Veterinary Medicine Commons^™

Regenerative Medicine For Tendon/Ligament Injuries: De Novo Equine Tendon/Ligament Neotissue Generation And Application, Takashi Taguchi

LSU Doctoral Dissertations

Tendon and ligament injuries are debilitating conditions across species. Poor regenerative capacities of these tissues limit restoration of original functions. The first study evaluated the effect of cellular administration on tendon/ligament injuries in horses using meta-analysis. The cellular administration was effective in restoring ultrasonographic echogenicity and increasing vascularity during early phase of healing. Additionally, it improved microstructural organization of healed tissue in terms of cellularity and fiber alignment. However, the study did not support its use for increasing rate of return to performance, expression/deposition of tendon-specific genes/proteins, or mechanical properties.

The findings led to the second study that engineered implantable …

Effects Of High-Speed Training On Messenger Rna Expression In Two-Year-Old Thoroughbred Racehorses, Mackenzie Grace Johnson

Theses and Dissertations--Veterinary Science

Accumulating high-speed exercise has been identified as a significant risk factor for catastrophic injuries in racing Thoroughbreds. Injuries, regardless of severity, are a main cause of withdrawal from the racing industry, raising animal welfare concerns and resulting in significant economic losses. While most of the current literature focuses on catastrophic injuries incurred during racing rather than training, the present study aims to help fill this gap as well as discuss the associated risk factors. The evaluation of messenger RNA (mRNA) expression changes provides an efficient and straightforward approach to identifying horses at risk for catastrophic injury. While alternative injury risk …

Intra-Articular Buprenorphine In Horses, Gabriel Castro-Cuellar Dr

LSU Master's Theses

Opioid drugs have the potential of provide local analgesia in inflamed joints. To date, morphine is the only opioid that has been tested for intra-articular (IA) administration in horses. Having an alternative drug, other than morphine, could widen the therapeutic options, particularly in cases of drug shortages or inaccessibility to specific drugs. The work presented in this dissertation reports the cytotoxic effects of buprenorphine on cultured equine chondrocytes, and the pharmacokinetic, pharmacodynamic and analgesic effects, of IA administered buprenorphine in horses with experimentally induced synovitis.

To evaluate the potential cytotoxic effects on equine cartilage, chondrocytes were obtained from normal equine …

Maturation Of Equine Proximal Sesamoid Bones In Thoroughbred Horses, Angela Maria Mangine

Theses and Dissertations--Veterinary Science

Proximal sesamoid bone (PSB) injuries account for approximately 50% of all fatal catastrophic musculoskeletal injuries in Thoroughbred racehorses. In addition, PSB fractures are not uncommon in Thoroughbred foals and yearlings as a result of energetic or intense free exercise. The ability to interpret some PSB pathology assessments, however, is more difficult given the limited information published on the normal development and maturation of these paired sesamoid bones. In addition, the level of normal variation in PSB morphological and structural parameters within the Thoroughbred population as a function of age, body size, gender, and inter-animal variation are not well documented, complicating …

Muscle Mass And Immune Function In The Senior Horse, Alisa Christina Herbst

Theses and Dissertations--Veterinary Science

Senior horses (≥ 15 years) represent up to one-third of the global equine population, and the proportion of old horses (≥ 20 years) in the U.S. has been steadily increasing. Aging is associated with a loss of skeletal muscle mass in horses, and while age-related muscle loss is comparingly well characterized in humans, little is currently known concerning underlying mechanisms, adverse outcomes, or the prevalence of low muscle mass in senior horses. One factor proposed to play a role in the development of age-related muscle atrophy in humans is inflamm-aging, a low-grade inflammation that affects elderly people and that has …

Structural Adaptation Of Equine Proximal Sesamoid Bones To High-Speed Exercise, Kathryn Mary Babiarz

Theses and Dissertations--Veterinary Science

Proximal sesamoid bone (PSB) fractures are one of the most commonly reported catastrophic musculoskeletal injuries (CMI) in Thoroughbred racing. Despite the seriousness of these injuries, an understanding of the structural changes that occur normally within PSBs in response to the biomechanical forces of high-speed exercise and how they relate to pathological events leading to fracture remain limited. To address this critical knowledge gap, PSBs from Thoroughbred horses were analyzed with both computed tomography (CT) and microcomputed tomography (µCT) to assess their morphological and structural parameters. Comparisons were made using samples from the left and right forelimbs of Thoroughbreds of both …

