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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.
21

The impact of two dripping systems on endemic stability of bovine babesiosis and anaplasmosis in cattle at four communal grazing areas in Limpopo Province, South Africa

Rikhotso, Boetie Oupa. January 2005 (has links)
Thesis (MSc (Veterinary Science))--University of Pretoria, 2005. / Includes bibliographical references.
22

The comparative assessment of capillary and venous Babesia rossi parasitaemias on thin blood smears and their association with disease manifestation

Böhm, Marlies. January 2006 (has links)
Thesis (MMedVet (Medicine))--University of Pretoria, 2006. / Includes bibliographical references.
23

The pathophysiology of renal and cardiac changes in canine babesiosis

Lobetti, R.G. (Remo Giuseppe) 19 August 2008 (has links)
This thesis showed that dogs with natural infection with B. canis had both renal and cardiac dysfunction, both of which can be classified as complications of babesiosis and would thus necessitate supportive therapy. This thesis demonstrated that RTE celluria, proteinuria, and variable enzymuria and azotaemia occur in dogs with babesiosis. However, these were all minimal changes and all could be consistent with hypoxia, reduced GFR, or reduced cardiac output This thesis showed that dogs with naturally occurring babesiosis had significant urine met-haemoglobin with no evidence of blood met-haemoglobin. The possibility would be that the urinary methaemoglobin was either produced in the kidney or possibly by oxidation of haemoglobin to met-haemoglobin in the bladder. It has been shown experimentally that met-haemoglobin can be toxic. The combination of reduced GFR, anaemic hypoxia, and met-haemoglobin can all act synergistically to cause renal damage. Renal haemodynamics are also much more likely to be abnormal when cardiac dysfunction is present Reduced renal blood flow and glomerular filtration rate are evidence of redistribution of blood flow that commonly occurs in early heart failure. An important finding in this thesis was that dogs with babesiosis had lower serum sodium than control dogs but there was no difference between mild, severe, or complicated cases of babesiosis. In addition, dogs with babesiosis had a lower fractional clearance of sodium than Clinically healthy control dogs, which can be interpreted as sodium retention by the kidneys. This sodium retention would also result in water retention , which will result in an expansion of the plasma volume. In the past heart lesions in canine babesiosis were regarded as rare complications, with the majority of lesions being reported as incidental findings at post-mortem examination of complicated babesiosis cases. This thesis has demonstrated that cardiac lesions to be common in canine babesiosis. This thesis showed that that ECG changes in babesiosis were similar to the pattern described for myocarditis and myocardial ischaemia, and together with the histopathological findings indicated that the heart suffers from the same pathological processes described in other organs in canine babesiosis, namely inflammation and hypoxia. As the clinical application of the ECG changes found in this thesis was limited, cardiovascular assessment should be based on functional monitoring rather than ECG. Using cardiac troponin as a marker of myocardial injury, this thesis showed that myocardial cell injury occurs with canine babesiosis. Cardiac troponins, especially troponin I, are sensitive markers of myocardial injury in canine babesiosis, and the magnitude of elevation of plasma troponin I concentrations appears to be proportional to the severity of the disease. ECG changes and serum cardiac troponin were correlated with histopathology. On cardiac histopathology from dogs that succumbed to babesiosis, haemorrhage, necrosis, inflammation and fibrin microthrombi in the myocardium were documented, all of which would have resulted in ECG changes and elevations in cardiac troponin. Myocardial infarction causes left ventricular failure, which will result in hypotension and an expansion of the plasma volume due to homeostatic mechanisms. This thesis showed that dogs with babesiosis had hypoalbuminaemia, which may be because of intravascular volume dilution due to fluid retention. In disease hypoalbuminaemia can occur as a negative acute-phase protein. In the light of the cardiac changes, hyponatraemia, and hypotension, a probable cause would be fluid retention due to myocardial disease. This thesis showed that dogs with babesiosis had left ventricular lesions, which can result in systolic heart failure. / Thesis (PhD)--University of Pretoria, 2005. / Veterinary Tropical Diseases / unrestricted
24

Modeling human exposure to Babesia spp. utilizing a hunting dog cohort in the United States

