Jennifer A. Schleining

Identification of a Divergent Lineage Porcine Pestivirus in Nursing Piglets with Congenital Tremors and Reproduction of Disease following Experimental Inoculation

Congenital tremors is a sporadic disease of neonatal pigs characterized by action-related repetitive myoclonus. A majority of outbreaks of congenital tremors have been attributed to an unidentified virus. The objectives of this project were to 1) detect potential pathogen(s) in samples from piglets with congenital tremors and 2) develop an infection model to reproduce disease. Using next-generation sequencing, a divergent lineage pestivirus was detected in piglets with congenital tremors. The virus was originally most closely related to a bat pestivirus but is now more closely related to a recently published novel porcine pestivirus provisionally named atypical porcine pestivirus. A quantitative real-time PCR detected the virus in samples from neonatal piglets with congenital tremors from two separate farms, but not in samples from unaffected piglets from the same farm. To fulfill the second objective, pregnant sows were inoculated with either serum containing the pestivirus or PBS (control) by intravenous and intranasal routes simultaneously with direct inoculation of fetal amniotic vesicles by ultrasound-guided surgical technique. Inoculations were performed at either 45 or 62 days of gestation. All sows inoculated with the novel pestivirus farrowed piglets affected with congenital tremors while PBS-inoculated control piglets were unaffected. Tremor severity for each piglet was scored from videos taken 0, 1 and 2 days post-farrowing. Tremor severity remained relatively constant from 0 to 2 days post-farrowing for a majority of piglets. The prevalence of congenital tremors in pestivirus-inoculated litters ranged from 57% (4 out of 7 affected piglets) to 100% (10 out of 10 affected piglets). The virus was consistently detected by PCR in tissues from piglets with congenital tremors but was not detected in control piglets. Samples positive by PCR in greater than 90% of piglets sampled included brainstem (37 out of 41), mesenteric lymph node (37 out of 41), tracheobronchial lymph node (37 out of 41), and whole blood (19 out of 20). Although the first description of congenital tremors was in 1922, this is the first reported reproduction of congenital tremors following experimental inoculation with a divergent lineage porcine pestivirus. Studies investigating disease mechanism, epidemiology, and diagnostic assay development are needed to better understand the pathophysiology of congenital tremors due to this pestivirus.

Assessment and Management of Pain in Small Ruminants and Camelids

Many disease processes and management procedures of small ruminants have the potential to result in painful or noxious stimuli. There are a variety of medications and interventions that can be used to minimize the long-term consequences of pain in these species. The first portion of this article focuses on the commonly used medications available for pain management of small ruminants and discusses the benefits and side effects to their use. The second portion of the article focuses on the management of pain associated with common diseases or procedures of these species.

Liposome-based diclofenac for the treatment of inflammation in an acute synovitis model in horses

Lameness as a result of joint disease is a major source of decreased athletic performance in the horse. Most treatment protocols include the administration of nonsteroidal anti-inflammatory drugs (NSAIDs). Phenylbutazone, alone or in combination with other treatments, is the most commonly and widely used NSAID, however it has the potential for serious side effects. The introduction of the liposome-based formulation of the NSAID diclofenac has shown promising effect as a safe and convenient treatment for lameness associated with osteoarthritis. The purpose of this study was to evaluate the effect of topical liposome-based diclofenac in an acute inflammation model using subjective lameness scores and objective lameness evaluation, carpal surface temperature and circumference, synovial fluid cell count and total protein content, and the biochemical markers interleukin-1 (IL-1), IL-6, and prostaglandin E(2) as determinants of inflammation. In this acute inflammation model, there was no overall difference between treatment and control groups.

Bioavailability and pharmacokinetics of oral meloxicam in llamas.

BackgroundSouth American camelids in the United States have rapidly developed into an important agricultural industry in need of veterinary services. Pain management is challenging in camelids because there are no drugs currently approved by the U.S. Food and Drug Administration for use in these species. Dosage regimens used for many therapeutic drugs have been extrapolated from other ruminants; however, the pharmacokinetics, in camelids, may differ from those of other species. Studies investigating the pharmacokinetics of cyclooxygenase-2 (COX-2) selective non-steroidal anti-inflammatory drugs in camelids are deficient in the published literature. Six adult llamas (121- 168 kg) were administered either a 1 mg/kg dose of oral or a 0.5 mg/kg dose of IV meloxicam in a randomized cross-over design with an 11 day washout period between treatments. Plasma samples collected up to 96 hours post-administration were analyzed by high pressure liquid chromatography and mass spectrometry detection (HPLC-MS) followed by non-compartmental pharmacokinetic analysis.ResultsA mean peak plasma concentration (CMAX) of 1.314 μg/mL (Range: 0.826 – 1.776 μg/mL) was recorded at 21.4 hours (Range: 12.0 – 24.0 hours) with a half-life (T ½ λz) of 22.7 hours (Range: 18.0 – 30.8 hours) after oral meloxicam administration. In comparison, a half-life (T ½ λz) of 17.4 hours (Range: 16.2 – 20.7 hours) was demonstrated with IV meloxicam administration. The oral bioavailability (F) of meloxicam (dose normalized) was 76% (Range: 48 – 92%). No adverse effects associated with either treatment modality were observed in the llamas.ConclusionsThe mean bioavailability (F) of oral meloxicam was 76% indicating a high degree of gastrointestinal absorption. Plasma meloxicam concentrations >0.2 μg/mL were maintained for up to 72 h after oral administration; >0.2 μg/mL is considered to be the concentration of meloxicam required for analgesic effects in other species such as the horse. These data suggest that a single dosage of oral meloxicam at 1 mg/kg could potentially maintain therapeutic concentrations in plasma for up to 3 days in adult llamas.

