Approximately 4% of horses suffer from one colic episode per year. The outcome is fatal in 11% of cases. F2-isoprostanes are the "gold standard" for assessment of oxidative stress in vivo and have been used extensively to quantify lipid peroxidation in association with risk factors in various diseases in humans. Because horses with colic may have intestinal ischemia and/or inflammation characterized by oxidative stress and increased production of isoprostanes, measurement of isoprostane concentrations in colicky horses may be of clinical value. The purpose of this study was to gather preliminary data on the feasibility of using urine isoprostane concentrations as an early screening tool for the severity of colic and to determine the need for surgery. The long term goal of this investigation is to reduce the number of deaths due to colic by developing a stall-side test capable of identifying horses needing surgery as early as possible and expediting their timely referral. We hypothesized that urine isoprostanes and isoprostane metabolites would be significantly higher in horses with colic compared to normal horses and that they can be used an indicator for the need for surgical intervention. Urine samples were collected from 42 normal horses and 38 horses with colic (21 medical and 22 surgical). Urine isoprostane and isoprostane metabolite concentrations were measured by mass spectrometry and normalized by urine creatinine (Cr) concentrations. Statistical analysis was performed using a one way ANOVA (Tukey's post-hoc comparison) and a 2 sample t-test. Significance was set at P<0.05. Mean (± SD) concentrations of isoprostanes and isoprostane metabolites were significantly higher in urine samples of horses with colic (2.94 ± 1.69 ng/mg Cr and 0.31 ± 0.22 ng/mg Cr, respectively) compared to healthy horses (1.89 ± 1.39 ng/mg Cr and 0.22 ± 0.08 ng/mg Cr, respectively). Urine isoprostane metabolite concentrations were significantly higher in horses undergoing surgery (0.38 ± 0.28 ng/mg Cr) compared to healthy control horses and medically treated colic horses (0.26 ± 0.11 ng/mg Cr). Non-survivors had significantly higher mean urine isoprostane metabolite concentrations (0.47 ± 0.39 ng/mg Cr) compared to healthy control horses and surviving colic horses (0.29 ± 0.24 ng/mg Cr). Since urinary concentrations of isoprostane metabolites are increased in horses suffering from colic and in non-survivor colic horses, the measurement of urine concentrations of isoprostane metabolites may be an important prognostic indicator in equine colic. / Master of Science

This study was aimed at characterizing the apoptotic response equine small intestine subjected to experimental ischemia-reperfusion injury and determining if use of an angiotensin converting enzyme inhibitor (enalaprilat) would ameliorate the apoptotic response. It was designed to determine if mucosal epithelial cells undergo apoptosis during the ischemia phase and also examined if apoptosis is significantly exacerbated by reperfusion. It also investigated whether administration of enalaprilat decreased reperfusion injury secondary to reduced enterocyte apoptosis. Injury was induced using a low flow model of I-R. During celiotomy a single loop of jejunum was isolated and arterial flow decreased to 20% of baseline for one hour and complete occlusion for a second hour. Reperfusion was monitored for 3 hours. A control group (n=6) were not treated while the treatment group (n=6) received 0.5 mg/kg enalaprilat in 0.9% NaCl immediately following ischemia. Jejunal samples were taken prior to the induction of ischemia, immediately post-ischemia and at 1, 2 and 3 hours of reperfusion. Samples were evaluated for gross tissue pathology with standard hematoxylin and eosin staining, the presence of apoptotic cells via TUNEL staining, and gene expression of three apoptosis related genes (bax, bcl-2, p53) using qPCR. Serum enalaprilat and ACE concentrations were determined from blood samples drawn concurrent with jejunal sampling using HPLC/MS and standard HPLC. Plasma enalaprilat concentrations were comparable to previous reports in awake horses. Enalaprilat appeared to have no effect on serum ACE concentrations, however a significant spike in ACE concentration occurred in the treatment group at 1 hour of reperfusion (P=0.0001). Grade of mucosal damage was not significantly different between control and treatment groups at any time point. Subjectively apoptotic index appeared to be higher in the treatment group at end ischemia and during reperfusion. There were no changes in expression of p53 or bcl-2 in either group. Bax expression was significantly decreased (P= 0.02) in the control group at 2 hours of reperfusion. Based on our data administration of an ACE inhibitor during anesthesia in horses with an ischemic segment of intestine confers no protective benefit and may be associated with increased intestinal injury and apoptosis. Lack of expression of p53, bax and bcl-2 suggests another apoptotic mechanism in equine ischemic intestine. / Master of Science