The Effect Of Hay Net Use On Cribbing Horses, Lauren Wesolowski

Undergraduate Honors Thesis Projects

Cribbing is a stereotypic behavior observed in horses, wherein the animal grasps a solid object with its front incisors and contracts its neck muscles to suck in air through its mouth, resulting in an audible grunt. Stereotypic behaviors such as cribbing are thought to be done in response to stress or insufficient stimulus in an animal’s living environment. Slow feeding hay nets can increase the amount of time horses spend eating daily hay rations. This research aims to use slow feeding hay nets to create a feeding process that is closer to natural grazing behavior and provide more stimulation for …

Comparative Chondrogenesis Of Interzone And Anlagen Cells In Equine Skeletal Development, Chanhee Mok

Theses and Dissertations--Veterinary Science

At the presumptive sites of future synovial joints during mammalian skeletogenesis, articular cartilage develops from interzone located between the cartilaginous anlagen of bones. Thus, two types of cartilaginous tissues differentiate in close proximity. While anlagen cartilage is transient, progressing through endochondral ossification to form bones, articular cartilage is stable and functions throughout life to facilitate both low friction movement and load distribution. Despite important life-long functional properties, articular cartilage has a very limited intrinsic ability to repair structural defects. On the other hand, structural lesions in bones generally heal well by forming a cartilaginous callus and recapitulating endochondral ossification to …

Donor Age Effects On The Proliferative And Chondrogenic/Osteogenic Differentiation Performance Of Equine Bone Marrow- And Adipose Tissue Derived Mesenchymal Stem Cells In Culture, Jasmin Bagge

Theses and Dissertations--Veterinary Science

Orthopedic injuries are a major cause of lameness and morbidity in horses. Bone marrow (BM)- and adipose tissue (AT) derived mesenchymal stem cells (MSCs) have shown potential to facilitate the repair of orthopedic injuries and are being used increasingly in veterinary clinics. Presently, the use of MSCs as a therapy for equine patients is most commonly applied as autologous transplants, using BM- and AT-MSCs harvested from the patient shortly after the time of injury. Cell-based therapies are therefore delayed to enable primary cell numbers to be expanded in culture. Of concern, however, are human and rodent studies that have shown …

Analysis Of Humoral Immune Responses In Horses With Equine Protozoal Myeloencephalitis, Catherine-Jane Angwin

Theses and Dissertations--Veterinary Science

Equine protozoal myeloencephalitis (EPM), caused by the protozoan parasite Sarcocystis neurona, is one of the most important neurological diseases of horses in the Americas. While seroprevalence of S. neurona in horses is high, clinical manifestation of EPM occurs in less than 1% of infected horses. Factors governing the occurrence and severity of EPM are largely unknown, although horse immunity might play an important role in clinical outcome. We hypothesize that EPM occurs due to an aberrant immune response, which will be discernable in the equine IgG subisotypes a, b, and (T) that recognize S. neurona in infected diseased horses versus …

Lymphocyte-Mediated Inflamm-Aging In The Horse, Melissa Hope Siard

Theses and Dissertations--Veterinary Science

Senior horses (≥20 years) exhibit inflamm-aging, or chronic, low-grade inflammation that occurs systemically with aging, similarly to humans. Inflamm-aging has previously been characterized in the horse in circulation as well as specifically being mediated by lymphocytes and monocytes. In humans, inflamm-aging has been associated with increased morbidity and mortality. However, in the horse, relatively little about inflamm-aging is known regarding clinical effects or factors influencing severity. The contribution of lymphocytes to inflamm-aging of senior horses was examined, specifically through determining the relationships of inflamm-aging with various other health parameters, effects of seasonality, and the extent to which inflamm-aging can be …

The Effect Of Whole Body Vibration On Equine Hoof Growth, Sharlee Lowe

Undergraduate Honors Thesis Projects

Equine foot pain can be a result of many conditions and disease processes, all of which lead to a loss of function in the horse. When the horse loads the foot, pressure applied to the frog translates to the digital cushion and lateral cartilages, compressing the blood vessels, perfusing the area, and circulating blood back up the leg; this constant flow of blood stimulates growth of the hoof wall. Whole body vibration plates are thought to result in rapid muscle contractions and subsequently, increased circulation through the foot. An increase in hoof growth could prove whole body vibration beneficial as …

Differential Gene Expression In Equine Cartilaginous Tissues And Induced Chondrocytes, Emma N. Adam

Theses and Dissertations--Veterinary Science

Degenerative joint disease, or osteoarthritis, is a major cause of lameness and morbidity in horses, humans, and dogs. There are no truly satisfactory cures for this widespread problem and current treatments all have limitations or unwanted side effects.

