Pain Management in Small Ruminants and Camelids: Analgesic Agents.

Small ruminants are increasing in popularity as both production and companion animals in the United States. Among sheep, goats, and camelids, there are many disease processes and management techniques that have the potential to result in painful or noxious stimuli. In these species, many medications and therapeutic techniques can be used to reduce or eliminate the long-term consequences of pain. This review focuses on the commonly used medications available for pain management of small ruminants and discusses the benefits and negative aspects of their use.

Pain Management in Small Ruminants and Camelids: Applications and Strategies.

Small ruminants are increasing in popularity as production and companion animals in the United States, and among sheep, goats, and camelids there are many disease processes and management techniques that have the potential to result in painful or noxious stimuli. In these species, many medications and therapeutic techniques can be used to reduce or eliminate the long-term consequences of pain. In this second portion of the review, we focus on the application of pain management in these species. These strategies include mono- and multimodal and the use of precision pain management, such as epidural drug administration, regional perfusions, and transdermal applications.

In vitro Elution of Penicillin, Ampicillin, Tetracycline, Tulathromycin, and Florfenicol From Plaster of Paris Beads.

The objectives of this study were to report a recipe for making antibiotic impregnated Plaster of Paris (AI-PoP) beads using penicillin, ampicillin, tetracycline, tulathromycin, and florfenicol and to determine the in vitro elution rates of those antibiotics in the beads. The AI-PoP beads were made using Plaster of Paris powder, antibiotic, and water, cured for 24 h, sterilized by ethylene oxide, and stored up to 5 months before testing. For each antibiotic, 20 beads were combined with bovine serum in sterile tubes and incubated at 37°C on a rocker. Serum was replaced at intervals over the 14 days study period, and antibiotic concentrations were determined by high pressure liquid chromatography with mass spectrometry. Separately, in a proof-of-concept study, the growth of E. coli and T. pyogenes in eluent from 10 beads for each antibiotic was quantified by flow cytometry. Antibiotic was detected in AI-PoP bead eluent for 14 days for all but the ampicillin beads, for which antibiotic was detected for 8 days. The concentration of antibiotic in eluent was greater than the minimum inhibitory concentration (MIC) of tested bacteria for the entire study period for penicillin, tetracycline, tulathromycin, and florfenicol. The concentration of ampicillin remained greater than the MIC of E. coli for 4 days and T. pyogenes for 6 days. The colony forming units (CFU)/ml of live E. coli and T. pyogenes was reduced over a 72-h period by 1-3 log10 CFU, with the exception of tetracycline, which reduced CFU/ml of T. pyogenes by

Clinical presentations and antimicrobial susceptibilities of Corynebacterium cystitidis associated with renal disease in four beef cattle.

BACKGROUND: Renal disease caused by Corynebacterium cystitidis in beef cattle may be misclassified as Corynebacterium renale, and limited information about C. cystitidis infections in beef cattle currently is available. OBJECTIVE: To describe clinical presentation, diagnosis, minimum inhibitory concentrations (MICs), and outcome of renal disease caused by C. cystitidis in beef cattle. METHODS: Retrospective case series. ANIMALS: Four client-owned beef cattle. RESULTS: All affected cattle had anorexia as a primary complaint. Of the 3 that had ante-mortem diagnostic tests performed, all had pyelonephritis based on azotemia in combination with urinalysis and ultrasonographic findings. Cultures yielded C. cystitidis which was identified by biochemical testing, 16S RNA sequencing, and mass spectrometry. All affected cattle deteriorated despite aggressive treatment, indicating that C. cystitidis infections in beef cattle may carry a poor prognosis. Bacterial isolates collected from the 4 cattle showed similarities in MICs for ampicillin, florfenicol, gentamicin, neomycin, sulfadimethoxine, trimethoprim sulfonamide, and tylosin. CONCLUSIONS AND CLINICAL IMPORTANCE: Corynebacterium cystitidis should be considered in the differential diagnosis of cattle with renal disease. Definitive diagnosis of C. cystitidis as compared to C. renale may be challenging.

Histopathology and Spatial Distribution of Putative Growth Factors in Relation to Bacterial Localization of Campylobacter jejuni Within the Ovine Gallbladder.

Campylobacter jejuni is an important zoonotic pathogen that is the leading cause of both human foodborne bacterial gastroenteritis worldwide and ovine abortion in the United States. Previous studies have demonstrated that the gallbladder of ruminants is often positive on culture for Campylobacter sp., suggesting that this environment may serve as a chronic nidus of infection for maintenance of disease within populations. The objective of this study was to determine if previously identified putative growth promoting factors of C. jejuni are present within the gallbladder mucosa of sheep and to evaluate for bacterial co-localization of C. jejuni with these compounds following experimental inoculation. Direct gallbladder inoculation with C. jejuni sheep abortion (SA) clone clinical isolate IA3902 followed by immunohistochemical analysis and scanning electron microscopy allowed for identification of C. jejuni at the gallbladder mucosal surface and within the gallbladder submucosal glands. Histochemistry identified several putative Campylobacter growth promoting factors including neutral and acid mucins as well as L-fucose to be present both on the mucosal surface as well as in the gallbladder submucosal glands. In summary, following experimental inoculation of the ovine gallbladder, C. jejuni IA3902 was identified in direct contact with the gallbladder mucosal surface and deep mucosal glands in the same location as several putative growth promoting factors. This suggests the yet to be tested hypothesis that under natural conditions of infection, the gallbladder submucosal glands have the potential to provide a protected niche for chronic carriage of C. jejuni in animal hosts.