Injuries to the equine distal limb are common and often involve synovial, tendinous and/or ligamentous structures. Historically, lacerations involving the equine digital flexor tendons carried a poor prognosis for return to athletic function due to contamination of the site at presentation, involvement of multiple anatomic structures and the need for immediate weight bearing after surgery. The need for weight bearing after surgery places strain on the tenorrhaphy site that exceeds the strength of the repair itself. Extrapolation of complex, stronger tenorrhaphy patterns from human literature and applying them to equine patients has been challenging. Human tenorrhaphy techniques initially focused on strong repairs, which are able to match or exceed the strength of tendon itself. Adhesion formation is problematic in human flexor tenorrhaphies, as most injuries occur to tendons surrounded by synovial structures. Human literature now focuses on using repairs that provide initial strength, minimal damage to intrinsic tendon architecture, and allow for early mobilization. This treatment protocol has greatly improved the functional outcome of human tenorrhaphies. Recent studies have evaluated the strength of complex tenorrhaphy patterns in equine superficial digital flexor tendons, using modifications of the Savage technique. The newly evaluated patterns are stronger than previously tested and commonly used techniques, such as the three-loop pulley (3LP). A review of tendon vasculature across species and healing characteristics of tendons highlights the importance of intrinsic tendon vasculature in the healing process. Using tenorrhaphy techniques that preserve this vasculature may improve the clinical outcome in these cases. Only one study has previously evaluated the effect of tenorrhaphy patterns on intrinsic tendon vasculature in equine superficial digital flexor tendon. This study compared perfusion of intrinsic tendon vasculature of equine superficial digital flexor tendon (SDFT) after 3LP and six-strand Savage (SSS) tenorrhaphies. We hypothesized that the SSS technique would significantly decrease vascular perfusion compared to the 3LP technique. Under general anesthesia, eight pairs of forelimb SDFTs were transected and either SSS or 3LP tenorrhaphy was performed on each forelimb. The horses were heparinized, euthanatized, and forelimbs perfused with barium sulfate solution then fixed with formalin under tension. The tendons were transected every 5mm and microangiographic images were obtained using a Faxitron X-ray cabinet with computed radiography imaging. Microvascular analysis of sections proximal to the tenorrhaphy, throughout the tenorrhaphy and distal to the tenorrhaphy was completed using Image J software and a custom macro. A significant reduction in the number of perfused vessels was seen in the SSS compared to the 3LP at two locations within the tenorrhaphy (p=0.004 and 0.039). The SSS technique took on average 4.7 ± 0.9 times longer to place. The SSS technique causes a reduction in tendon perfusion compared to the 3LP, which may limit its clinical use. Further research is required to elucidate the clinical significance of this difference. / Master of Science

Nearly 50% of the equine population is overweight due to feeding and management practices. Obesity is related to development of diseases that are detrimental to performance and potentially fatal in horses, including insulin resistance, laminitis, and equine metabolic syndrome (EMS). Objectives of this research included first, characterization of nutrition-related management practices of hunter/jumper show industry via a voluntary survey; second, evaluating the Body Condition Index (BCI) in comparison to the Body Condition Scoring system (BCS) in sporthorses; and lastly, determining the effects of a hindgut buffer in overconditioned horses following an abruptly introduced moderate nonstructural carbohydrate (NSC) meal. There were no differences in nutritional management between hunter and jumper disciplines and most representatives (n=89) had no nutritional concerns. Many used trainers (38%) and veterinarians (36%) as sources of nutritional advice rather than professional equine nutritionists (7%). BCI had consistently higher scores than BCS (P<0.01), with the largest differences in horses with BCS < 5. Horses were offered a concentrate meal containing 1.2g NSC/kg BW with and without DigestaWell® Buffer (DB). Horses receiving DB had decreased plasma L-lactate (P=0.05), and a tendency for increased fecal pH (P=0.08) and decreased fecal D-lactate (P=0.07). These studies demonstrate a need to improve horse owner education and the relationship between representatives and trained nutritionists to reduce disease incidence, that different equations may need to be developed for a more consistently accurate BCI across various breed and body types, and that DB may have a positive impact on the equine digestive response to NSC. / Master of Science

Objective: To assess the safety and efficacy of lyophilized milled human amnion as a wound dressing of experimentally created equine distal limb wounds. Animals: Four clinically normal adult horses (3 Thoroughbred and 1 Paint, median age 11 years) obtained via donation. Procedures: One forelimb of each horse was randomly assigned to the treatment group, and the contralateral limb was assigned as the control. Full-thickness skin wounds were created on each metacarpus. Treatment limb wounds were dressed with lyophilized, milled, human-derived amnion material delivered under triple antibiotic ointment. Control wounds were dressed with triple antibiotic ointment. All wounds were covered in non-adherent dressings and distal limb bandages were applied. Digital photographs were taken of the wounds at each bandage change, performed every 2-4 days throughout a 98-day study period. Biopsies were collected at days 7, 21, 35, and 84. Results: One horse developed unilateral cellulitis that resolved with additional treatment. All treatment limbs exhibited an inflammatory response characterized by focal edema and discharge from the wounds. Wounds were completely epithelialized in control limbs sooner than treatment limbs in all horses, although there was no statistical difference between control (mean 46.8 days) and treatment (mean 51.8 days) wounds. Histologic scores were better in control wounds than in amnion-treated wounds at all time points. Conclusions and Clinical Relevance: Because wounds treated with amnion material in this study exhibited an inappropriate inflammatory response that resulted in delayed time to wound closure, human lyophilized milled amnion is not recommended for use in equine wound management. / Master of Science

