Reasons for performing this study: Metacarpal/metatarsal III condylar fractures are the most common type of fracture associated with Thoroughbred horseracing in the UK, and the most common reason for euthanasia on the racecourse. Prediction of fracture through quantification of exercise-related radiographic changes could enable modification of horse management to prevent this injury, improving animal welfare and reducing wastage. Objectives: The general aims were to validate objective radiographic measurement of exercise-related modelling in distal metacarpal III of Thoroughbred racehorses and to explore their utility for fracture prediction by comparing measurements from horses that sustained a fracture of the lateral condyle of distal metacarpal III with those from controls. The initial objective was to establish methods to measure objectively the following variables in distal metacarpal III: condyle opacity, cortical thickness and metaphyseal angle. Radiographic measurements were correlated with equivalent measurements derived from computed tomography (CT) to determine their accuracy. The second objective was to explore the ability of the radiographic measurements to identify horses at risk of fracture. This was done initially by comparing measurements made from radiographs taken at a single time point between Thoroughbred racehorses with and without a lateral condylar fracture, and subsequently by analysis of measurements from series of radiographs obtained prior to and at diagnosis of lateral condylar fracture as part of routine clinical practice. For the final objective, the maximum density of the palmar condyles of distal metacarpal III was determined using a quantitative CT-based technique. Maximum density was compared between horses with fractures and those without, and comparison made with the maximum opacity measured from radiographs, to investigate whether these measurements could be used to identify horses at risk of fracture. Materials and Methods: Fifty-five metacarpal III bones obtained from Thoroughbred racehorses euthanized on UK racecourses (age range 3-11 years) were divided in to three groups: control (no distal limb fracture, n=30), non-fractured (contralateral limb lateral condylar fracture, n=11) and fractured (lateral condylar fracture, n=14). All limbs were subjected to radiography and computed tomography for measurement of diaphyseal cortical thickness 2.5cm distal to the nutrient foramen (expressed as dorsal cortex:medulla width) and metaphyseal angle (deviation of the metaphysis relative to the diaphysis). Measurement of radiopacity of the medial and lateral condyles was calibrated using an aluminium phantom i (condyle:phantom ratio). Correlation between radiography and CT measurements and comparison of radiography measurements between groups was performed. For the longitudinal study, medical records of the Singapore Turf Club were reviewed. Thoroughbred racehorses diagnosed with a lateral condylar fracture that had also been radiographed in the previous 24 months were identified and placed in the ‘high risk’ group (n=16). Horses radiographed and then raced for a minimum of 2 years without suffering a fracture were placed in the ‘low risk’ group (n=15). Twenty-seven metacarpal III bones obtained from Thoroughbred racehorses euthanized on UK racecourses (age range 3-10 years) were used in the investigation of maximum density of the palmar condyles. They were divided in to three groups: control (no distal limb fracture, n=10), non-fractured (contralateral limb lateral condylar fracture, n=8), and fracture (lateral condylar fracture, n=9). Computed tomography measurement of condyle density was calibrated using a potassium phosphate phantom to enable comparison between age-matched bones. Results: Diaphyseal cortical thickness and metaphyseal angle measurements made by radiography and CT were significantly correlated (r=0.74, 0.73; p=0.007, 0.004) but there was no significant difference in measurements between groups. Radiopacity of medial and lateral condyles was significantly greater in non-fracture (0.67±0.04, 0.68±0.04) and fracture (0.82±0.07, 0.68±0.09) groups than the control (0.59±0.08, 0.57±0.09) group (p=0.003). The medial condyle (0.82±0.07) was significantly more radiopaque than the lateral condyle (0.68±0.09) in the fracture group only (p=0.001). In the longitudinal study, the dorsal cortex was thicker in high risk than low risk horses, the mean ± SD cortical thickness ratio of the high and low risk groups was 1.36 ± 0.26 and 1.08 ± 0.19 respectively (p=0.008). Metaphyseal angle measurement displayed a similar pattern and the difference was statistically significant, the mean ± SD metaphyseal angle of the high and low risk groups was 9.65° ± 2.21 and 6.95° ± 1.65 respectively (p=0.000). Computed tomography measurement of maximum density of distal metacarpal III, found no significant difference in maximum density of the lateral and medial palmar condyle between groups. There was a significant correlation between age and maximum density of the lateral condyle (r=0.44, p=0.019) and medial condyle (r=0.54, p=0.003). ii Conclusions: Objective measurement of dorsal cortical thickness and metaphyseal angle of distal metacarpal III can be performed accurately and precisely using radiography in Thoroughbred horses. Radiographic measurement of condyle opacity was precise but conclusions about the accuracy of this measurement await comparison with an appropriate reference standard. Increased radiopacity of the distal condyles was identified in horses that sustained lateral condylar fracture. However, this finding was not reflected by data from the horses represented by the clinical radiographs, suggesting that this measurement may not be useful in identifying horses at risk of fracture. Evidence supportive of this conclusion was provided by maximum density measurements made by CT. Significant differences in dorsal cortical thickness and metaphyseal angle were found between horses that sustained a lateral condylar fracture and horses that underwent radiography for clinical reasons but subsequently raced without fracture, suggesting that these variables could be of value in determining the risk of fracture and merit further investigation.

