The aim of this study was to determine whether three acupuncture treatments affected thoroughbred racehorses in training. Heart rate variability (HRV) at rest and stride parameters (SP) during a 600m gallop were measured. Needles were inserted for 20 minutes into pre-selected acupuncture points in the treatment horses while those in the non-treatment group were haltered. The delta values (post-treatment minus pre-treatment) of the groups were compared. There were no significant changes (p < 0.05) in the HRV indicators. The treatment group showed (delta median of treatment vs. non-treatment group) that the parasympathetic (PNS) indicators shifted towards inhibition of the vagal system (RMSSD = - 2.19 vs. 1.47; HF = - 37.19 vs. 19.42; SD1 = - 1.56 vs. 1.04). The delta medians of indicators associated with the combined effect of the PNS and sympathetic nervous system (SDNN = 4.39 vs. - 4.00; LF = 179.48 vs. - 397.26; SD2 = 8.55 vs. - 7.48); cardiac autonomic balance (LF/HF = 0.26 vs. - 0.32; LF norm = 14.23 vs. - 0.80; HF norm = - 4.78 vs. 3.54) and heart rate measures (Mean HR = 3.96 vs. - 3.00; Mean RR = - 169.72 vs. 107.54) showed a shift in opposite directions. The SP results showed a significant increase in maximum stride count (p = 0.004). The delta medians showed a shift in opposite directions i.e., average stride length (-0.06 vs. 0.05), average stride count (0.31 vs. -0.26), maximum stride count (0.84 vs. -5.70), maximum speed (1.30 vs. -0.80) and stride length at maximum speed (0.13 vs. -0.01). Thus, the non-treatment group seemed to perform better and were calmer, suggesting that a withdrawal period may be appropriate following acupuncture treatments. / Dissertation (MSc (Veterinary Sciences))--University of Pretoria, 2021. / AgriSETA bursary / Companion Animal Clinical Studies / MSc (Veterinary Sciences) / Unrestricted

Traditional methods of blood glucose monitoring involve obtaining samples for measurement via laboratory methodology or point of care devices and require invasive collection techniques such as capillary stick, venipuncture, or the placement of intravenous catheters. Limitations of traditional methods include the limited information provided by intermittent testing and the stress associated with restraint and discomfort experienced by patients. The snapshot nature of the provided information restricts a clinician's ability to truly monitor trends in glucose concentrations over an extended period of time, influencing clinical decision making. The stress of invasive sampling can cause stress hyperglycemia in many veterinary species, complicating interpretation. Continuous interstitial glucose monitoring technology is widely used in the human medical field due to the expansive information provided in a minimally invasive manner. In recent years, the device technology has advanced and cost has improved, prompting application of these devices into the veterinary sector. Studies have shown good agreement between newer glucose monitoring systems and traditional methods in small animal patients with diabetes mellitus, allowing veterinarians to obtain comprehensive glucose data with minimal stress and discomfort to the patient. However, information regarding the use of this new technology in equine medicine is limited. The following study describes the evaluation of two widely available glucose monitoring systems, the Dexcom G6 and the FreeStyle Libre, in healthy adult horses. / Master of Science / Monitoring of glucose concentrations is essential for the diagnosis and monitoring of a variety of disorders within equine medicine. Traditional methods of obtaining samples for testing include capillary stick, venipuncture, or the placement of intravenous catheters, which can cause stress and discomfort to equine patients. The information obtained by this testing methodology only allows for intermittent assessment of glucose concentrations, limiting the amount of information available for clinicians to make clinical decisions. The use of continuous glucose monitoring systems in the human medical field have allowed clinicians to obtain continuous or near-continuous glucose concentrations, improving interpretation. These devices have nearly eliminated the need for blood sampling for glucose concentrations, instead relying on interstitial glucose concentrations which have been shown to compare favorably to blood concentrations. Studies in small animal veterinary species, such as dogs and cats, have shown good agreement between newer glucose monitoring systems and traditional methods in small animal patients with diabetes mellitus, allowing veterinarians to obtain comprehensive glucose data with minimal stress and discomfort to the patient. However, information regarding the use of this new technology in horses is limited. The study described in the manuscript following evaluates the use of two widely available glucose monitoring systems, the Dexcom G6 and the FreeStyle Libre, in healthy adult horse.

