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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

The dispersal of African wild dogs (Lycaon Pictus) from protected areas in the Northern KwaZulu‐Natal Province, South Africa.

Whittington‐Jones, Brendan Mark January 2012 (has links)
The number of African wild dogs Lycaon pictus in Northern KwaZulu‐Natal, South Africa has increased substantially over the last six years. This is largely due to a managed metapopulation approach of introductions onto protected areas and private game reserves since 1998. Because of the increasing wild dog population, the likelihood of rural communities surrounding protected areas encountering dispersing wild dogs in northern KwaZulu‐Natal has also increased. Resident wild dog populations currently occur in Hluhluwe‐iMfolozi Park (HiP), Mkhuze Game Reserve (MGR) of Isimangaliso Wetland Park and Thanda Private Game Reserve (TPGR) all of which are bordered by a matrix of natural habitats and human settlements. Thus, land outside these protected areas could be utilized to expand wild dog distribution and provide connectivity between existing resident populations of wild dogs within KwaZulu‐Natal. To investigate the viability of such an approach, Maximum Entropy Modelling (Maxent) was used to characterize habitat niche selection of dispersing wild dogs, and to identify potential dispersal linkages between current wild dog metapopulation reserves. The model was calibrated using 132 location points collected from 2006 until 2009. From 2008 to 2009 I also conducted a survey of 247 community members in tribal authorities bordering HiP and MGR, to understand factors influencing attitudes towards wild dogs. A habitat suitability model with seven predictor variables had an AUC of 0.96 (SD = 0.02) and indicated four variables which best predicted probability of presence for dispersing wild dogs: elevation, road density, land cover and human density. The results suggest that elevation and land cover may be of greater influence for dispersing wild dogs than human density or activity. Elevation was the single most effective variable indicating a higher probability of presence for dispersing wild dogs in lower lying locations; peaking at approximately 200 – 300m a.s.l. Wild dogs also showed a preference for Woodland and Bushland habitats which in KwaZulu‐Natal tend to be found on lower lying topography. A preference for areas of lower human density and a highest probability of presence at road densities of approximately 0.7km/km2 or less would suggest that while wild dogs may show a tendency to avoid areas of high human activity, they can coexist in close proximity to humans. Respondent’s attitudes, knowledge of wild dogs and livestock husbandry were interpreted by the development of a set of indices. Attitudes were positively related to formal education levels and wild dog‐specific education, but were not influenced by demographic factors such as gender, age and employment status. Eighty three percent of respondents believed efforts to protect wild dogs should continue. Respondents with higher numbers of livestock tended to have more positive attitudes towards wild dogs despite generally incurring higher losses to carnivore depredation than those with less livestock. This appears to be because the financial burden of livestock losses to those with fewer livestock is perceived to be a loss of a greater proportion of total financial wealth. The study highlighted the substantial scope for improvement in livestock management. Theft (34 percent), drought (30 percent) and disease (14 percent) were ranked as the greatest problems facing livestock owners while predators were ranked as the greatest problem by only 4 percent of respondents. My findings suggest that wild dogs are generally viewed positively or with ambivalence. Concerns over the potentially increasing threat to livestock, as natural prey numbers outside protected areas decline and wild dogs disperse from natal packs, are likely to be manageable. However, wild dog population expansion within KwaZulu‐Natal will continue to rely on managed core populations on perimeter‐fenced metapopulation reserves with tolerant communities and landowners contributing to the connectivity of isolated reserves. Generation of tolerance can be instilled through continued advocacy and education, supported by conflict mitigation initiatives and rapid response to conflict reports. The implementation of incentive schemes for adjoining private landowners to co‐manage wild dog populations will need to be addressed in conjunction with managed metapopulation practices and law enforcement, to promote range expansion, and reduce potentially lethal edge effects and wild dog‐human conflict.
112

Serial plasma glucose changes in dogs suffering from dog bite wounds.

