Effect of formic acid treatment on colostrum quality, and on absorption and function of immunoglobulins: a randomized controlled trial in Holstein dairy calves.

BACKGROUND: Good quality colostrum is characterized by high immunoglobulin concentration and low pathogen load. Some methods of pathogen reduction can decrease immunoglobulin concentration and potentially affect their function. Objectives were to determine the effect of formic acid treatment on colostral bacterial and immunoglobulin (IgG) levels before feeding, and serum immunoglobulin concentration and neutralizing capabilities after feeding. Fifteen female Holstein calf pairs born < 12 h apart from different dams were randomly assigned to receive four liters of either untreated pooled (both dams) colostrum (MC) or colostrum acidified to pH 4.0-4.5 (AC). Colostrum characteristics estimated; pH, bacterial load, IgG concentration, and neutralization of Infectious Bovine Rhinotracheitis (IBRV/BoHV-1), Bovine Viral Diarrhea (BVDV) Types 1 and 2. Blood samples were collected on days 1, 3 and monthly for 6 months and were analyzed for IgG, and both viral plus leptospiral neutralization, and total protein (day 3 only). RESULTS: Compared to MC (mean 6.7, SD 0.4; median 6.8, range 6.0-7.3), AC pH was significantly reduced (mean 4.3, SD 0.2; median 4.3, range 4.0-4.5; P < 0.001). Total coliform count (cfu/mL) was also reduced (MC mean 149, SD 444; median 1, range 0-1,700; AC mean 8, SD 31; median 0, range 0-120; P = 0.02). Colostrum IgG concentration was not significantly different between MC (mean 93.3, SD 39.7; median 92.8, range 36.7-164.4 g/L) and AC (mean 101.9, SD 36.7; median 108.3, range 33.8-164.4 g/L; P = 0.54). In calves, serum IgG peaked on day 3 (MC mean 26.1, SD 34.9; median 169.2, range 8.3-151.0 g/L; AC mean 30.2, SD 48.7; median 188.8, range 3.1-204.4 g/L; P = 0.77), and apparent efficiency of IgG absorption was not different between groups (MC mean 24.3, SD 11.4, median 25.3, range 8.6-51.3%; AC mean 22.6, SD 21.7, median 21.6, range 4.1-58.9%; P = 0.65). Thereafter, IgG levels declined but did not differ between groups. MC and AC serum neutralizing titers for IBRV, BVDV Types 1 and 2, or Leptospira interrogans serovars Canicola, and Pomona and L. borgpetersenii serovar Hardjo were not different. CONCLUSIONS: Colostrum acidification significantly decreased bacterial load fed to newborn calves without affecting colostral IgG concentration or virus neutralization. In addition, acid treatment did not affect serum IgG concentration in calves or its activity against common pathogens.

Antimicrobial prescribing patterns of clinicians and clinical services at a large animal veterinary teaching hospital.

OBJECTIVE: To characterize antimicrobial prescribing patterns of clinicians and clinical services at a large animal veterinary teaching hospital and identify factors associated with antimicrobial prescribing. ANIMALS: All large animals (ie, equids, bovids, sheep, goats, camelids, swine, and cervids) evaluated at the New Bolton Center hospital at the University of Pennsylvania from 2013 through 2018. PROCEDURES: In a cross-sectional study design, data on antimicrobial use by clinicians and clinical services were collected from administrative and billing records. Multivariable regression modeling was performed to identify factors associated with antimicrobial prescribing patterns. RESULTS: Antimicrobials and critically important antimicrobials of the highest priority were dispensed in 42.1% (9,853/23,428) and 24.0% (2,360/9,853) of visits, respectively, and these proportions differed significantly among clinicians. Per visit, the median (interquartile [25th to 75th percentile] range) number of animal-defined daily doses dispensed was 3.6 (0.8 to 11.1) and the mean (SD) number of antimicrobial classes dispensed was 2.0 (1.3). Patient species, age, affected body system, and duration of hospitalization as well as submission of specimens for bacterial culture were significantly associated with prescribing patterns. CONCLUSIONS AND CLINICAL RELEVANCE: The frequency and quantity of antimicrobials prescribed differed significantly among clinicians within and across services, even for animals with clinical signs affecting the same body system. Patient- and visit-level factors explained some but not all of the heterogeneity in prescribing patterns, suggesting that other clinician-specific factors drove such practices. More research is needed to better understand antimicrobial prescribing patterns of clinicians, particularly in situations for which no antimicrobial use guidelines have been established.