Uterine inflammation after breeding is considered necessary for the clearance of excess semen and debris from the uterus. A subpopulation of mares fails to clear the inflammation in a timely fashion, and develops a persistent breeding induced endometritis (PBIE). Experiments were preformed to evaluate correlations of PBIE to endometrial quality and age. Mares of advanced age and poor endometrial quality had a higher incidence of PBIE. In addition, mares fluctuated in susceptibility to PBIE from one season to the next. The uterine inflammatory gene expression in susceptible and resistant mares within the first 24 hours after breeding was investigated. The peak endometrial cytokine gene expression occurred 6 hours after insemination, and susceptible mares were found to have a reduced response of the inflammatory modulating cytokines during this time. Intrauterine accumulation of the inflammatory byproduct nitric oxide (NO) was investigated in resistant and susceptible mares within the first 24 hours after breeding. Susceptible mares had an increase in NO accumulation over time, whereas NO accumulation in resistant mares remained relatively constant. The effects of immunomodulators on uterine inflammatory response and nitric oxide accumulation in susceptible mares was investigated. Immunomodulators decreased expression of the pro-inflammatory cytokine interleukin-1β and nitric oxide accumulation. In conclusion, endometrial quality and age are indicators of susceptibility to PBIE, and susceptibly can change from year to year. Six hours after breeding is a critical time for the development of PBIE, and susceptible and resistant mares have differential endometrial inflammatory gene expression, with susceptible mares appearing to have a defect in the inflammatory modulating immune response. Finally, treatment with immune modulators alters the IL1β gene expression and intrauterine nitric oxide accumulation, which may help to explain how they act to reduce inflammation during PBIE.

Made available in DSpace on 2016-04-28T20:15:27Z (GMT). No. of bitstreams: 1 2007- Melissa Silva Leme Dalarme.pdf: 688269 bytes, checksum: 3f272a90e705a8b058ddf585d70d6cb3 (MD5) Previous issue date: 2007-02-23 / Funda??o Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / A retrospective study was carried out with the objective to identify risk factors and the incidence of training failure among Thoroughbred racehorses. Two hundred fifteen Thoroughbreds had been evaluated, in the period of January 2001 to December 2003, at Rio de Janeiro-RJ. All the horses had been displayed to the same conditions of handling, feeding and athletical training. The veterinary evaluation of the horses was carried through daily and the clinical notations, protocol training beyond the campaign of the horses, had been registered individually being later enclosed in the management veterinarian software. The complementary examinations had been image diagnosis, laboratorial clinical analysis and, when necessary, the microbiological examination. The clinical causes or for veterinary intervention of interruption in the training of the equines had been categorized the relative data to the causes of interruptions of horses training had been submitted initially to the descriptive analysis. The independent variables had been evaluated individually in relation to the association with interruptions of training using contingency tables and Chi-Square test. A total of 351 cases of training failure was recorded, 54,7% due lameness, 11,1% due to respiratory infections, 16,5% due to hemoparasitosis and 17,7% due to other causes. The rate for fillies was always lower than for colts. Incidence of lameness among horses increased to the beginning of more intensive training. The incidence of respiratory infections never exceeded 18% and was higher in the group of 2-years-old. It can be concluded that the lameness was the most important of the causes of training failure among Thoroughbred racehorses and its incidence with age is directly proportional to the increase of the training intensity. / O estudo retrospectivo foi realizado com o objetivo de identificar fatores de risco e a incid?ncia de interrup??o no treinamento de eq?inos de corrida da ra?a Puro Sangue Ingl?s. Foram avaliados 215 eq?inos no per?odo de janeiro de 2001 a dezembro de 2003, no Rio de Janeiro. Todos os eq?inos foram expostos ?s mesmas condi??es de manejo, alimenta??o e treinamento atl?tico. A avalia??o veterin?ria dos eq?inos foi realizada diariamente e as anota??es cl?nicas, monitoramento do treinamento, al?m da campanha dos eq?inos, foram registradas individualmente sendo posteriormente inclu?das no software de gerenciamento veterin?rio. Os exames complementares utilizados foram o diagn?stico por imagem, an?lise cl?nica laboratorial e, quando necess?rio, o exame microbiol?gico. As causas cl?nicas ou por interven??o veterin?ria de interrup??o no treinamento dos eq?inos foram categorizadas Os dados relativos ?s causas das interrup??es no treinamento dos cavalos foram submetidos inicialmente ? an?lise estat?stica descritiva. As vari?veis independentes foram avaliadas individualmente em rela??o ? associa??o com interrup??es no treinamento usando tabelas de conting?ncia e o teste do Qui-Quadrado. Foram observados 351 casos de falhas no treinamento, 54% devido ?s claudica??es, 16,5% devido ?s hemoparasitoses, 11,1% devido ?s altera??es respirat?rias e 17,7% devido a outras causas. A ocorr?ncia nas f?meas foi sempre inferior ? dos machos. A incid?ncia de claudica??es entre os eq?inos aumentou com o in?cio do treinamento mais intenso e, a incid?ncia de altera??es respirat?rias n?o excedeu 18% e foi maior no grupo de dois anos de idade. Pode-se concluir que as claudica??es s?o as mais importantes das causas de interrup??o no treinamento de eq?inos de corrida da ra?a Puro Sangue Ingl?s e sua incid?ncia com idade ? diretamente proporcional ao aumento da intensidade de treinamento.