Perspectives on the treatment of claw lesions in cattle

Lameness is a leading cause of welfare and culling issues in cattle, with claw lesions accounting for the majority of these issues. Although the treatment of claw lesions in cattle is a daily activity for hoof trimmers, veterinarians, and livestock producers, there is surprisingly little information in the peer-reviewed literature on which to base strong evidence-based conclusions. As a consequence, many treatment modalities used are empirical and, in some cases, may be counterproductive to rapid lesion healing. Furthermore, many of these empirical treatment modalities fail to fully consider the underlying pathogenesis of the disease process and the implications that it has on lesion healing. For example, sole ulcers are largely a consequence of metabolic disorders and mechanical overloading. Therapeutic interventions that fail to address the weight-bearing issues are unlikely to be successful. Likewise, white line disease is believed to be predisposed by rumen acidosis and laminitis, and interventions need to include in them appropriate measures to prevent further cases through nutritional management. The goal of this review paper is to review the pathogenesis of claw lesions in the context of the published literature and allow the reader to arrive at rational treatment interventions based on the best available information. The use of an orthopedic block applied to the healthy claw of a lame foot, judicious use of bandage or wrap, careful selection of parenteral or topical therapy, and a treatment protocol to manage pain and promote recovery are key components of responsible management of lameness disorders in cattle.

RNAseq Reveals Complex Response of Campylobacter jejuni to Ovine Bile and In vivo Gallbladder Environment

Colonization of the gallbladder by enteric pathogens such as Salmonella typhi, Listeria monocytogenes, and Campylobacter jejuni is thought to play a key role in transmission and persistence of these important zoonotic agents; however, little is known about the molecular mechanisms that allow for bacterial survival within this harsh environment. Recently, a highly virulent C. jejuni sheep abortion (SA) clone represented by the clinical isolate IA3902 has emerged as the dominant cause for sheep abortion in the United States. Previous studies have indicated that the C. jejuni clone SA can frequently be isolated from the gallbladders of otherwise healthy sheep, suggesting that the gallbladder may serve as an important reservoir for infection. To begin to understand the molecular mechanisms associated with survival in the host gallbladder, C. jejuni IA3902 was exposed for up to 24 h to both the natural ovine host in vivo gallbladder environment, as well as ovine bile in vitro. Following exposure, total RNA was isolated from the bile and high throughput deep sequencing of strand specific rRNA-depleted total RNA was used to characterize the transcriptome of IA3902 under these conditions. Our results demonstrated for the first time the complete transcriptome of C. jejuni IA3902 during exposure to an important host environment, the sheep gallbladder. Exposure to the host environment as compared to in vitro bile alone provided a more robust picture of the complexity of gene regulation required for survival in the host gallbladder. A subset of genes including a large number of protein coding genes as well as seven previously identified non-coding RNAs were confirmed to be differentially expressed within our data, suggesting that they may play a key role in adaptation upon exposure to these conditions. This research provides valuable insights into the molecular mechanisms that may be utilized by C. jejuni IA3902 to colonize and survive within the inhospitable gallbladder environment.

Surgical correction of angular and torsional metatarsal deformity with cylindrical osteotomy and locking compression plates in a calf.