Anderson, Bryan 01 August 2017 (has links)
Babesiosis is a disease caused by parasites of Babesia species that is spread through ticks. Babesiosis can affect humans and many other mammals all over the world. In the United States, babesiosis is mainly caused by Babesia microti with additional species of Babesia infecting dogs. Dogs have long been known to be a good indicator species for human tick-borne infection due to the shared spaces they have with humans and their tendency to explore and pick up diseases in the environment. This study used a group of hunting dogs to determine the presence of Babesia infection. The goal was to determine a predictive model for human infection. Infection was defined as having a positive antibody test or molecular test for Babesia species in blood samples. Blood samples were taken at two time points, tested, and compared. Statistical methods were used to analyze the results of the tests and compare them with variables such as region, gender, age, and other diseases the dogs were exposed to. Of 214 dogs, 56 had Babesia infections, with a prevalence rate of 26.2%. At the first time point the model showed age and infection with Anaplasma platys as being significant. At the 2nd time point, 29 dogs were lost to follow up, leaving a total of 185 dogs sampled with 63 testing positive for Babesia spp. The rate for the 2nd time point was 34.1%. No variables were found to be significant in the model for the 2nd time point. Despite differences in Babesia that infect humans and dogs, the hunting dog cohort reflects a model that validates the environmental exposures, coinfections, and demographic variables that affect transmission of the pathogen. Furthermore, findings of this study cast doubt on the ability of Ixodes scapularis to act as capable vector for canine-infecting Babesia species.
25

The occurrence of piroplasms in various South African black rhinoceros (Diceros bicornis) populations

Zimmerman, David Edwin. January 2010 (has links)
Thesis (MSc (Veterinary Tropical Diseases)--University of Pretoria, 2009. / Includes bibliographical references. Also available in print format.
26

The isolation and characterisation of a Babesia bovis stock from outbreaks on a farm in the Swartberg region of KwaZulu-Natal, South Africa

Olds, Cassandra Leah. January 2008 (has links)
Thesis (MSc (Veterinary Tropical Diseases, Veterinary Science))--University of Pretoria, 2008. / Includes bibliographical references. Also available in print format.
27

Prevalence of babesiosis in Sanga cattle in the Ohangwena region of Namibia

Matheus, Emmanuel Kamutyatsha 11 1900 (has links)
Bovine babesiosis is one of the common, economically important tick-borne infectious diseases of cattle. Clinical cases suspected to be babesiosis are frequently observed in the study area. Yet to date, no studies have been done in the farming areas of the north central of Namibia to establish the prevalence of the disease. The objectives of the present study were to determine the sero-prevalence of different Babesia species in Sanga cattle; determine the most prevalent Babesia species and the spatial distribution for two Babesia species in the study area. A total of 392 cattle were randomly sampled and bled to collect blood at various crush pens in all constituencies of the region. This was done during the annual vaccination campaign against lung sickness. The IFA (Indirect Fluorescent Antibody) a method known to have a sensitivity of 95% and specificity of 99%, was used to analyse the samples for Babesia antibodies. The most prevalent species was Babesia bigemina with an estimated prevalence of 36.5%, followed by Babesia bovis at 16.6%. Mixed infections were estimated to be 13.2%. The disease was found to be prevalent throughout the region with no significance association between infection as the dependent variable and independent variables like sex, age and place. The parasite was widely but not uniformly distributed in the study area. There is a need for more farmer education and awareness. The region proved to be endemically unstable for babesiosis, a vaccination protocol to establish good herd immunity is necessary to improve production. Similar studies in different parts of Namibia be performed and that efforts to prepare a local vaccine. Agricultural regulations should also include the removal of old animals to help improve productivity and farmers output. Further research should investigate and map out the prevalence of Babesia parasites and other heamoparasites in each region of Namibia. This information can also contribute towards the development of future interventions and management strategies in animal health / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)
28

Detecção parasitológica, molecular e sorológica de Erlichia canis e babesia canis em cães da região Centro-Oriental da Colômbia

