Lameness of horses is effectively ameliorated with a low volume of mepivacaine administered as a palmar digital nerve block.

Objective: To determine the effect of 1.5 mL 2% mepivacaine, 0.75 mL 2% mepivacaine, and a combination of 0.

Comparison of speed of onset and analgesic effect of 2% mepivacaine hydrochloride deposited within or outside the neurovascular bundle at the level of the proximal sesamoid bones in horses with naturally occurring forefoot-related lameness.

Objective: To compare the speed of onset and analgesic effect of mepivacaine deposited within or immediately outside the neurovascular bundle at the base of the proximal sesamoid bones in horses.

Animals: 6 horses with naturally occurring forefoot-related lameness.

Procedures: In a crossover study design, horses were randomly assigned to receive 1 of 2 treatments first, with the second treatment administered 3 to 7 days later.

Effect of 3% chloroprocaine hydrochloride when used for median and ulnar regional nerve blocks in lame horses.

Objective: To assess onset of analgesia for 3% chloroprocaine hydrochloride and 2% mepivacaine hydrochloride when used for median and ulnar nerve blocks in lame horses.

Animals: 6 naturally lame horses.

Procedures: A crossover experiment was conducted.

Effect of the addition of epinephrine to a lidocaine solution on the efficacy and duration of palmar digital nerve blocks in horses with naturally occurring forefoot lameness.

OBJECTIVE To determine whether addition of epinephrine to a lidocaine solution would prolong and potentiate the efficacy of a palmar digital nerve block (PDNB) in horses. ANIMALS 6 adult horses with naturally occurring forefoot lameness. PROCEDURES Initially, a PDNB with a 2% lidocaine solution was performed on the affected foot of each horse.

Effect of exercise and environmental terrain on development of the digital cushion and bony structures of the bovine foot.

Objective: To determine whether exercise on alternative terrain affects the development of the digital cushion and bony structures of the bovine foot.

Animals: 20 weaned bull calves.

Procedures: Two-month-old calves were randomly allocated to an exercise or control group.

Staphylococcus aureus shedding pattern throughout lactation in dairy cows with naturally occurring intramammary infection.

Objective: To evaluate shedding patterns of Staphylococcus aureus, specifically the association between clonal relatedness and shedding patterns of S aureus for cows with naturally occurring S aureus intramammary infection.

Design: Longitudinal field study.

Sample: Milk samples from 22 lactating cows (29 mammary glands) of varied numbers of lactations on 2 dairies.

Evaluation of intra-abdominal pressure in horses that crib.

Objective: To measure intra-abdominal pressure (IAP) in horses that crib and compare it with IAP in horses that do not have this vice.

Study Design: Cohort study.

Animals: Healthy cribbing horses (cribbing cohort, n = 8) and 8 healthy noncribbing horses (noncribbing cohort).

Yersinia enterocolitica of porcine origin: carriage of virulence genes and genotypic diversity.

Yersinia enterocolitica is an important foodborne pathogen, and pigs are recognized as a major reservoir and potential source of pathogenic strains to humans. A total of 172 Y. enterocolitica recovered from conventional and antimicrobial-free pig production systems from different geographic regions (North Carolina, Ohio, Michigan, Wisconsin, and Iowa) were investigated to determine their pathogenic significance to humans.

Variation in daily shedding patterns of Staphylococcus aureus in naturally occurring intramammary infections.

The goal of the current prospective field study was to examine the shedding patterns of naturally occurring Staphylococcus aureus intramammary infections and the association of pulsed field gel electrophoresis pulsotype with shedding. Milk samples from 5 multiparous and 2 primiparous cows identified with S. aureus intramammary infections were collected for 21 consecutive days, 3 times throughout the lactation (63 days total).

Milk yield and somatic cell count during the following lactation after selective treatment of cows at dry-off.

Selective dry cow therapy (SDCT) has received increasing attention in recent years owing to global concerns over agricultural use of antimicrobial drugs and development of antimicrobial resistance. The objective of this study was to evaluate the effect of SDCT on milk yield and somatic cell count (SCC) in dairy herds in the USA. Cows in four Ohio dairy herds were categorized into two groups (low-SCC and high-SCC) at dry-off based on their SCC and clinical mastitis (CM) history during the lactation preceding the dry-off.

The effect of inoculum volume on the microbiologic detection of naturally occurring Staphylococcus aureus intramammary infections.

Currently no standard definitions for the diagnosis of Staphylococcus aureus intramammary infection (IMI) exist. As a result, criteria applied in research to diagnose S. aureus IMIs have varied making comparisons between published works difficult.

Association of milk yield and infection status at dry-off with intramammary infections at subsequent calving.

The dry period plays an important role in maintenance of udder health. Cows are most susceptible to intramammary infections (IMI) after dry-off and near parturition and drying-off procedures may affect the likelihood of IMI at calving. The objective of this study was to evaluate the association of milk yield and infection status at dry-off with the likelihood of IMI at calving by examining different drying-off methods.

Lactoferrin concentrations in bovine milk prior to dry-off.