Equine-assisted psychotherapy is emerging as a new alternative therapy method. As the field is new, there is limited amount of research looking at the current theoretical foundation being utilized in the therapeutic process. This study aims to explore the field of equine-assisted psychotherapy and its current theoretical foundation. The main question guiding this study was: What are the therapeutic theories and themes guiding the current practice of equine-assisted psychotherapy? The study consisted of six in-person qualitative interviews with current practitioners of equine-assisted psychotherapy. A short Likert-type scale was also used to quantitatively gather descriptive statistics about theories currently being used by these practitioners. The results of this study yielded interesting findings about the similarities between equine-assisted psychotherapy and traditional office therapy. The use of horses in therapy creates new dynamics to be addressed in the therapeutic process. The practitioners interviewed in this study agreed on many different aspects about the application of equine-assisted psychotherapy to clients displaying characteristics of trauma, anxiety, depression, and boundary issues, but also had dissenting opinions about other aspects of the practice. The generalist model of social work practice is utilized in the questionnaire. This method of questioning found that the use of the generalist model is applicable to the field of equine-assisted psychotherapy.

Equine Assisted Activities and Therapy (EAA/T) is a non-invasive treatment modality recommended by the medical and educational community for a subset of challenged children and adults. As its popularity increases, so too are the concerns among stakeholders and the medical and educational professions about its legitimacy as a treatment modality. The main concern being that EAA/T practitioners have not acquired the professional skills required and that the EAA/T treatment programmes are not evidence-based. The central question of this research focused on identifying Equine Assisted Activities and or Therapy (EAA/T) and creating an optimal learning curricula and more practical experience for future practitioners. In order to explore these issues an extensive multi-method research study was conducted to identify gaps in EAA/T curricula, which included a review of empirical data and different curriculum models. The Delphi Method (DM), a robust, qualitative, naturalistic, systematic and interactive research method was used to support the research. Part of the DM required an analysis of data, adaptation of issues and amendments to questions culminating in a collective consensus among EAA/T experts. The key research findings suggested that current training programmes use curricula with significant gaps resulting in poor professional knowledge formation, a lack of experiential learning, insufficient knowledge of equestrianism and an inability to use pedagogic paradigms. Other findings showed that curricula being used were not being built as an application of sound theoretical principles but rather, transmitted in a manner that does not motivate active and meaningful learning or promote the best practical experience. As a consequence, national organisations and academies dedicated to EAA/T training sidestep high standards and core values for the sake of membership and financial gain. This rigorous research study has highlighted gaps in current training practices and has made it possible to make recommendations for a future curriculum. Recommendations that suggest the future curriculum is built on sound theoretical principles developing foundation knowledge to operate EAA/T in all fields of practice. This could set new quality and performance benchmarks and provides EAA/T practitioners with adequate tools to connect best practices to people with real-life challenges.

Mental disorders are a prevalent health issue that has an extensive amount of variability in the quantity of disorders, affected populations, and treatment. There are a multitude of approaches or therapeutic methods used by the mental health community. Although each therapy is valuable in unique ways, each therapy may not be suitable to treat every disorder or client. Traditional approaches, such as talk therapy, are effective for certain individuals, whereas some clients may not respond well to any of the traditional talk therapies. When traditional therapies are not working, a referral can be made for a therapy that might suit the client better. Equine-Assisted Psychotherapy (EAP) is an experiential psychotherapy that has done well not only in assisting typical clients, but also with clients that have had trouble in traditional modes of therapy. This is a collaboration of current works and research in EAP, along with the knowledge base of a current licensed practitioner of EAP. The purpose is to lay out the fundamentals of EAP, which offers a different modality than traditional talk therapies. By crafting a better picture of EAP, perhaps it can kindle further research in its efficacy and guide additional mental health professionals towards this type of therapy.