No description available.

Two methods were used in this research. The pedobarograph is a relatively novel method of gait analysis for animals which enables footfall patterns to be recorded, enabling spatial parameters (step length, width and angle) and plantar pressure patterns to be described and measured. A Kistler force plate was then used to measure the three-dimensional ground reaction forces (GRF's) produced during walking. Speed and cadence can be calculated using either system. Gait patterns are described for normal birds, and for different strains of broilers, raised on different feeding regimes. All the gait parameters were very variable, both between birds, and within the same bird, even when bodyweight and speed were controlled for. Despite the high variability, however, significant differences were identified in many of the gait parameters between the different groups. The vertical and craniocaudal GRF's of Brown Leghorns showed similar characteristics to those produced in human walking. The peak vertical forces were of a similar order of magnitude in the birds as in humans (125-150 % bodyweight), and the peak craniocaudal forces, and the rate of change of force, were closely tied to speed. All the GRF's in the birds increased significantly with increasing speed, except for braking rate (which was more variable) and stance time (which decreased significantly). The mediolateral forces were much greater in the birds than have been reported for other species, however, with peaks of 10-22% bodyweight. Analysis of plantar pressures showed that the pressure were concentrated on the digital pads, with the lowest pressure on the metatarsal pad (131 kNm-2), and highest pressure on the medial toe (up to 218 kNm-2).Combined gait analysis and morphometric studies of ad libitum-fed selected broilers identified many ways in which their gait deviated from that of relaxed broilers and Brown Leghorns, in ways which would serve to increase stability and decrease stresses on the skeleton.

Canine degenerative myelopathy(DM) is a late onset neurodegenerative disease that primarily affects German Shepherd dog (GSD), though a number of other specific breeds are also affected. The underlying cause of the disorder remains elusive, though recent advances have implicated a mutation of superoxide dismutase 1(Sod1) in the aetiology, also implying DM is a potential orthologue of human amyotrophic lateral sclerosis. The identification of the Sod1 mutation raises the index of suspicion for an individual animal, however it is not specifically diagnostic as a proportion of dogs homozygous for the Sod1 mutation do not develop DM. Therefore, there is a clinical need for the development of specific biomarker(s) for DM to support genetic test. The aim of this study was to establish potential biomarkers for DM by exploring canine cerebrospinal fluid (CSF). A dual strategy was adopted;1) Evaluation of potential ALS biomarkers in DM CSF, 2) Identification of novel biomarker(s) in DM CSF. The cases selected in this project had a presumptive diagnosis of DM and were homozygous for Sod1 mutation. Preliminary characterisation by Western blot and mass spectrometry identified four protein candidates in DM CSF, comprised of cystatin C, transthyretin (dimeric and monomeric TTR), haptoglobin and clusterin. Since the validity of these putative biomarkers may be influenced by pre-analytical variables that may arise from the clinical environment, we therefore assessed the impact of three potential sample handling practices on these four proteins. The results from these experiments demonstrate that dimeric TTR and clusterin were affected by sample handling conditions. Therefore, an appropriate protocol for CSF sample handling was established. Western blot analyses indicated that clusterin is the most viable biomarker candidate for DM. Clusterin was significantly elevated in DM CSF when compared to a range of neurological conditions. The second potential candidate for DM biomarker is TTR, which is potentially reduced, an observation similar to those found in ALS CSF. The relationship of these proteins in the pathogenic mechanisms that underpin DM is unclear. However, based on observations on ALS, it is reasonable to speculate that their alterations are associated with a toxic gain of function of the mutant SOD1 protein. The successful characterisation of clusterin and TTR in DM CSF may therefore represent components of a panel of emerging biomarkers that may combine to distinguish DM in the clinic and provide further insights into the disease mechanisms.

