Ex vivo biomechanical comparison of pedicle screw and rod constructs with and without interbody fusion devices for equine cervical vertebral stabilization.

Objective: To determine the biomechanical properties of pedicle screw and rod (PSR) constructs alone and with an interbody fusion device (PSRIFD) for equine ventral cervical vertebral stabilization.

Study Design: Cadaveric ex vivo biomechanical analysis.

Sample Population: A total of 14 (n = 14) adult equine cervical vertebral columns.

Interleukin-1β as an articular process joint intra-articular model induces synovitis and signs of acute neck pain in horses.

Objective: To develop and define a model of acute neck pain in an equine cervical articular process joint (APJ) using recombinant equine IL-1β (reIL-1β).

Methods: 12 horses in this experimental study received a randomly assigned, unilateral intra-articular injection of 50 ng (n = 6) or 100 ng (n = 6) of reIL-1β and saline (contralateral side as control) into the C5-to-C6 APJ. Blinded ultrasonographic, clinical, and biomechanical parameters were evaluated between 4 hours and 14 days.

Neck pain but not neurologic disease occurs more frequently in horses with transposition of the ventral lamina from C6 to C7.

Objective: To determine reasons for horses to have neck radiographs performed, the incidence of transposition of the ventral lamina of C6 onto C7 (TC67), and the final diagnoses for all horses. Our hypotheses were to find a similar incidence of TC67, as has been previously reported, and an increased incidence of neck pain and dysfunction in horses with TC67.

Animals: 135 horses.

Effect of Impact Parameters on a Unilateral Contusion Model of Spinal Cord Injury in a Virtual Population of Non-Human Primates.

Non-human primate (NHP) spinal cord injury experiments exhibit high intersubject variability in biomechanical parameters even when a consistent impact protocol is applied to each subject. Optimizing impact parameters to reduce this variability through experiments is logistically challenging in NHP studies. Finite element models provide a complimentary tool to inform experimental design without the cost and complexity of live animal studies.

The biomechanical implications of neck position in cervical contusion animal models of SCI.

Large animal contusion models of spinal cord injury are an essential precursor to developing and evaluating treatment options for human spinal cord injury. Reducing variability in these experiments has been a recent focus as it increases the sensitivity with which treatment effects can be detected while simultaneously decreasing the number of animals required in a study. Here, we conducted a detailed review to explore if head and neck positioning in a cervical contusion model of spinal cord injury could be a factor impacting the biomechanics of a spinal cord injury, and thus, the resulting outcomes.

An Unusual Cause of Femoral Nerve Paresis in a Horse: Disseminated B Cell Lymphoma With Plasmacytoid Differentiation and Direct Neuronal Invasion.

A 21-year-old Quarter Horse mare presented with a chronic, progressively worsening left pelvic limb lameness of 3 weeks duration. The initial examination identified a consistent lameness at a walk. Neurological examination showed sensory and gait abnormalities consistent with left femoral nerve dysfunction.

Rhesus macaque versus rat divergence in the corticospinal projectome.

We used viral intersectional tools to map the entire projectome of corticospinal neurons associated with fine distal forelimb control in Fischer 344 rats and rhesus macaques. In rats, we found an extraordinarily diverse set of collateral projections from corticospinal neurons to 23 different brain and spinal regions. Remarkably, the vast weighting of this "motor" projection was to sensory systems in both the brain and spinal cord, confirmed by optogenetic and transsynaptic viral intersectional tools.

Traumatic Nervous System Injury.

Mechanisms of traumatic nervous system injury to a degree are similar, but differences exist in etiology, pathophysiology, and treatment of brain, spinal cord, and peripheral nerve injury. The most common clinical abnormalities seen in the horse are abnormal level of consciousness, abnormal behavior, seizures, cranial nerve deficits, vestibular disease, tetra- and paraparesis or paraplegia, cauda equina syndrome, specific gait deficits, and muscle atrophy. Treatments are directed toward reducing inflammation and swelling, halting secondary injury, and promoting mechanisms of neuroregeneration and plasticity.

Dangerous Behavior and Intractable Axial Skeletal Pain in Performance Horses: A Possible Role for Ganglioneuritis (14 Cases; 2014-2019).

Dangerous behavior is considered an undesired trait, often attributed to poor training or bad-tempered horses. Unfortunately, horses with progressive signs of dangerous behavior are often euthanized due to concerns for rider safety and limitations in performance. However, this dangerous behavior may actually originate from chronic axial skeleton pain.

Outcomes after cervical vertebral interbody fusion using an interbody fusion device and polyaxial pedicle screw and rod construct in 10 horses (2015-2019).

Background: Further development of surgical techniques for equine cervical stabilisation is necessary to make the procedure less technically demanding, reduce complications and improve outcomes.

Objective: To describe clinical outcomes and owner reports in horses undergoing placement of an interbody fusion device and polyaxial pedicle screw and rod construct for cervical vertebral fusion in horses with cervical vertebral compressive myelopathy.

Study Design: Retrospective case series.

Equine Cervical Pain and Dysfunction: Pathology, Diagnosis and Treatment.