Influence of Salmonella status on the long-term outcome of horses after colic surgery.

OBJECTIVE: To compare long-term outcome of Salmonella-positive versus Salmonella-negative horses discharged from hospital after colic surgery. STUDY DESIGN: Retrospective case-control. ANIMALS: Horses discharged from the hospital after colic surgery. For each horse with positive culture for Salmonella enterica (SAL-POS, n = 59), at least 2 horses testing negative for S. enterica (SAL-NEG, n = 119) were enrolled. METHODS: Owners were interviewed via phone at least 12 months after surgery regarding: (1) complications after discharge from the hospital; (2) duration of survival; and (3) return to prior or intended use. Association between immediate postoperative clinical variables such as Salmonella status and long-term measures of outcome was tested via ratios (odds ratio [OR]) and 95% confidence intervals. Data were analyzed for survival using a Cox proportional hazards model and for return to use using multivariable logistic regression. RESULTS: SAL-POS horses had a higher OR of surgical site infection (2.7 [1.1-6.9] P = .027) and weight loss (6.8 [1.8-26.1] P = .002). At the time of follow-up, there were 53/56 (95%) SAL-POS and 99/118 (84%) SAL-NEG horses alive. The final multivariable model for nonsurvival included postoperative colic (hazard ratio 7.6 [2.8-19.2] P = .002) and the interaction between Salmonella status and duration of rectal temperature > 103°F postoperatively (SAL-POS 1.04 [1.01-1.07] and SAL-NEG 1.16 [1.06-1.25], P = .005). The majority of horses returned to their intended use regardless of their SAL-POS (38/50, 76%) or SAL-NEG (77/96, 80%, P = .498) status. CONCLUSION: Salmonella-positive horses that survive to discharge from the hospital after colic surgery have similar risks of long-term complications (colic/diarrhea), survival, and return to function than Salmonella-negative horses.

Comparison of the antimicrobial activities of gallium nitrate and gallium maltolate against Mycobacterium avium subsp. paratuberculosis in vitro.

Johne's disease (JD) is an enteric infection of cattle and other ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). This study compared the antimicrobial activities of gallium nitrate (GaN) and gallium maltolate (GaM) against two field MAP isolates by use of broth culture. The concentrations that resulted in 99% growth inhibition of isolates 1 and 2 were, respectively, 636 µM and 183 µM for GaN, and 251 µM and 142 µM for GaM. For both isolates, time to detection was significantly higher for GaM than GaN. These results suggest that GaM is more efficient than GaN in inhibiting MAP growth in vitro.

Impact of colic surgery on return to function in racing Thoroughbreds: 59 cases (1996-2009).

OBJECTIVE: To determine the effect of colic surgery on return to function in Thoroughbred racehorses, identify clinical variables associated with successful return to racing, and compare racing performance between horses undergoing colic surgery and an untreated cohort. DESIGN: Retrospective cohort study. ANIMALS: 59 Thoroughbred racehorses 2 to 5 years of age that underwent colic surgery and survived to hospital discharge and 90 untreated Thoroughbred racehorses equivalent in class. PROCEDURES: Medical records of patients evaluated for colic between January 1996 and July 2009 were reviewed, and horses with a Jockey Club Information Systems record were included. Physical examination and laboratory findings on hospital admission, lesion location and type, duration of surgery, duration of hospitalization, and any postoperative complications were recorded. The untreated cohort comprised 2 untreated horses randomly selected from runners in each treated horse's last race immediately prior to the date of colic surgery. Records were obtained from the Jockey Club Information Systems in April 2011. Only horses that raced at least once before and after surgery were included in the performance analysis. Number of starts, earnings per start, and total earnings were determined from race records for all horses. Quarterly earnings and number of starts for 12 quarters following the date of surgery were compared between treated and untreated horses via a Wilcoxon rank sum test. Longevity of racing was assessed by means of survival analysis. Poisson regression was used to compare rates of return to racing and active quarters aggregated across the first 12 quarters after surgery and for the available follow-up period for treated and untreated horses. RESULTS: 45 of 59 (76%) horses that raced prior to surgery returned to racing. Return to racing was significantly associated with admission heart rate and blood lactate concentration. From quarters 3 to 12, treated and untreated horses had slight differences in the number of starts but no difference in earnings per quarter. Treated and untreated horses had no difference in total number of quarters raced, number of starts, or earnings after surgery. Treated horses had higher earnings per start, compared with untreated horses. CONCLUSIONS AND CLINICAL RELEVANCE: In the present study, racing Thoroughbreds that underwent colic surgery and successfully returned to racing had no differences in performance variables, compared with their untreated cohorts.