Concentration of natural protective factors (NPFs) which have the ability to inhibit growth of mastitis-causing pathogens increase rapidly following the cessation of milking of dairy cows. One such NPF is lactoferrin, an iron-binding protein present in high concentrations in dry-cow secretions. Earlier studies have demonstrated that intermittent milking at the end of lactation increases levels of NPFs in milk and may decrease prevalence of intramammary infections at calving; however, most of these studies date back several decades and may not apply to current high-producing cows.

Diagnosis of intramammary infections at dry-off based on sampling strategy, epidemiology of pathogens, and agreement beyond chance.

Isolation of pathogens from duplicate or multiple milk samples is currently considered the gold standard in diagnosis of bovine intramammary infections (IMI). However, in large field studies and especially in normal dairy production conditions, collection of single samples is often the most practical option to determine the causal agents of mastitis in a herd. The objective of the present study was to determine how well results between the first and the second sample in pairs of duplicate and successive quarter milk samples agree, using 5 different IMI definitions, based on the number of colony forming units (CFU) per milliliter of milk and epidemiology of the pathogens isolated.

A new approach to teaching veterinary public health at the Ohio State University.

Public-health practitioners with expertise in the area of veterinary public health are expected to understand the prevention and control of zoonotic infectious diseases in both human and animal populations. This focus on multiple species is what makes the veterinary public health (VPH) official unique. The development of a new VPH specialization within the existing Master of Public Health (MPH) degree program at the Ohio State University represents a significant new collaboration between the College of Veterinary Medicine and the College of Public Health.

Using dairy herd improvement records and clinical mastitis history to identify subclinical mastitis infections at dry-off.

Interest in selective dry cow therapy (SDCT) has been increasing owing to concerns over development of antimicrobial resistance. Implementation of SDCT, however, requires a quick and cost-effective on-farm method for identifying cows for treatment and cows that can be left without treatment. The objective of the present study was to evaluate the use of clinical mastitis (CM) history and somatic cell counts (SCC) from monthly Dairy Herd Improvement (DHI) records in identification of infected and uninfected cows at dry-off.

Screening the whole genome of a pathogen in vivo for individual protective antigens.

We report the results of a general protocol that was used to screen the whole genome of Chlamydophila abortus, type strain B577 (formerly Chlamydia psittaci strain B577), in a mouse pneumonia model. Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system.

High prevalence of natural Chlamydophila species infection in calves.

We investigated the acquisition and prevalence of Chlamydophila sp. infection in calves. Specimens were collected at weekly intervals from birth to week 12 postpartum from 40 female Holstein calf-dam pairs in a dairy herd.

Acid resistance systems required for survival of Escherichia coli O157:H7 in the bovine gastrointestinal tract and in apple cider are different.

Escherichia coli O157:H7 is a highly acid-resistant food-borne pathogen that survives in the bovine and human gastrointestinal tracts and in acidic foods such as apple cider. This property is thought to contribute to the low infectious dose of the organism. Three acid resistance (AR) systems are expressed in stationary-phase cells.

Reinfection with Chlamydophila abortus by uterine and indirect cohort routes reduces fertility in cattle preexposed to Chlamydophila.

This study investigated the effects of controlled reinfection on fertility of cattle naturally preexposed to Chlamydophila abortus. All animals had high prechallenge levels of immunoglobulin M (IgM), IgG, IgG1, and IgG2 serum antibodies against ruminant C. abortus in a chemiluminescent enzyme-linked immunosorbent assay.

Quantitative detection of Chlamydia psittaci and C. pecorum by high-sensitivity real-time PCR reveals high prevalence of vaginal infection in cattle.

Bovine vaginal cytobrush specimens were analyzed for the presence of Chlamydia spp. by a high-sensitivity, high-specificity quantitative PCR. The 53% prevalence of low-level Chlamydia psittaci and C.

Mastitis therapy and pharmacology.

Mastitis remains the most frequent cause of antibacterial use on dairy farms and contributes to a substantial portion of total drug and veterinary costs incurred by the dairy industry. Ultimately, the best outcome of mastitis therapy is a positive effect on the amount of marketed milk harvested and long-term survival of the cow. This article describes the strategies of therapy for bovine mastitis, with an emphasis on antibacterial and anti-inflammatory therapy.

High-sensitivity quantitative PCR platform.

Real-time PCR methods have become widely used within the past few years. However, real-time PCR is rarely used to study chronic diseases with low pathogen loads, presumably because of insufficient sensitivity. In this report, we developed an integrated nucleic acid isolation and real-time PCR platform that vastly improved the sensitivity of the quantitative detection of the intracellular bacterium, Chlamydia spp.

The quantity of nitric oxide released by macrophages regulates Chlamydia-induced disease.

Intracellular bacteria of the genus Chlamydia cause numerous typically chronic diseases, frequently with debilitating sequelae. Genetic determinants of disease susceptibility after infection with Chlamydia bacteria are unknown. C57BL/6 mice develop severe pneumonia and poor immunity against Chlamydia after moderate respiratory infection whereas BALB/c mice are protected from disease and develop vigorous Th1 immunity.