Du Plessis, Cornelius Johannes 01 November 2007 (has links)
Objective: To describe the changes in plasma glucose concentration in severely injured, canine to canine bite wound cases admitted for veterinary treatment. The changes were measured over a period of 72 hours from the initiation of the trauma. Historical, signalment, clinical and haematological factors were investigated to determine their possible relationship to blood glucose concentration. Hypo- and hyperglycaemia have been associated with death from sepsis and acute injury. Method: Twenty dogs admitted to the Intensive Care Unit at Onderstepoort Veterinary Academic Hospital (OVAH) with severe bite wounds were evaluated. The time of injury was established by questioning the dogs’ owners. Blood was taken on admission for haematology and plasma glucose concentration. Haematology was repeated every 24 hours and glucose every 8 hours, measured from the time the dogs were first bitten. Results: On admission, 5% (1/20) of the dogs were hypoglycaemic, 40% (8/20) were normoglycaemic and 55% (11/20) were hyperglycaemic. No other dogs showed hypoglycaemia during the study period. The median glucose at each of the ten collection points, prior to the 56-hour collection point and at the 72 hour collection point, was in the hyperglycaemic range (5.8mmol/l to 6.2mmol/l). Puppies and thin dogs had considerably higher median plasma glucose concentrations than adult and fat dogs at 0 and 16 hours respectively (P < 0.05 for both). A high incidence of SIRS was encountered (65% to 80%). Fifteen dogs were alive at 72-hours. Thirteen dogs (81.3%) eventually made a full recovery. Three out of four dogs (75%) that were recumbent on admission, died, whereas all dogs (12/12) admitted with either an alert or depressed mental status survived (P = 0. 004). Clinical significance: The high incidence of hyperglycaemia may be explained by the ‘diabetes of injury’ phenomenon. The role of insulin therapy in the treatment of severe injuries should be explored in future studies, as its use in the treatment of human ICU cases, has resulted in a substantial reduction of fatalities resulting from acute injury. The high incidence of death and initial hyperglycemia in the collapsed group and the higher plasma glucose concentrations found in puppies and thin dogs warrants further investigation with a larger group of animals. / Dissertation (MMedVet (Small Animal Surgery))--University of Pretoria, 2007. / Companion Animal Clinical Studies / MMedVet / unrestricted
113

Prairie Dog (Cynomys Ludovicianus) Contributions to Soil Change on Grazed Mixed-Grass Prairie

Barth, Cory John January 2012 (has links)
Vegetation and soils were evaluated on a black-tailed prairie dog (Cynomys ludovicianus) colony and adjacent non-disturbed mixed-grass prairie in central South Dakota. The study’s objectives were 1) determine differences in plant species diversity and richness, and selected soil quality parameters between prairie dog colonies and adjacent non-disturbed sites, and 2) evaluate impacts of prairie dogs on water infiltration rates. Three soil series were evaluated representing three ecological sites (Opal, Cabba, and Wayden). Plant species richness was higher on the Control on Opal soils, while being lower on the Control on Cabba soils. Lower soil pH and higher nitrate concentrations were found on the prairie dog town for Opal and Cabba soils near the soil surface, close to the prairie dog mounds. These findings show prairie dog impacts on soil parameters can vary across different soil types, which can affect the diversity and richness of vegetative communities within prairie dog colonies.
114

Development of a recombinant adenoviral immunocontraceptive vaccine (Ad-GKT) for use in domestic dogs