Studies described in this thesis were performed to investigate associations among season, diet, pituitary pars intermedia dysfunction (PPID) and blood concentrations of adrenocorticotropic hormone (ACTH), insulin, glucose, and leptin in horses. In the first study, higher ACTH concentrations were detected in horses affected with PPID. A seasonal increase in plasma ACTH concentration was detected in the late summer and early fall, but PPID did not affect the timing or duration of this increase. Pasture grazing raised glucose and insulin concentrations with a peak in September, at the same time that horses had higher ACTH concentrations, and this convergence of risk factors may raise the risk of laminitis. All of the horses included in this study were from the same farm. The second study was performed to determine whether horses from different locations within the same region exhibited the same seasonal increase in ACTH concentrations. Results of this study indicate that the seasonal increase in plasma ACTH concentrations occurs in horses from different farms with varying management practices. The third study investigated the effects of season on plasma leptin concentrations in the horses from the first study. We hypothesized that higher leptin concentrations would be detected in advance of the seasonal increase in plasma ACTH concentrations. Results did not support our hypothesis because leptin concentrations increased after ACTH concentrations peaked in September. Our findings suggest that the seasonal increase in ACTH concentrations induced leptin resistance, which might facilitate weight gain in the autumn. Alternatively, leptin concentrations increased as a result of weight gain or change in body fat composition. In summary, season appears to signal upregulation of the hypothalamic-pituitary-adrenal axis in horses, in an effort to prepare for winter. This upregulation is retained in horses with PPID, a disorder associated with loss of dopaminergic inhibition to the pars intermedia of the pituitary. The seasonal rise in plasma ACTH concentrations is followed by an increase in leptin concentrations, which suggests the development of leptin resistance or an increase in adiposity.

Two types of placentitis were studied: ascending and nocardioform placentitis. Although the first diagnosis of nocardioform placentitis was made three decades ago, little is known about the disease, due to the lack of an experimental model. In attempt to develop a research model, Crossiela equi was inoculated through intrauterine, intravenous, intrapharyngeal, and oral routes, but none of the routes resulted in nocardioform placentitis. This may indicate that unidentified factors may play a role in disease pathogenesis and that simple presence of bacteria is not sufficient to induce nocardioform placentitis. The second and major component of this dissertation involved the identification of diagnostic markers for placentitis. Because ascending bacterial placentitis is readily and predictably induced using existing experimental models, this model was used to identify diagnostic markers for placentitis in maternal plasma and fetal fluids. Three potential biomarkers were examined: acute phase inflammatory proteins, steroid hormones produced by the fetoplacental unit, and protein composition of the fetal fluids. Of the three acute phase proteins investigated, serum amyloid A and haptoglobin but not fibrinogen increased in association with experimentally induced ascending placentitis. Androgens and progestins appear to be poor markers for placentitis. Serum estradiol 17β concentrations were reduced in mares with experimentally induced placentitis and appear to be a good marker for placentitis in mares. Different methods were used to study the protein composition of the fetal fluids. Alpha-fetoprotein was characterized as a major protein present in the equine fetal fluids, and this protein was elevated in plasma of mares with placentitis. In another study, using a high-throughput proteomic technique several new proteins were characterized in the amniotic and allantoic fluids of mares carrying normal pregnancies, and several previously uncharacterized proteins were detected in the allantoic fluid of mares with placentitis. Three secreting proteins were elevated in allantoic fluid of mares with experimentally induced ascending placentitis.