New cell-based strategies to repair joint surface lesions have generated a high level of interest, but have yet to achieve the full restoration of articular cartilage structure and function. Currently used therapy cells include autologous chondrocytes and adult mesenchymal cells such as bone marrow derived cells and adipose derived cells. Unfortunately, the resultant repair tissue is biomechanically inferior fibrocartilage. A critical gap …

Differentiation Of Equine Mesenchymal Stromal Cells Into Cells Of Neural Lineage And Their Application Into A Novel Model For Acute Peripheral Nerve Injury In The Horse, Claudia Cruz

Masters Theses

Studies have shown that mesenchymal stromal cells (MSCs) are able to differentiate into extra-mesodermal lineages, including neurons. Positive outcomes were obtained after transplantation of neurally-induced MSCs in rats, rabbits and guinea pigs after nerve injury, but the effect of these cells is unknown in horses. Our objective was to test the ability of equine mesenchymal stromal cells to differentiate into cells of neuronal lineage, and to assess differences, if any, in morphology and protein expression. Additionally, we wanted to investigate if horse age and cell passage number contributed to the ability to achieve neural differentiation.

The first part of this …

The Roles Of Orthopaedic Pathology And Genetic Determinants In Equine Cervical Stenotic Myelopathy, Jennifer Gail Janes

Theses and Dissertations--Veterinary Science

Cervical stenotic myelopathy (CSM) is an important musculoskeletal and neurologic disease of the horse. Clinical disease occurs due to malformations of the vertebrae in the neck causing stenosis of the cervical vertebral canal and subsequent spinal cord compression. The disease is multifactorial in nature, therefore a clearer understanding of the etiology and pathogenesis of CSM will allow for improved management and therapeutic practices. This thesis examines issues of equine CSM diagnosis, skeletal tissue pathology, and inherited genetic determinants utilizing advances in biomedical imaging technologies and equine genomics. Magnetic resonance imaging (MRI) data provided a more complete assessment of the cervical …

Safety And Immunoreactivity Of A Xenogeneic Dna Plasmid Vaccine Expressing Human Tyrosinase In Tumor-Bearing Horses, Luis Miguel Lembcke Perez Prieto

Doctoral Dissertations

Melanomas are among the most common skin tumors in horses (second only to sarcoids), with prevalence rates reaching as high as 80% in adult gray horses. Despite the wide availability of measures of local control, there are currently no systemic therapies that can effectively prevent spread, or treat metastatic or locally advanced/non-resectable melanoma in horses. A form of gene immunotherapy based on a plasmid DNA construct containing a xenogeneic form of the antigen tyrosinase have been developed and optimized for targeting cancer in both humans and dogs; and have demonstrated significant immunoreactivity and clinical benefit in the treatment of melanocytic …

Determination Of Farm-Specific Lawsonia Intracellularis Seroprevalence In Central Kentucky Thoroughbreds And The Identification Of Factors Contributing To Equine Proliferative Enteropathy, Allen E. Page

Theses and Dissertations--Veterinary Science

Lawsonia intracellularis and the disease it causes in horses, equine proliferative enteropathy (EPE), is an emerging pathogen of increasing importance to the horse industry from both an economic and welfare standpoint. Long recognized as an economically important disease of swine, the hallmark of EPE is a protein-losing enteropathy, where affected horses suffer weight loss and some ultimately succumb to the disease despite aggressive treatment. There are currently no known EPE preventative measures and the epidemiology of the disease remains poorly defined. While EPE is a sporadic disease affecting less than 25% of exposed horses, some farms experience clinical cases year …

Ingestion Of Endophyte-Infected Tall Fescue Seed Induces Peripheral Vasoconstriction But Does Not Affect Cyclicity In Non-Pregnant Mares, And A Population Of Biogenic Amine Receptors Relative To Vasoconstriction Is Identified, Daniel Andrew Hestad

Theses and Dissertations--Veterinary Science

Three experiments were conducted to explore the effect of fescue toxicosis on vasoconstriction and various parameters of the estrous cycle. In the experiment of Chapter 3, a 2x2 crossover experimental design with repeated measures was implemented to test whether the ingestion of endophyte-infected tall fescue seed would alter blood hormone concentrations of prolactin, progesterone, and estradiol, interovulatory intervals, and corpus luteum blood flow. Also, Doppler ultrasonography was used to assess whether palmar artery and palmar vein lumen diameter, area, circumference, and resistivity index could be altered by the ingestion of endophyte-infected tall fescue seed. Ingestion of endophyte-infected tall fescue seed …