Abstract: Tick-borne diseases are a constraint to livestock production in many developing countries. They are responsible for high morbidity and mortality resulting in decreased production of meat, milk and other livestock by-products. The most important tick-borne diseases of livestock in sub-Saharan Africa are East coast fever (caused by Theileria parva), babesiosis (caused by Babesia bigemina and Ba. bovis), anaplasmosis (caused by Anaplasma marginale) and heartwater (caused by Ehrlichia ruminantium). Despite their economic importance, information on the epidemiology of these diseases in many countries is often lacking or inadequate, resulting in inappropriate disease control strategies being implemented. The availability of specific, sensitive and cost-effective diagnostic methods is important in the design and implementation of effective disease control strategies. In this study PCR assays based on the 18S and 16S rRNA gene sequences, that could identify Theileria / Babesia and Anaplasma / Ehrlichia pathogens of cattle respectively, were developed. In addition, PCR assays based on the β-tubulin gene that could detect T. parva, Ba. bigemina, Ba. bovis and T. taurotragi, and PCR assays based on the cytochrome b gene that could diagnose infection by Ba. bigemina and Ba. bovis were also developed. When the 18S and 16S rRNA gene PCR assays were combined into a multiplex PCR assay, Ba. bigemina and E. ruminantium DNA did not amplify and some non-specific bands were observed following agarose gel electrophoresis. The β-tubulin gene multiplex PCR assay for the diagnosis of T. parva, Ba. bovis and Ba. bigemina worked relatively well when used on laboratory-derived parasite DNA preparations. However, when it was used on field samples collected on FTA cards, multiple non-specific bands were observed after agarose gel electrophoresis of the PCR products. The 18S and 16S rRNA gene PCR assays were used for an epidemiological study of tick-borne diseases of cattle in Central and Eastern Zambia in the wet and dry seasons. All the disease pathogens under study (T. parva, T. mutans, T. taurotragi, Ba. bovis, Ba. bigemina, Anaplasma spp and E. ruminantium) were prevalent in all the regions of the country in both seasons. However, variation was observed in the prevalence of these pathogens between the regions and the seasons. A number of risk factors, associated with the occurrence of tick-borne pathogens in cattle and the tick burdens observed on cattle in the wet season were determined. A negative association was observed between the number of co-infecting pathogens and the erythrocyte packed cell volume (PCV) of carrier cattle. Using recently available genome sequences, mini- and microsatellite markers were developed for population genetic analysis of Ba. bovis and Ba. bigemina parasite populations. Ba. bovis isolates from Zambia and Turkey and Ba. bigemina isolates from Zambia were used in the population genetic analysis. High levels of genetic diversity were observed for both parasites. Population genetic analysis of the Zambian and Turkish Ba. bovis populations, using eight genetic markers showed that the two populations were sub-structured. The Zambian population comprised a single randomly mating population, while the Turkish population comprised two genetically distinct subpopulations. Population genetic analysis of the Ba. bigemina parasites from Zambia showed that this parasite population was in linkage disequilibrium. Further, analysis of the Ba. bigemina population using STRUCTURE showed that it was genetically sub-structured into five distinct subgroups. However, the resulting sample size of each subgroup was too small to definitely determine whether they were panmictic. These results provide an improved understanding of the epidemiology of bovine Babesia parasites in Turkey and Zambia.

The present study was conducted to investigate the phannacokinetics (PK) and phannacodynamics (PD) of some nonsteroidal antiinflammatory drugs (NSAIDs), including phenylbutazone (PBZ, in sheep, goats and donkeys), flunixin meglumine (FM, in sheep and donkeys), carprofen and its enantiomers (CPF, in sheep), paracetamol (PRT, in goats and camels) and NG-nitro-L-arginine methyl ester (L-NAME, in sheep).