Chronic neuropathic pain, resulting from dysfunction of the nervous system, is a clinical concern in both humans and animal patients. Neuropathic pain is characterised by spontaneous pain, hypersensitivity, manifested as hyperalgesia and allodynia, and refractoriness to conventional analgesics such as non-steroidal anti-inflammatory drugs, thus representing an unmet therapeutic need. Equine laminitis is a disease that involves the disruption of the dermoepidermal junction within the hoof, leading to severe pain and lameness, with poor responsiveness to anti-inflammatory therapy. We developed a Quantitative Sensory Testing method, using a novel hydraulically-powered feedbackcontrolled hoof tester, in order to provide an objective tool for the assessment of mechanical hyperalgesia in laminitic horses. Hoof Compression Thresholds of laminitic horses were significantly lower than those of normal horses and variance component analysis of the data confirmed the reliability of the method. In order to investigate mechanisms underlying laminitis pain, we performed histological studies of peripheral nerves innervating the hoof. Electron micrographic analysis of the digital nerve of laminitic horses revealed a significant reduction in the number of unmyelinated and myelinated fibres together with abnormal morphology. Additionally, cell bodies of sensory neurons innervating the hoof in cervical C8 dorsal root ganglia showed an upregulated expression of the nerve injury marker activating transcription factor-3 (ATF3), neuropeptide Y (NPY), and the TRPM8 channel; each of which has been associated with laboratory models of neuropathic pain. Previous work has shown that, in a rodent model of neuropathic pain, the TRPM8 channel is upregulated in sensory neurons and its activation by cool temperature, menthol or icilin leads to reversal of the hypersensitive pain state. Further investigation of TRPM8-channel mediated analgesia was aimed at uncovering the molecular mechanisms involved in the activation of this system in sensitised states. It was hypothesised that serotonin, released following inflammation and nerve damage, can enhance TRPM8 channel activity through peripheral 5-HT1B receptors. Calcium fluorometry carried out in HEK293 cells transfected with the TRPM8 channel and the 5-HT1B receptor revealed that coadministration of a 5-HT1B receptor agonist facilitated the activation of the TRPM8 channel by icilin. Moreover, it appears that this effect is mediated through phospholipase D1 (PLD1), possibly leading to increased production of phosphatidylinositol (4,5-) bisphosphate (PIP2), a known positive modulator of TRPM8 channel activity. In vitro co-immunoprecipitation studies suggested that the TRPM8 channel, the 5-HT1B receptor and PLD1 physically interact with each other, further providing a molecular basis for their functional co-operation. Calcium imaging carried out in cultured rat DRG cells showed that the 5-HT1B receptor-mediated enhancement of icilin responses at the TRPM8 channel also occurs in sensory cells and is reversed by inhibition of PLD1. Moreover, TRPM8 and the 5-HT1B receptor appear to be physically associated in vivo as shown by their co-immunoprecipitation from spinal cord homogenates. Assessment of nociceptive behavioural reflexes following intrathecal injection of selective pharmacological agents provided further support for the idea of 5-HT1B receptor facilitation of TRPM8 channel responses in vivo. In addition to providing novel evidence of a neuropathic component to equine laminitis and validation of a novel QST method for pain assessment in horses, this study reveals for the first time a physical and functional interaction between the 5-HT1B receptor and the TRPM8 channel.

The examination of 220 normal and 130 diseased equine (extracted) cheek teeth was performed using a variety of traditional and novel imaging techniques primarily to assess the aetiopathogenesis of the important dental disorders of apical infection and "idiopathic" dental fracture. Optimal settings for radiography and computer axial scanning of normal and diseased cheek teeth were determined. It was found that standard radiography of extracted cheek teeth was very poor at identifying intradental anatomical or pathological features, whilst computer axial scanning gave accurate information on both normal and abnormal radiographic features. Newly established histological techniques allowed preparation of undecalcified sections of 4-6 μm thickness, and undecalcified sections of 50-60 μm thickness. The current classification of equine dentine was modified, with primary, regular secondary, irregular secondary and tertiary dentine all being categorised separately. Previously undescribed histological features of normal and diseased equine teeth were identified such as dentinal pearls, interglobular dentine, caries and the presence of pioneer micro-organisms. The normal endodontic anatomy of all 24 cheek teeth was established, with individual pulp horns being identified using a unique numbering system. Anatomical parameters of dentine were established for normal cheek teeth, and these were compared to those of apically infected cheek teeth. A decreased presence of primary and secondary dentine, predentine and intertubular dentine was found in diseased teeth compared with normal cheek teeth, but increased number of resting lines were present in diseased cheek teeth. Analysis of 50 individual apically infected cheek teeth showed anachoretic pulpitis to be the most common aetiology, with occlusal pulp exposure often being a secondary finding. Apical infection caused by periodontal disease or infundibular caries was uncommon finding. Fracture patterns to the clinical crown of equine cheek teeth were grouped, with most fractures involving the buccal pulp horns of both maxillary and mandibular cheek teeth.