The Role Of Systemic Inflammation In The Development Of Equine Laminitis, Elizabeth Maryrose Tadros

Doctoral Dissertations

Laminitis is a crippling disease of horses that can result in chronic lameness and debilitation, and sometimes warrants euthanasia. It is a complication of inflammatory conditions such as gastrointestinal disease, and also occurs in obese, insulin-resistant horses with Equine Metabolic Syndrome (EMS). Inflammation and insulin resistance are risk factors for laminitis, and these mechanisms might converge to induce laminitis in susceptible animals.

Systemic inflammation is often attributed to endotoxemia, although circulating endotoxin concentrations are not commonly measured in the clinical setting. Although a theoretic basis exists for endotoxemia in the pathogenesis of laminitis, administration of endotoxin alone does …

Development Of A Robust Genetic Test For Hyperkalemic Periodic Paralysis (Hypp) In Quarter Horses, Samantha Traver

Honors Theses

A single nucleotide substitution in a region of the skeletal muscle sodium channel gene (SCN4A) is known to cause an equine genetic disorder known as Hyperkalemic Periodic Paralysis (HYPP). The clinical effects of this disorder range from little or no symptoms to frequent episodes of muscle tremors, weakness, and/or complete collapse. Oligonucleotide primer pairs were designed for both the wild type and mutant alleles of the SCN4A gene for use in Amplification Refractory Mutation System-PCR (ARMS-PCR). These primers were tested with genomic DNA isolated from whole blood, saliva swabs, and hair of individual horses. It was determined that horse hair …

Genetic Immunization In The Horse: The Potential For Enhanced Immune Responses With Deacylated Polyethyleneimine (Pei) And Immunostimulatory Cytokines As Vaccine Adjuvants, Deborah Lee Even

Theses and Dissertations--Veterinary Science

DNA vaccines in larger animals, such as horses, are generally less effective and elicit significantly weaker immune responses, than in small animal model systems. To provide optimal protection against pathogenic microorganisms, the induction of both humoral and cellular immune responses from DNA vaccination may be necessary. One limitation to DNA immunization in the horse is the difficulty in generating high levels of antigen-specific antibody and CTL responses. Previous work in the laboratory has demonstrated that expression constructs containing native sequences encoding the surface unit (SU) envelope glycoprotein (pCiSU) of the Equine Infectious Anemia Virus (EIAV) are ineffective at stimulating immune …

Diagnosis And Management Of Horses With Equine Metabolic Syndrome (Ems), Kelly Ann Chameroy

Doctoral Dissertations

In horses, a painful and often debilitating disease known as laminitis can result in impaired function and, in severe cases, euthanasia. Equine Metabolic Syndrome (EMS) is a syndrome in horses that results in development of laminitis and is characterized by the presence of general and/or regional adiposity (“cresty neck”), aberrations in blood lipid concentrations, insulin resistance (IR) and/ or hyperinsulinemia. Therapies have focused on improving the state of obesity and insulin resistance with the goal of diminishing the likelihood of laminitis development. A definitive cause for laminitis has not been established, but hyperinsulinemia and IR are likely candidates as experimental …

Effects Of Clenbuterol On Skeletal And Cardiac Muscle In Horses, Jessica Thompson

LSU Master's Theses

Clenbuterol is a commonly prescribed β2-adrenergic agonist approved for veterinary use as a bronchodilator in horses with reactive and obstructive airway disease. Potential for abuse of this drug in the horse industry is substantial, due to the perceptions that clenbuterol increases performance and lean muscle mass. Although anabolic effects have been confirmed in multiple species, recent studies into the effects of clenbuterol in exercising horses suggest that clenbuterol doses within therapeutic ranges negatively impact aerobic capacity and cardiac function. Results of studies in murine models demonstrate that clenbuterol directly induces skeletal and cardiac muscle cell death at high doses. Three …

Matrix Metalloproteinases In The Equine Systemic Inflammatory Response: Implications For Equine Laminitis, Lee Ann Fugler