Surgical intervention for vertebral osteomyelitis in a calf.

OBJECTIVE: To report the surgical treatment and outcome of a non-ambulatory calf with cervical vertebral ostoeomyelitis. STUDY DESIGN: Clinical report. SAMPLE POPULATION: One 3.5-month-old female mixed-breed calf with tetraparesis of 3 months duration. METHODS: After computed tomography-guided bone biopsy, a bacterial osteolytic lesion within the body of the fourth cervical vertebrae (C4) and resultant pathologic compression fracture clinically resulting in full tetraparesis was diagnosed in the calf. Culture results from the lesion within C4 confirmed a diagnosis of Trueperella pyogenes. RESULTS: Poor response to medical management justified surgical debridment of the lesion in C4 and subsequent stabilization of the cervical vertebral column. A three-part procedure was performed including (1) debridement of the C4, (2) bilateral ventral vertebral stabilization from C3 to C5, and (3) placement of ampicillin-impregnated plaster of Paris beads within the body of C4. With postoperative physical rehabilitation, the calf regained full ambulatory function. At 1-month follow-up, the calf remained ambulatory with mild proprioceptive ataxia and no evidence of implant failure. At annual recheck, the calf had gained 208 kg and remained fully ambulatory with no residual neurologic deficits. CONCLUSION: Surgical intervention and use of antibiotic-impregnated implants offered a viable alternative to long-term medical management of vertebral osteomyelitis in the calf reported here. CLINICAL SIGNIFICANCE: This case identifies surgical intervention as a potential means for improving outcomes in a historically fatal condition of production animals.

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.

Surgery of the Sinuses and Eyes.

Conditions of the head requiring surgery in cattle are not uncommon when considering the incidence of conditions such as ocular squamous cell carcinoma and requests for surgical dehorning. Surgery involving the eyes in cattle is relatively common, whereas surgery of the paranasal sinuses is less common. Generally speaking, however, surgery for conditions of the head tend to have a more favorable prognosis when there is early intervention.

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.

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.

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.

The effects of topical oxygen therapy on equine distal limb dermal wound healing.

Topical oxygen therapy (TOT) has been used in human medicine to promote healing in chronic wounds. To test the efficacy and safety of TOT in horses, an experimental wound model was created by making 1 standardized dermal wound on each limb of 4 healthy horses (n = 16). Each wound was fitted with an oxygen delivery cannula and covered with a bandage. One limb of each front and hind pair was randomly assigned to the treatment group (fitted with an oxygen concentrator device), with the contralateral limb assigned to the control group (no device). Wound area, epithelial area, and contraction were measured every 3 to 4 d. Biopsy samples and culture swabs were taken on days 16 and 32 to evaluate angiogenesis, fibroplasia, epithelial hyperplasia, inflammation and bacterial growth. Mean healing time in treated wounds (45 d, range: 38 to 52 d) was not significantly different from that in the paired control wounds (50 d, range: 38 to 62 d). Topical oxygen therapy had little effect on dermal wound healing in this experimental wound model in healthy horses.

Effets de la thérapie à l'oxygène topique sur la guérison des blessures cutanées des membres distaux équins. La thérapie à l'oxygène topique (TOT) a été utilisée en médecine humaine pour traiter les blessures chroniques. Afin de tester l'efficacité et l'innocuité de la TOT chez les chevaux, un modèle de blessure expérimental a été créé en pratiquant une blessure cutanée normalisée chez 4 chevaux en santé (n = 16). Chaque blessure a été équipée d'une canule de distribution d'oxygène et couverte d'un pansement. Une jambe avant et une jambe arrière ont été assignées au hasard au groupe de traitement (équipée d'un dispositif de concentration d'oxygène) et la jambe controlatérale a été assignée au groupe témoin (aucun dispositif). La région de la blessure, la région épithéliale et les contractions ont été mesurées tous les 3 ou 4 jours. Des biopsies et des écouvillons pour culture bactérienne ont été prélevés aux jours 16 et 32 afin d'évaluer l' angiogenèse, la fibroplasie, l'hyperplasie épithéliale, l'inflammation et la croissance bactérienne. La durée moyenne de guérison des blessures traitées (45 jours, écart : de 38 à 52 jours) n'était pas significativement différente de celle des blessures témoins (50 jours, écart : de 38 à 62 jours). La thérapie à l'oxygène topique a eu peu d'effet sur la guérison des blessures dans ce modèle de blessure expérimentale chez des chevaux en santé.(Traduit par Isabelle Vallières).

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 Paley's 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.

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.

Bioavailability and pharmacokinetics of oral meloxicam in llamas.

BACKGROUND: South 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. RESULTS: A 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. CONCLUSIONS: The 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.

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.