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 not induce the condition. This could be related to differences between experimental models and naturally occurring disease. Studies presented in this dissertation address the overall hypothesis that systemic inflammation causes laminitis and new experimental models can be developed to better represent clinical disease. Associations between systemic inflammation and laminitis were first established by measuring blood inflammatory cytokine expression during a laminitis induction model. A clinically relevant endotoxin model that induced laminitis was then sought, but endotoxin administration alone was insufficient to cause laminitis and endotoxin tolerance developed. Endotoxemia was therefore evaluated in conjunction with predisposing factors such as obesity. In horses with EMS, endotoxin infusion caused exaggerated inflammatory responses, and derangements in glucose homeostasis were more pronounced. Laminitis, however, did not develop. Repeated inflammatory events are implicated in the pathogenesis of sepsis-associated organ failure, so a final study was performed to test whether preexisting endotoxemia increased the risk of laminitis during subsequent carbohydrate overload-induced systemic inflammation. This did not occur, however systemic inflammation was more pronounced in horses that developed laminitis compared to non-responders, and tissues rather than circulating leukocytes appeared to be the major source of inflammatory mediators. Our results do not support a role for endotoxin as the causal agent of laminitis, even when combined with predisposing factors. Tissues appear to be an important source of inflammatory mediators, therefore their role in laminitis should be further characterized. Additionally, future investigations should determine whether exaggerated inflammatory responses and loss of glycemic control increase the risk of laminitis in horses with EMS.

Frontal plane slab fractures account for the majority of third carpal bone (C3) fractures in performance horses. Treatment is stabilization with an AO cortical screw. Complications are fragment splitting, fragment spinning, and irritation of dorsal soft tissue structures. A novel, headless, cannulated screw with interlocking threads (the Headless Compression Screw Fastener, HCSF) has been developed to resist multidirectional forces. Simulated C3 slab fractures were created in nine paired equine carpi. HCSF or AO cortical screws were loaded in shear to failure. Stiffness, maximum load to failure, and yield load was assessed in linear mixed models. No significant difference was detected in maximum load to failure, stiffness, or yield load. Mode of failure was screw bending in all specimens. The HCSF successfully repaired simulated third carpal bone fractures. The design eliminates counter sinking. There was no significant difference compared to the cortical screws. These results promote clinical application.

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 in knowledge in this regard is a limited understanding of the specific cellular phenotype of normal, robust articular chondrocytes. This thesis examines the global mRNA transcriptome of equine articular cartilage to test the hypothesis that adult articular chondrocytes have a unique gene expression profile. In the first part of the study, RNA-sequencing was used to compare the mRNA transcriptome of normal adult articular cartilage with five other cartilaginous tissues. From these comparisons, locus level gene expression and alternative splicing patterns have been identified that clearly distinguish articular cartilage. In the second part of the study, fetal (interzone, cartilage anlagen chondrocytes, dermal fibroblasts) and adult (bone marrow derived, adipose derived, articular chondrocytes, dermal fibroblasts) primary cells were grown in culture and stimulated to differentiate into chondrocytes. The chondrogenic differentiation potential as assessed by matrix proteoglycan and the expression of cartilage biomarker genes was highly variable among cell types. Together, these results advance our understanding of the specific phenotype of articular chondrocytes and the potential of prospective therapeutic progenitor cells to differentiate into articular chondrocytes. This new knowledge will improve efforts to optimize cell-based therapies for osteoarthritis and the repair of joint cartilage lesions.

Intra-articular glucocorticoid injections are commonly used to treat synovitis and osteoarthritis in horses. These agents are highly effective at relieving pain, swelling, and other symptoms of joint inflammation. The drugs also have therapeutic benefits by down regulating the expression of cytokines and protease enzymes that participate in the degradation of articular cartilage. However, detrimental effects on chondrocyte function and cell viability that is independent of osteoarthritis pathogenesis have been described and linked to glucocorticoid use. These side effects are both drug- and dose-dependent. This study tested the hypothesis that manufacture recommended dosage levels of methylprednisolone, betamethasone, and triamcinolone that are widely used in equine clinical practice are cytotoxic to articular chondrocytes. Drug-induced chondrocyte cytotoxicity was evaluated in monolayer cultures, cartilage explants, and equine fetlock joints. Total RNA was isolated from control and IL-1β stimulated primary chondrocytes and synoviocytes in culture. Changes in steady state mRNA for targeted gene transcripts related to inflammation and normal cell function were measured using reverse transcription and quantitative PCR. Inducible nitric oxide synthase activity was evaluated using nitrite production. Drug-induced chondrocyte cytotoxicity occurred at drug dosage levels frequently used in equine clinical practice. Both drug- and dose-dependent effects on chondrocyte and synoviocyte gene expression were observed. Maximum anti-inflammatory activities for the glucocorticoids were observed at in vitro concentrations below manufacturer-recommended levels. Results from this study suggest that lower glucocorticoid dose ranges for intra-articular therapy in horses should be validated to maximize the ratio of their therapeutically beneficial anti-inflammatory efficacy against detrimental effects on cell function and viability.