LSU Doctoral Dissertations

Laminitis is a crippling and often life-threatening disease of the equine foot. Soft tissue damage characteristic of this disease has been associated with increased MMP activity. Therefore, it seems likely that MMPIs could be potential therapeutic agents for laminitis. Further characterization of equine MMPs and evaluation of the effectiveness of MMPIs in the horse are needed. Equine MMP-9 was harvested from neutrophils, purified by affinity chromatography, and evaluated using western blotting and gelatin zymography. The Biotrak MMP-9 Activity Assay was evaluated for use with equine samples using equine neutrophil MMP-9 as a standard, and was determined to have insufficient sensitivity …

Characterization And Comparison Of Cell Frequency, Growth, And Multipotential Differentiation Of Adult Mesenchymal Stromal Cells Derived From Equine Bone Marrow And Adipose Tissue, Martin Andreas Vidal

LSU Doctoral Dissertations

Equine bone marrow-derived mesenchymal stromal cells (MSCs) and adipose tissue-derived stromal cells (ASCs) were compared for frequency within their respective tissues, cell doubling characteristics and differentiation multipotential in culture based on histochemical staining and compositional analysis. Equine MSCs and ASCs from young adult horses were harvested and isolated from sternal bone marrow and supragluteal subcutaneous adipose tissue, respectively, and grown up to passage 10 (P10) to determine cell doubling characteristics. Limit dilution assays were performed on primary and passaged (P2, P4) MSCs and ASCs to determine the frequency of colony forming units with a fibroblastic phenotype (CFU-F), and the frequency …

The Relationship Between Pro-Inflammatory Cytokines, Prostaglandins, And Fetal Hypothalamic-Pituitary-Adrenal Axis Activation In Mares With Infective Pre-Term Delivery, Sara K. Lyle

LSU Doctoral Dissertations

Ascending placentitis is a significant cause of abortions, stillbirths, and perinatal loss in horses. A technique for laparoscopic-guided catheterization of the allantoic space was developed and utilized in an experimental model of streptococcal infective pre-term delivery in pony mares. Mares received either 1 x 107 CFU live S. zooepidemicus (n=3), 5.1 x 108 CFU live S. zooepidemicus (n=1), 1 x 107 heat-killed S. zooepidemicus (n=3), 1 mL sterile PBS (n=3). Sham control mares did not receive a transcervical inoculation (n=3). One mare not instrumented with an allantoic catheter received 5.1 x 108 CFU live S. zooepidemicus. Mares with spontaneous abortion …

Characterizing Salmonella Fecal Shedding Among Racehorses In Louisiana, Anna Marie Chapman

LSU Master's Theses

Salmonella is an important intestinal pathogen in horses capable of infecting populations without demonstrating clinical illness. This study was performed to determine the prevalence of Salmonella fecal shedding among racehorses in Louisiana. Three serial fecal samples were collected from 429 Thoroughbred horses housed at four racetracks. Feces were tested for Salmonella by microbiologic culture with selective primary enrichment and delayed secondary enrichment (DSE). Samples were also evaluated for the presence of Salmonella by polymerase chain reaction (PCR) using genus-specific oligonucleotide primers. A total of 7 (1.6%) horses were positive for Salmonella by either primary bacterial culture or DSE and an …

The Effects Of Non-Focused Extracorporeal Shock Waves On Neuronal Morphology, Function And Analgesia In Horses, David Manuel Bolt

LSU Master's Theses

These studies were conducted to elucidate the regional analgesic effect that is observed clinically after treatment of orthopedic disorders with application of extracorporeal shock waves in horses. Regional analgesia after treatment with extracorporeal shock waves presents a concern because it may eliminate protective limiting mechanisms and may place equine athletes with predisposing lesions at risk of sustaining career- or life-ending injuries. Direct percutaneous application of non-focused extracorporeal shock waves to palmar digital nerves in the pastern area of horses resulted in decreased sensory nerve conduction velocities compared with untreated control nerves at 3, 7, and 35 days after treatment. Transmission …

Equine Immunity To Cyathostome Infections, Marie Alexandra Baudena

LSU Doctoral Dissertations

To study the protective responses of cyathostome-infected ponies, two challenges were performed employing animals with different histories of exposure to these parasites. The hypothesis developed and to be tested in these experiments was that ponies that had longer exposure to cyathostome contaminated pastures would express acquired resistance to infection. The assumption behind this hypothesis was that helminth-naïve ponies infected with cyathostomes would eliminate the infection using only innate immune responses. Whereas previously exposed ponies would eliminate the infection with acquired immune responses, and these would be more effective in ponies with longer exposure to cyathostomes. Thus, helminth-naïve animals would acquire …