OBJECTIVE To report successful surgical correction of concurrent angular and torsional metatarsal deformities in a calf using a cylindrical osteotomy and locking compression plate (LCP) technology. STUDY DESIGN Case report. ANIMALS A 10-week-old composite bull calf. METHODS Using Paleys principles of angular limb deformity correction, a cylindrical osteotomy was performed to concurrently correct varus deformity and external torsion of the metatarsus. The limb was aligned and stabilized using two 3.5 mm broad LCP with locking head screws. RESULTS The calf was immediately weight bearing after surgery and did not experience any postoperative complications. Follow-up radiographs 5 months postoperatively revealed complete osteotomy healing and remodeling. The limb was in good alignment, the calf was fully weight bearing, and client satisfaction was very high. Telephone follow-up with the owner 16 months after surgery revealed continued full use of the operated limb and the bull was being used in a pasture breeding program. CONCLUSIONS Cylindrical osteotomy with LCP stabilization can provide a favorable outcome in angular and torsional metatarsal deformity correction in cattle.Objective To report successful surgical correction of concurrent angular and torsional metatarsal deformities in a calf using a cylindrical osteotomy and locking compression plate (LCP) technology. Study Design Case report. Animals A 10-week-old composite bull calf. Methods Using Paleys principles of angular limb deformity correction, a cylindrical osteotomy was performed to concurrently correct varus deformity and external torsion of the metatarsus. The limb was aligned and stabilized using two 3.5 mm broad LCP with locking head screws. Results The calf was immediately weight bearing after surgery and did not experience any postoperative complications. Follow-up radiographs 5 months postoperatively revealed complete osteotomy healing and remodeling. The limb was in good alignment, the calf was fully weight bearing, and client satisfaction was very high. Telephone follow-up with the owner 16 months after surgery revealed continued full use of the operated limb and the bull was being used in a pasture breeding program. Conclusions Cylindrical osteotomy with LCP stabilization can provide a favorable outcome in angular and torsional metatarsal deformity correction in cattle.

Identification of Lamanema chavezi Becklund 1963 infection in a llama (Lama glama) in the United States

Infection with Lamanema chavezi, a parasitic nematode of New World camelids, was diagnosed by examination of feces and formalin-fixed liver from a 14-month-old female llama (Lama glama) that died after a 6-week illness. Infection with L. chavezi was initially suspected when a granuloma containing an unidentified nematode was detected microscopically in the hepatic parenchyma from a necropsy specimen. The subsequent diagnosis of L. chavezi infection was based on the morphologic features of 2 immature nematodes dissected from individual hepatic granulomas, characteristics of eggs detected in feces of the llama by centrifugal flotation in sugar solution (specific gravity: 1.30), development of third-stage larvae within the eggs after incubation of the llama feces at room temperature for ≥30 days, and the morphology of third-stage larvae released from the embryonated eggs. Collectively, these findings indicate that the llama, born and raised in Oregon, harbored an autochthonous L. chavezi infection. Eggs identified as L. chavezi were also detected by centrifugal flotation of pelleted feces from 3 of 7 herd mates of the llama indicating this parasite is endemic in the Oregon herd. The findings reported herein serve to alert diagnosticians and veterinary practitioners to the occurrence of L. chavezi in New World camelids in the United States and describe diagnostic features of this potential pathogen.

Effects of industrial polystyrene foam insulation pads on the center of pressure and load distribution in the forefeet of clinically normal horses

OBJECTIVE To evaluate the ability of industrial polystyrene foam insulation pads to redistribute loads placed on clinically normal weight-bearing structures of the foot and shift the location of the center of pressure palmarly in horses. ANIMALS 25 nonlame mature horses. PROCEDURES Both forefeet from each horse were evaluated. Center of pressure data and solar load distribution patterns were recorded during a 5-second trial by use of a commercial pressure measurement system prior to placement of foam sole support and at 0, 6, 12, 24, and 48 hours after placement. Total contact surface area, contact pressure, peak contact pressure, and center of pressure positions were compared by use of a linear mixed model with repeated measurements. RESULTS Total contact surface area was increased significantly at all time points, whereas contact pressure and peak contact pressure were significantly decreased at all time points following application of foam sole supports. Immediately following application of sole support, the position of the center of pressure was significantly moved cranially. However, by 48 hours, the center of pressure was significantly positioned more palmarly than prior to application of the foam supports. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the use of foam sole supports may be an effective, economical, and immediate treatment for acute laminitis.

Efficacy of Teaching the Gambee Suture Pattern Using Simulated Small Intestine versus Cadaveric Small Intestine

OBJECTIVE To determine if instruction using simulated small intestine (SSI) is as effective as using cadaveric small intestine to teach the Gambee suture pattern to second year veterinary students. STUDY DESIGN Prospective, randomized, blinded study. SAMPLE POPULATION Second year veterinary students (n=59). METHODS Students were randomly assigned to groups using SSI or equine cadaver small intestine (CSI) to learn the Gambee suture pattern. The same educator, an experienced surgical instructor, instructed all students. Instruction consisted of verbal description of the technique with a schematic diagram followed by a demonstration. Students then practiced the technique with supervision and verbal feedback. One week later, 3 board certified surgeons experienced in surgical instruction evaluated each student suturing equine CSI and scored them using a rubric developed and validated for surgical skills assessment. RESULTS Fifty-nine students were enrolled (4 students were absent for the lab during which the assessment was performed; 55 students were available for evaluation). Of the 55 students evaluated, 26 were in the SSI group and 29 were in the CSI group. There was no significant difference between CSI and SSI groups in ability to perform the Gambee suture pattern using equine CSI 1 week following training. CONCLUSION SSI is as effective as equine cadaveric small intestine tissue to teach the Gambee suture pattern to second year veterinary students. If cadaver tissue is unavailable or undesirable, SSI could be used to instruct suture placement techniques.