Acquired urinary incontinence in the canine is a distressing and debilitating condition affecting up to 20% of neutered bitches, whilst less than 1% of entire bitches and males suffer from this condition. Although a number of medical and surgical therapies exist for treatment of acquired urinary incontinence, none are able to cure the condition and many animals become refractory to treatment over time. It has long been thought that a decrease in resting tone within the urethra of a bitch following neutering is responsible for the development of acquired urinary incontinence; however, recent studies show that low urethral tone does not always lead to urinary incontinence, suggesting further factors must be involved. Although the exact aetiology and pathophysiology of the condition in the neutered bitch is unknown, it is thought to have many similarities to that of post menopausal urinary incontinence in women. In this condition, urinary incontinence is known to be mediated primarily by changes in the structure and function of the urinary bladder post menopause. The present study looks at the structure and function of the canine urinary bladder in vitro to determine if changes occur post neutering that could lead a bitch to develop acquired urinary incontinence and which may provide novel therapeutic targets for treatment of this disease. Contractility in response to carbachol (muscarinic) and electrical field stimulation was assessed in isolated strips of detrusor muscle from male and female, intact and gonadectomised canines. The potential role of non-adrenergic, non-cholinergic mediated contraction of the detrusor muscle was also examined and this system does not appear to be significantly altered by gonadectomy. Maximal contractile responses were, however, decreased in detrusor strips from neutered compared to entire canines regardless of gender, with detrusor strips from incontinent bitches having some of the weakest responses. Sensitivity to carbachol was also decreased in detrusor strips from neutered compared to entire canines. This suggests a decrease in contractile function of the urinary bladder in neutered canines and is similar to that seen in the bladders of women suffering from urinary incontinence post-menopause due to impaired contractility of the bladder and idiopathic detrusor instability. This suggests that changes in the function of the bladder post neutering may be partly responsible for the development of acquired urinary incontinence in the bitch. Post-menopausal urinary incontinence in women is hypothesised to be a linked to an increase in the collagen to smooth muscle ratio within the wall of the urinary bladder which is thought to impair bladder contractility and lead to the development of detrusor instability. Morphometric analysis of the urinary bladder wall of canines showed that the percentage of collagen within this organ was significantly increased in neutered compared to entire bitches, with incontinent bitches having some of the highest percentage collagen. The percentage of collagen was unchanged in neutered compared to entire males which were similar to entire bitches. These results support the long postulated theory that a decrease in oestrogen following gonadectomy / menopause is involved in the increase of collagen within the bladder. Results describing the pharmacological characterisation of muscarinic receptors (Schild analysis of pKB values) in strips of canine detrusor muscle suggest that the M3 receptor is the primary receptor responsible for bladder contraction in entire canines in vitro but that the M2 receptor predominates in neutered canines. This previously unreported finding could be significant in providing a novel therapeutic target to treat this debilitating disease. Studies that looked at mRNA expression for the muscarinic as well as the LH and GnRH receptors in canine bladder wall showed that there was an increase in expression of all receptors in tissue from neutered compared to entire canines and that tissue from females had higher expression levels than that from their male counterparts. It is known that gonadotrophin levels in the blood increase post neutering, and that decreasing these levels can provide continence in a number of animals. It is therefore possible, that an up-regulation of mRNA expression for these receptors is involved in the changes at the level of the detrusor that could lead to development of acquired urinary incontinence. It is also acknowledged that the muscarinic pathway is the primary pathway responsible for bladder contraction and emptying, therefore, a change in the expression of muscarinic receptors has the potential to alter bladder contractility as demonstrated previously. In conclusion these studies have shown that the structure and function of the urinary bladder of a neutered canine is altered compared to that of an entire canine, and that these changes have the potential to be involved in the development of acquired urinary incontinence in the bitch. Many of these changes mimic those seen in the bladders of post menopausal women suffering from urinary incontinence, thus suggesting that there may be commonality of disease process between the two species which may allow the use of the canine as a model of human urinary incontinence. This data, the first to include male animals in the study of bladder function and structure, suggest that the loss of oestrogen in the female and the concurrent increase in percentage collagen within the urinary bladder are not significant factors in the development of decreased detrusor contractility per se. On the contrary these results suggest that the muscarinic receptor effector pathway may play a crucial role in the development of altered bladder contractility and acquired urinary incontinence, and may provide a therapeutic target for effective treatment of this disease.