A field study of kick injuries to the radius and tibia in 51 horses (2000-2010).

The objective of this study was to examine all kick injuries to the radius and tibia seen in an ambulatory setting over an 11-year period in order to determine factors affecting outcome. Medical records of 51 horses seen for a kick injury to the radius or tibia were reviewed. Signalment, physical examination findings, type of management, and outcome were evaluated. There was a significant association between the presence of bony crepitus and a lameness score of ≥ 4/5 and a poor outcome. There was no relationship between signalment and outcome, but significantly more Thoroughbred/Thoroughbred cross horses were affected than any other breed. There was no detected relationship between the type of management and outcome; however, most (81%) horses were managed on stall rest. Horses with bony crepitus or with a lameness score of ≥ 4/5 were at an increased risk for euthanasia.

Une étude sur le terrain des blessures de ruades au radius et au tibia chez 51 chevaux (2000­2010). L'objectif de cette étude consistait à examiner toutes les blessures de ruades au radius et au tibia observées dans un milieu ambulatoire pendant une période de 11 ans afin de déterminer les facteurs qui affectent les résultats. Les dossiers médicaux de 51 chevaux examinés pour une blessure de ruade au radius ou au tibia ont été examinés. Le signalement, les constatations de l'examen physique, le type de gestion et les résultats ont été évalués. Il y avait une association significative entre la présence d'une crépitation osseuse et une cote de boiterie ≥ 4/5 et un résultat défavorable. Il n'y avait aucun lien entre le signalement et le résultat, mais un nombre significativement supérieur de chevaux Thoroughbred/Thoroughbred croisés étaient touchés par rapport à toute autre race. Il n'y a eu aucun lien détecté entre le type de gestion et le résultat; cependant, la plupart (81 %) des chevaux étaient gérés lors d'un repos en stalle. Les chevaux avec une crépitation osseuse ou une cote de boiterie de ≥ 4/5 présentaient un risque accru d'euthanasie.(Traduit par Isabelle Vallières).

Survival of Salmonella enterica serovar Newport in manure and manure-amended soils.

Salmonella enterica serovar Newport has undergone a rapid epidemic spread in dairy cattle. This provides an efficient mechanism for pathogen amplification and dissemination into the environment through manure spreading on agricultural land. The objective of this study was to determine the survival characteristics of Salmonella serovar Newport in manure and manure-amended soils where the pathogen may be amplified. A multidrug-resistant (MDR) Salmonella serovar Newport strain and a drug-susceptible (DS) strain, both bovine isolates, were inoculated into dairy manure that was incubated under constant temperature and moisture conditions alone or after being mixed with sterilized or nonsterilized soil. Salmonella serovar Newport concentrations increased by up to 400% in the first 1 to 3 days following inoculation, and a trend of steady decline followed. With manure treatment, a sharp decline in cell concentration occurred after day 35, possibly due to microbial antagonism. For all treatments, decreases in Salmonella serovar Newport concentrations over time fit a first-order kinetic model. Log reduction time was 14 to 32 days for 1 log(10), 28 to 64 days for 2 log(10), and 42 to 96 days for 3 log(10) declines in the organisms' populations from initially inoculated concentrations. Most-probable-number monitoring data indicated that the organisms persisted for 184, 332, and 405 days in manure, manure-amended nonsterilized soil, and manure-amended sterilized soil, respectively. The MDR strain and the DS strain had similar survival patterns.