Vargas Hernández, Giovanni [UNESP] 19 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-19Bitstream added on 2014-06-13T19:50:55Z : No. of bitstreams: 1 hernandez_gv_me_jabo.pdf: 1315271 bytes, checksum: 3786d97151b1ddc80c332c8348bf4567 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A babesiose e a erliquiose canina são doenças comuns em cães, transmitidas pelo vetor Rhipicephalus sanguineus. Os sinais e sintomas dessas doenças não são específicos. A detecção dos parasitos em esfregaços sanguíneos nem sempre é possível e a detecção sorológica pode indicar apenas que o animal teve contato com o agente, mas não necessariamente a doença ativa. Na Colômbia existem poucas pesquisas sobre a epidemiologia e diagnóstico de erliquiose e babesiose em cães, as poucas existentes se basearam na detecção dos hemoparasitas em esfregaços sanguíneos, ou de anticorpos específicos. Sendo assim propos-se este estudo com o objetivo de pesquisar a erliquiose e a babesiose em esfregaços sangüíneos associados a provas sorológicas e moleculares em cães da região centro-oriental de Colômbia. Amostras de sangue e soro de 91 cães, provenientes das cidades de Bogotá (n=21), Villavicencio (n=31) e Bucaramanga (n=39) foram submetidas a pesquisa parasitológica, detecção de anticorpos anti-B. canis e anti-E. canis e detecção molecular de Babesia canis e Ehrlichia canis. Os resultados mostraram que dentre as 91 amostras testadas, 4% e 5% delas apresentaram E. canis e B. canis, respectivamente nas pesquisas parasitológicas dos esfregaços sanguíneos. Nas mesmas amostras, 82% e 51% delas apresentaram anticorpos anti-E. canis e anti-B. canis, respectivamente e, em 40% e 5%, foram detectados os DNA de E. canis e de B. canis, respectivamente. Os amplicons foram confirmados por seqüenciamento e o DNA de E. canis e de B. canis obtidos mostraram similaridade genética de 98% a 99% com amostras de E. canis e de B. canis isoladas em outros países, as árvores filogenéticas dos agentes pesquisados foram / Canine babesiosis and ehrlichiosis are common diseases in dogs, and are transmitted by the vector Rhipicephalus sanguineus. The clinical signs of these diseases are not specific. Detection of parasites in blood smears is not always possible and the serological detection could only indicate that the animal has had contact with the agent and not necessarily that the disease is being developed. In Colombia, there are few reports on canine babesiosis and ehrlichiosis´s epidemiology and diagnosis, being them based only on the detection of haemoparasites in blood smears and detection of antibodies. The purpose of the present study was to investigate the presence of Ehrlichia sp. and Babesia sp. in blood smears, associated with serological and molecular detection of these parasites in dog blood samples from the middle east region of Colombia. Blood and sera samples from 91 dogs from Bogotá (n=21), Villavicencio (n=31) and Bucaramanga cities (n=39) were submitted to parasitological, serological and molecular detection of B. canis and E. canis. Among the 91 samples tested, 4% and 5% presented E. canis morulae and B. canis piroplasms in blood smears, respectively. Moreover, 82% and 51% of samples presented antibodies anti-E. canis and anti-B. canis, respectively. E. canis and B. canis DNA were detected in 40% and 5% of samples, respectively. The amplicons were confirmed by sequencing and the found DNA from E. canis and B. canis showed a genetic identity of 98% to 99% among samples from E. canis and B. canis isolated from other countries. Finally, phyllogenetic trees were constructed from both agents
29