Arnold, Danielle Patricia January 2021 (has links)
Rabies is a viral disease caused by the rabies lyssavirus (RABV). Despite effective rabies vaccines for humans and animals, this disease continues to pose a major public health challenge, causing an estimated 59 000 human deaths each year, over 99% of which are caused by the domestic dog (Canis familiaris). Current methods of dog population management used in rabies control programs are ineffective. Surgical sterilisation does not reach enough of the dog population to curb population densities and contraceptives need to be administered at a specific phase in the oestrous cycle or cause a range of side effects. Immunocontraception in dogs would allow rabies vaccination coverage to be maintained, in turn reducing the burden of rabies on public health. The aim of this study was to develop an immunocontraceptive vaccine for dogs capable of eliciting a stronger immune response than that of previously constructed vaccines allowing for effective dog population management and allowing rabies vaccination coverage to be maintain, in turn reducing the burden of rabies on public health. By stabilising the dog population size, the 70% vaccination coverage required to interrupt rabies transmission within a population can be maintained. The immunocontraceptive vaccine constructed in this study contained two reproductive hormones, namely GnRH and kisspeptin, in the hope of eliciting a stronger contraceptive effect than either of these could produce alone, as well as the partial tetanus toxoid gene as an immune stimulant. The nucleic acid GnRH, kisspeptin and partial tetanus toxoid gene (GKT) insert fragment was PCR amplified from a DNA construct (pVAC-GKT) and was cloned into the adenoviral vector using In-fusion cloning technology. Transfection of pAdeno-X 293 cells was confirmed using green fluorescent microscopy and expression of the Ad-GKT mRNA in cell culture was confirmed using real-time RT-PCR. The antigenicity of the Ad-GKT construct was evaluated using female Swiss Webster mice. An indirect ELISA was used to detect seroconversion of the GnRH and Kisspeptin insert fragments. The Ad-GKT construct was successful in eliciting an immune response against GnRH and kisspeptin. Future research should include a comparative study to determine the antigenicity of the Ad-GnRH1 and Ad-GKT constructs in a canine trial for potential use in rabies control programs. / Dissertation (MSc (Microbiology))--University of Pretoria, 2021. / The Poliomyelitis Research Foundation grant (19/89). University of Pretoria postgraduate masters research bursary. Technology Innovation Agency Seed Fund. National Research Foundation grant (122016). / Microbiology and Plant Pathology / MSc (Microbiology) / Restricted
115

A New Device for Stereotactic ct-Guided Biopsy of the Canine Brain: Design, Construction, and Needle Placement Accuracy

Giroux, Alain G. 19 June 2000 (has links)
Computed tomography (CT) is an imaging technique that uses x-ray and computers to create cross-sectional images of structures. Stereotactic CT-guided biopsy is defined as the use of a stable apparatus to direct and perform tissue biopsies under CT guidance. For the brain, the principal advantage of stereotactic CT guidance over other biopsy techniques is its high accuracy in getting a sample from deep-seated lesions. The objectives of this study were to create an inexpensive CT-guided stereotactic device adaptable to different canine head sizes and to test the accuracy of the device for needle placement in deep-seated brain targets. A biopsy device was created that consists of four main components: a CT table fixation device, a head fixture, a needle fixture , and motion control system. Accuracy was tested using 16 head and neck specimens obtained from dogs euthanitized for reasons unrelated to the brain. Deep-seated (caudate nucleus and pituitary gland) targets were identified on CT. After a 5 mm craniotomy, the biopsy needle, with CT monitoring, was progressively introduced into the target. The final needle track distance was measured on CT. The brain was removed and sliced to verify placement of the needle tip within the target and to measure the actual needle track distance. The total cost of materials and construction for the stereotactic CT-guided biopsy device was $785.00. No difference in needle placement accuracy was identified for caudate and pituitary targets. Based on assessments by 2 independent observers, the caudate target was successfully hit 75% of the time. Pituitary targets were successfully hit 96.8 % of the time. Actual needle track lengths were an average of 3.2 mm less that the track length measured on CT. This difference was most likely due to incomplete staining of the bevel part of the needle track on gross specimens. / Master of Science
116

Development of a Pharmacodynamic Assay to Assess the Effect of Cyclosporine in the Canine Patient

Riggs, Caitlin Nicole 11 August 2017 (has links)
Cyclosporine is used in veterinary medicine to treat a number of inflammatory and immune-mediated conditions, however firm oral dosing protocols have yet to be established in the dog. Traditionally a pharmacokinetic approach, through measurement of blood drug concentrations, has been the primary method of establishing if the given dose is effectively suppressing the immune system. However, there is some debate over how well blood drug concentrations correspond to immunosuppression, since individuals can vary in response to the same drug concentration. Our research group believes that a pharmacodynamic approach could alternatively be used to accurately determine cyclosporine dosages in individual patients since this will give a measurement of the immune system’s response to the drug, rather than simply how the body is processing it. This method will give a more accurate assessment of the patient’s immune system, and allow for better immunosuppressant therapy. The objective of this thesis was to develop a quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay that could reliably predict patient outcome during cyclosporine treatment. This assay would essentially work as a diagnostic tool that clinicians can use to help determine if they were using an appropriate cyclosporine dose for their patients. The assay measures cytokine expression of activated T cells, which are the target cell for the active metabolite of cyclosporine. Our objectives were achieved, firstly, through validation of the assay. Since this assay will be used by clinicians throughout the nation, we first established if shipping conditions affected the sample, and therefore assay results. Once the effect of sample storage time and temperature were determined, optimal sample collection timing was established. Finally, cytokine levels were measured in samples from clinical cases and healthy control dogs to examine the difference in cytokine expression between these two groups. An effective and reliable treatment method for cyclosporine has yet to be established in the dog; therefore the results of this thesis will lead to better therapeutic monitoring and more efficient use of cyclosporine therapy in canine patients.
117