Research was undertaken to investigate whether data maintained within a veterinary hospital database could be exploited such that important medical information could be realised. At the University of Glasgow Veterinary School (GUVS), a computerised hospital database system, which had maintained biochemistry and pathology data for a number of years, was upgraded and expanded to enable recording of signalment, historical and clinical data for referral cases. Following familiarisation with the computerised database, clinical diagnosis and biochemistry data pertaining to 740 equine cases were extracted. Graphical presentation of the results obtained for each of 18 biochemistry parameters investigated indicated that the distributions of the data were variable. This had important implications with respect to the statistical techniques which were subsequently applied, and also to the appropriateness of the reference range method currently used for interpretation of clinical biochemistry data. A percentile analysis was performed for each of the biochemistry parameters; data were grouped into ten appropriate percentile band intervals; and the corresponding diagnoses tabulated and ranked according to frequency. Adoption of a Bayesian method enabled determination of how many times more likely a diagnosis was than before the biochemistry parameter concentration had been ascertained. The likelihood ratio was termed the "Biochemical Factor". Consequently, a measurement on a parameter, such as urea, could be classified on the percentile scale, and a diagnosis, such as hepatopathy, judged to be less or many times more likely, based on the numerical evaluation of the Biochemical Factor. One issue associated with the interrogation of the equine cases was that the diagnoses were clinical in origin, and, because they may have been made with the assistance of biochemistry data, this may have yielded biased results. Although this was considered unlikely to have affected the findings to a large extent, a database containing biochemistry and post mortem diagnosis data for cattle was also assessed.

The work contained in this thesis explores the development of the tibiotarsus shaft and the quality of cortical bone in the modern broiler, in relation to genetic background, growth rate and dietary mineral content. This was achieved through a series of experiments predominantly using a modern selected strain of broiler and an older, unselected control strain, and occasionally utilising current commercial stock. Birds were exposed to a variety of dietary mineral contents, and feeding regimes, and assessments were made of a number of aspects of bone quality, bone turnover, and mineral homeostasis at selected ages .A number of phases in tibiotarsus development were identified from the embryo through to slaughter age at approximately six weeks; these were seen in all strains of broiler chicken investigated. Resorption and replacement of the embryonic cartilage model of the tibiotarsus was found to begin before day 16 of incubation, and a reduction in cortical thickness was observed between this age and hatch as the marrow cavity was enlarged. During this period, the cortex was observed to develop from a maze like scaffold, to display recognisable Haversian canals with the new bone being rapidly mineralised; by day 6, the cortex displayed a distinctive pattern of Haversian canals which remained consistent throughout much of the bird's life-span. From hatch, cortical width began a rapid increase in thickness, which was seen to halt at approximately 18 days of age, cortical thickness remaining approximately constant from this age. The rapid increase in cortical mineral content was also seen to plateau at approximately 11 days.

Haemonchus contortus, a parasitic nematode of sheep, is unsurpassed in its ability to develop resistance to the anthelmintic drugs used as the mainstay of its control. A reduction in drug efficacy leads to prophylactic and therapeutic failure, resulting in loss of productivity and poor animal welfare. This situation has reached crisis point in the sheep industry, with farms forced to close their sheep enterprises due to an inability to control resistant nematodes. The mechanisms of anthelmintic resistance are poorly understood for many commonly used drugs. Altered or increased drug metabolism is a possible mechanism, yet has received little attention despite the clear role of xenobiotic metabolism in pesticide resistance in insects. The cytochrome P450s (CYPs) are a large family of drug-metabolising enzymes present in all species. Their expression is induced on exposure to their substrate and over-expression of a single CYP has been shown to confer multi-drug resistance in insects. The H. contortus genome is currently being sequenced and assembled at the Wellcome Trust Sanger Institute, Cambridge. Despite the lack of a completed genome, the public provision of read, contig and supercontig databases has facilitated the identification of 73 partial gene sequences representing a large family of H. contortus CYPs. Their constitutive expression is highest in larval stages although adult expression was also detected. The majority of CYPs are most highly expressed in the worm intestine, which is thought to be the main organ of detoxification in nematodes and is consistent with a role in xenobiotic metabolism. A small number of CYPs were more highly expressed in anthelmintic resistant isolates than in an anthelmintic-susceptible isolate and may represent candidate genes for further research. The identification of putative H. contortus orthologues of the Caenorhabditis elegans nuclear hormone receptors controlling CYP transcription and the cytochrome P450 reductase gene catalysing electron transfer to CYPs suggests that regulatory and functional pathways may be conserved between the species. Transcriptome analysis using next generation sequencing was undertaken to guide a pilot annotation of 590 Kb genomic sequence. A high degree of conservation was observed between the conceptual translations of H. contortus and C. elegans genes, although at a genomic level, H. contortus consistently had a larger number and size of introns, which may reflect a larger genome than previously predicted. Gene order was not conserved, although regions of microsynteny were present and a bias for intra-chromosomal rearrangements resulted in putative orthologues frequently residing on the corresponding chromosome in both species. Partial conservation of a number of C. elegans operons in H. contortus was identified. These findings have important implications for the H. contortus genome project and the transcriptome databases provide a valuable resource for future global comparisons of gene expression.