reaction was observed with different carbohydrates, either with Pregnant Mare Serum Gonadotropin (PMSG) or human Chorionic Gonadotropin (hCG). The concentrations of PAG in pregnant females at day 30 after AI were shown to be higher with the use of antisera R#706, R#780, R#809 and Pool when compared with antiserum R#497. All the RIA systems gave 100% sensitivity and negative predictive values. On the other hand, the use of antisera R#780 and R#809 resulted in lower specificity and positive predictive values. The present study clearly shows that the ability of PAG-RIA systems to diagnose pregnancy specifically at day 30 after AI can be improved by using a combination of antisera raised against different forms of PAG.