The Effects of Prostaglandin F2a, Oxytocin and Gonadotropin Releasing Hormone on Ejaculate Characteristics in the Dog

Hess, Milan B. 07 February 2002 (has links)
Prostaglandin F2a (PGF2a), oxytocin and gonadotropin releasing hormone (GnRH) have been used in bulls, rams, boars, stallions or rodents to increase sperm numbers in the ejaculate. Improving sperm quantity in the canine ejaculate would benefit all assisted reproductive techniques used in this species. The purpose of the present study was to evaluate the effects of PGF2a, oxytocin and GnRH on canine ejaculate characteristics. Eight, mature, medium size (25-30 kg), mixed breed dogs were randomly assigned to one of four treatment groups (N=2 dogs each); each group received one treatment per week for four weeks. Treatments were assigned based on a Latin Square design. A two-week training period was used to acclimate the dogs to manual semen collection. Treatments were 0.1 mg/kg PGF2a 15 minutes prior to collection, 2.5 units/dog oxytocin 10 minutes prior to collection, 50 mg/dog GnRH 60 minutes prior to collection, or 1.0 ml of saline 30 minutes prior to collection. An evaluator that was blinded to treatment analyzed ejaculate characteristics. Samples were evaluated for semen volume, concentration of spermatozoa per milliliter, motility, morphology, total sperm number and total morphologically normal motile sperm number (TNMS). In addition, a subjective ease of collection score was assigned following each collection (Scale 1-9, 1 being easiest to manually ejaculate). Semen concentration, motility and morphology were not different between treatments. Semen volume was greater for dogs treated with PGF2a or oxytocin compared to saline. Total sperm number and TNMS were greater when dogs were treated with PGF2a compared to oxytocin, GnRH and saline (p<0.05). The subjective ease of collection score was lower for dogs receiving PGF2a compared to GnRH or saline (p<0.05). In summary, administration of PGF2a or oxytocin prior to semen collection increased semen volume and PGF2a increased total sperm number in the ejaculate of the dog. It did not appear that treatment with GnRH had an effect on semen parameters evaluated in this study. / Master of Science
118

Correlation of Meniscal Injury to Joint Space Width on Standing Lateral and Standard Tibial Plateau Leveling Osteotomy Radiographic Projections of the Canine Stifle

Won, Wylen Wade 03 May 2019 (has links)
Concurrent meniscal injury in dogs with cranial cruciate ligament tears ranges from 10-70%, and these injuries can increase the risk of developing osteoarthritis. Studies regarding joint space width on knee radiographs in people have indicated correlations between joint space width and meniscal injuries. The aim of this study was to determine if there was correlation between stifle joint space width on three different radiographic projections and meniscal injuries identified at surgery in dogs. Four blinded observers measured the radiographic joint space width three times, and the measurements were compared to surgical findings. Intraclass correlation coefficients for inter- and intraobserver variability ranged from moderate to excellent. There was significance between dogs with a meniscal tear and the corresponding joint space width on standard TPLO lateral radiographic projections. Joint space narrowing is seen with meniscal tears in dogs, and radiography may be a noninvasive way to identify meniscal tears prior to surgery.
119

The effects of pre-emptive analgesia with NSAIDs or tramadol in dogs undergoing tumor removal

Karrasch, Nicole M. 19 November 2014 (has links)
No description available.
120

Bone Damage Associated with Orthodontic Miniscrew Implants

Shank, Stephanie Brooke 20 July 2011 (has links)
No description available.

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