The haematological kinetics of canine babesiosis in South Africa

Scheepers, Elrien 16 July 2008 (has links)
The course of the haemopoietic response during canine babesiosis caused by Babesia rossi has not previously been studied. This prospective, descriptive longitudinal study on clinical cases describes the haematological kinetics during the first six days following treatment of natural babesiosis infection. Ninety client-owned dogs diagnosed with B rossi infection, based on examination of a Cam’s Quick-Stain-stained thin capillary blood smear and confirmed by polymerase chain reaction analysis, were included. At first consultation, 24 hours, three days and six days after first consultation, or until death, an EDTA sample was collected from the jugular or cephalic vein and submitted for a full automated blood count, using a CELL-DYN 3700 analyzer. Manual leukocyte differential counts were performed. Based on the treatment protocol, the dogs were divided into a blood transfusion group, and a non blood transfusion group. A slightly to moderately regenerative normocytic normochromic anaemia occurred throughout the study period for both treatment groups. The anaemia was very severe at presentation in dogs that received a blood transfusion and moderate at presentation in dogs that did not receive a blood transfusion. Anaemia was still present by the end of the study period in both treatment groups. The regenerative response was moderate in severely anaemic dogs and mild in moderately anaemic dogs. A mild inflammatory leukocytic response was found in both treatment groups. The median segmented neutrophil count for both treatment groups was within the reference interval throughout the study period. A left shift occurred more commonly in dogs that received a blood transfusion, and was significantly influenced by the degree of anaemia at presentation. In dogs with a left shift, a degenerative left shift, not influenced by the degree of anaemia at presentation, was found more commonly. Severe thrombocytopaenia for both treatment groups, which resolved within a week in both groups, was found. Treatment with a blood transfusion reduced the anaemia, but had no significant effect on white blood cell or platelet responses. Blood cell responses were not significantly influenced by age, previous infection with babesiosis or duration of illness. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2008. / Companion Animal Clinical Studies / unrestricted
30

The role of insulin in blood glucose abnormalities in canine babesiosis

Rees, Philip 04 January 2011 (has links)
Abnormal carbohydrate metabolism is a commonly encountered feature of malaria in people, and similar derangements have been detected in veterinary patients with canine babesiosis. Glucose, the major metabolic fuel source, is a key resource in critically ill patients as they mount an immunological response to infection and inflammation. The ability of the individual to effectively mobilise, distribute and utilise glucose is a major determinant of morbidity and mortality. Hypoglycaemia has been identified as a life threatening metabolic complication in almost 20% of severely ill dogs suffering from babesiosis due to Babesia rossi infection. Insulin and glucagon are the primary hormones involved in glucose homeostasis. Insulin lowers blood glucose concentration by facilitating cellular uptake and utilisation of glucose. Hyperinsulinaemia as a result of inappropriate insulin secretion may precipitate hypoglycaemia, and has been identif ed as a cause of hypoglycaemia in human and murine malaria. A similar phenomenon may exist in canine babesiosis. This prospective, cross-sectional, observational study, including 94 dogs with naturally acquired virulent babesiosis, sought to investigate and characterise the relationship between blood glucose concentrations and insulin concentrations in cases of canine babesiosis. Pre-treatment jugular blood samples were collected for simultaneous determination of plasma glucose and insulin concentrations. Animals were retrospectively divided into three groups: hypoglycaemic (plasma glucose concentration < 3.3 mmol/L; n=16), normoglycaemic (3.3-5.5 mmol/L; n=62), and hyperglycaemic (> 5.5 mmol/L; n=16). The median plasma insulin concentrations (IQR in parentheses) for the hypoglycaemic, normoglycaemic and hyperglycaemic groups were 10.7 pmol/L (10.7-18.8 pmol/L), 10.7 pmol/L (10.7-29.53 pmol/L; i.e below the detection limit of the assay), and 21.7 pmol/L (10.7-45.74 pmol/L), respectively. Statistical analysis revealed no significant difference in insulin concentration between the three groups. These results suggest that insulin secretion was appropriately suppressed in these dogs. Only two dogs had elevated insulin concentrations, one of which was hypoglycaemic. The median time since last meal (available for 87 dogs) was 24 hours (IQR 2-4 days), constituting a significant period of illness-induced starvation. We conclude that hyperinsulinaemia is not a cause of hypoglycaemia in virulent canine babesiosis. It is speculated that prolonged fasting due to disease-induced anorexia, in addition to increased glucose consumption, depletion of hepatic glycogen stores, and hepatic dysfunction with impaired gluconeogenesis, may play important roles in the pathophysiology of hypoglycaemia in canine babesiosis. / Dissertation (MMedVet)--University of Pretoria, 2010. / Companion Animal Clinical Studies / unrestricted

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