Interest in the cervical spine as a cause of pain or dysfunction is increasingly becoming the focus of many equine practitioners. Many affected horses are presented for poor performance, while others will present with dramatic, sometimes dangerous behavior. Understanding and distinguishing the different types of neck pain is a starting point to comprehending how the clinical presentations can vary so greatly.

Bladder and Bowel Management in Dogs With Spinal Cord Injury.

Spinal cord injury in companion dogs can lead to urinary and fecal incontinence or retention, depending on the severity, and localization of the lesion along the canine nervous system. The bladder and gastrointestinal dysfunction caused by lesions of the autonomic system can be difficult to recognize, interpret and are easily overlooked. Nevertheless, it is crucial to maintain a high degree of awareness of the impact of micturition and defecation disturbances on the animal's condition, welfare and on the owner.

Equine urinary N-acetyl-β-D-glucosaminidase assay validation and correlation with other markers of kidney injury.

Detection of equine acute kidney injury (AKI) is hindered by limited markers of early renal damage in horses. N-acetyl-β-D-glucosaminidase (NAG), a lysosomal enzyme in renal tubular epithelium released into urine during tubular insult, has shown promise for early identification of AKI in humans and other species. We validated an assay for NAG in equine urine and measured urinary NAG in 7 azotemic and 7 non-azotemic client-owned adult horses.

Chondroitinase improves anatomical and functional outcomes after primate spinal cord injury.

Inhibitory extracellular matrices form around mature neurons as perineuronal nets containing chondroitin sulfate proteoglycans that limit axonal sprouting after CNS injury. The enzyme chondroitinase (Chase) degrades inhibitory chondroitin sulfate proteoglycans and improves axonal sprouting and functional recovery after spinal cord injury in rodents. We evaluated the effects of Chase in rhesus monkeys that had undergone C7 spinal cord hemisection.

Cervical stabilization with polyaxial pedicle screw and rod construct in horses: A proof of concept study.

Objective: To evaluate safety and efficacy of a novel technique for cervical stabilization.

Study Design: In vivo experimental.

Animals: Four normal adult quarterhorse crossbreed horses (2-4 years of age, > 250 kg).

Development of an International Canine Spinal Cord Injury observational registry: a collaborative data-sharing network to optimize translational studies of SCI.

Study Design: Prospective cross-sectional cohort study.

Objectives: The canine spontaneous model of spinal cord injury (SCI) is as an important pre-clinical platform as it recapitulates key facets of human injury in a naturally occurring context. The establishment of an observational canine SCI registry constitutes a key step in performing epidemiologic studies and assessing the impact of therapeutic strategies to enhance translational research.

Restorative effects of human neural stem cell grafts on the primate spinal cord.

We grafted human spinal cord-derived neural progenitor cells (NPCs) into sites of cervical spinal cord injury in rhesus monkeys (Macaca mulatta). Under three-drug immunosuppression, grafts survived at least 9 months postinjury and expressed both neuronal and glial markers. Monkey axons regenerated into grafts and formed synapses.

Quantitative Analysis and Development of the Fore Feet of Arabian Foals from Birth to 1 Year of Age.

 The goal of this study was to quantify external and internal anatomical characteristics of the foal foot throughout the first year of age.  Digital radiographs and photographs were taken bimonthly of the forefeet of nine Arabian foals, beginning at about 2 weeks of age until 12 months of age. Sixty-eight linear and angular variables were measured using NIH (National Institutes of Health) software.

Targeting Translational Successes through CANSORT-SCI: Using Pet Dogs To Identify Effective Treatments for Spinal Cord Injury.

Translation of therapeutic interventions for spinal cord injury (SCI) from laboratory to clinic has been historically challenging, highlighting the need for robust models of injury that more closely mirror the human condition. The high prevalence of acute, naturally occurring SCI in pet dogs provides a unique opportunity to evaluate expeditiously promising interventions in a population of animals that receive diagnoses and treatment clinically in a manner similar to persons with SCI, while adhering to National Institutes of Health guidelines for scientific rigor and transparent reporting. In addition, pet dogs with chronic paralysis are often maintained long-term by their owners, offering a similarly unique population for study of chronic SCI.

Influence of hypoxia on the stemness of umbilical cord matrix-derived mesenchymal stem cells cultured on chitosan films.

Chitosan is attractive as a substrate for stem cell expansion because it improves stemness through formation of spheroids. Hypoxia has also been proposed as a strategy to enhance stemness and survival of stem cells after in vivo implantation. This study was therefore designed to evaluate the influence of hypoxia on chitosan-induced behavior of stem cells.

Objective assessment of gait in xylazine-induced ataxic horses.

Background: There is poor agreement between observers of equine neurological gait abnormalities using the modified Mayhew grading scale.

Objectives: To stimulate a dose-dependent ataxia in horses through xylazine administration and identify quantifiable relevant gait parameters.

Study Design: Balanced, randomised, 2-way crossover design.

Reactive mesothelial hyperplasia associated with chronic peritonitis in a 20-year-old Quarter horse.

A 20-year-old gelding was diagnosed with peritonitis and severe reactive mesothelial hyperplasia. Exploratory laparotomy findings were suggestive of a neoplastic etiology; however, additional diagnostics ruled this out and the horse made a full recovery. This report demonstrates the difficulty and value of differentiating between reactive and neoplastic mesothelial processes.