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Tumour development is dependent upon the formation of an adequate blood supply through angiogenesis. Vascular endothelial growth factor (VEGF) is one of the most potent and specific pro-angiogenic factors associated with tumour development. Vascular endothelial growth factor is elevated in dogs with a variety of neoplastic tumours and has been linked to an increased risk for metastasis and a poorer prognosis in several tumours. Spirocerca lupi (S. lupi) is a nematode of canids which infests the oesophagus where it forms a nodule. The oesophageal nodule can develop into a neoplastic tumour namely osteosarcoma, fibrosarcoma or anaplastic sarcoma. The pathogenesis of the neoplastic transformation is poorly understood. Diagnosis of neoplastic transformation can be challenging and is based on endoscopy-guided biopsies which are invasive, expensive and may yield non diagnostic samples. The aim of this prospective study was to determine if serum and plasma VEGF levels could be used to distinguish between neoplastic and non-neoplastic spirocercosis. Twenty four dogs were enrolled in the study, 9 with non-neoplastic, 9 with neoplastic spirocercosis, and 6 control dogs. Plasma and serum samples for VEGF analysis were collected at diagnosis. Measurement of VEGF was done using a canine VEGF Quantikine ELISA kit. Statistical analysis to compare the means of the VEGF concentrations between the groups was performed using the Kruskal-Wallis followed by the Dunn’s test. Significance was set at p<0.05 The median plasma VEGF concentration of the dogs with neoplastic spirocercosis 629pg/ml (range 282 – 2366) was higher than the median plasma VEGF concentrations of both the non-neoplastic 0pg/ml (range 0 – 716) and controls 0pg/ml (range 0 – 0) (p<0.001). The median serum VEGF concentration of the neoplastic dogs 69pg/ml (range 0 – 212) was higher than the serum VEGF concentrations in the non-neoplastic 0pg/ml (range 0 – 44.13) and control 0pg/ml (range 0 – 39.4) (p=0.001). Plasma VEGF at a cut off value of 250pg/ml was determined to have a sensitivity of 100%, specificity of 77.8%, a PPV of 81.8% and a NPV of 100% for determining neoplastic transformation. Serum VEGF at a cut off value of 25pg/ml was determined to have a sensitivity of 88.9%, specificity of 100%, a PPV of 100% and a NPV of 90% for determining neoplastic transformation. Both plasma and serum VEGF concentrations can be used to differentiate between non-neoplastic and neoplastic spirocercosis. Plasma VEGF concentrations were higher than serum VEGF concentrations, contrary to what is reported in literature. Both plasma and serum VEGF concentrations can, therefore, potentially be used for diagnosis of neoplastic vs. non-neoplastic cases in canine spirocercosis. There is a need to perform more studies to determine cut-off concentrations that would maximize the sensitivity and specificity for determining neoplastic transformation in canine spirocercosis as well as to determine the role of VEGF in the pathogenesis of the neoplastic transformation. Copyright / Dissertation (MMedVet)--University of Pretoria, 2012. / Companion Animal Clinical Studies / unrestricted

Objective To compare the anaesthetic and cardiopulmonary effects of alfaxalone in comparison to propofol when used for total intravenous anaesthesia (TIVA) during ovariohysterectomy in dogs. Animals Fourteen healthy female crossbred dogs between 6 months and 5 years, with body weight between 16 - 42 kg. Methods All dogs were premedicated with acepromazine 0.01 mg/kg and morphine 0.4 mg/kg subcutaneously. Anaesthesia was induced and maintained with either Group 1- propofol (6 mg/kg followed by 0.3-0.5 mg/kg/min intravenously) or Group 2 alfaxalone (2 mg/kg followed 0.10-0.12 mg/kg/min intravenously). Quality of induction and recovery were determined. Dogs were spontaneously breathing 100 % oxygen. Respiratory and cardiovascular parameters were measured: Respiratory rate (RR), end tidal CO2 (ETCO2), tidal volume (TV). Heart rate (HR), systolic (SAP), diastolic (DAP), and mean arterial blood pressure (MAP). Arterial blood samples were collected during and after the surgery to determinate arterial PH, PaCO2, PaO2. Results Smooth and rapid induction followed by satisfactory maintenance and good recovery quality was observed with both anaesthetic agents. Cardiopulmonary effects were similar for both groups with notable respiratory depression and fair hemodynamic parameters. Conclusions and Clinical Relevance The administration of alfaxalone used as TIVA in premedicated dogs produced satisfactory anaesthesia with the same quality as that produced by propofol during ovariohysterectomy. Hypoventilation was the most prominent adverse effect from both anaesthetic agents suggesting a need for ventilatory support during prolonged TIVA periods with either anaesthetic agent. / Dissertation (MSc)--University of Pretoria, 2010. / Companion Animal Clinical Studies / unrestricted

Laboratory serum biochemical tests are regarded by the Liver Study Group (LSG) of the WSAVA as an essential component of any liver investigation. The LSG categorised liver disease into four groups: vascular disorders, biliary disorders; parenchymal disorders and neoplasia. The laboratory tests that evaluate the liver have three categories. The cytosolic enzymes assess hepatocellular integrity; the cholestatic or inducible enzymes assess the biliary tree, liver excretory pathways and possible enzyme induction. The third category is the liver function tests which assess overall hepatic functional mass and portovascular integrity. The liver function tests commonly used include plasma ammonia concentration, serum bile acid concentrations and various tests that evaluate the uptake and conjugation of metabolites by the liver. Uric acid was once used as a liver test in the late 1950’s early 1960’s. Physiologically, uric acid is an attractive candidate for a liver function test. In most mammalian species serum uric acid levels only increase to the levels encountered in humans when there is hepatic dysfunction. Uric acid fell out of favour as a liver function test following the publication of two studies and one case report in the late 1950’s. The differences between hepatocellular integrity tests, cholestatic tests and tests of liver function were not fully understood at that time. The authors unfairly compared uric acid, essentially a liver function test, to a test of cholestasis. In addition the authors had very vague inclusion criteria for their liver disease cases. Despite the short-comings in these studies several prominent reference texts have since perpetuated their findings and uric acid fell out of the reckoning as a test of liver function. Many tests of liver function have been used over the years. Dynamic function tests have gained popularity again. Plasma ammonia concentration is a very reliable test of liver function but has very stringent sample-handling requirements which often make its application in the average clinic setting impractical. Serum bile acid concentrations, while not as sensitive or specific for portovascular shunting as ammonia, are widely regarded as the best test of overall liver function, especially with respect to non vascular-associated liver disease. However bile acid assays are not widely available in South Africa resulting in delays in turn-around times. In today’s climate of ever increasing costs, and demand for rapid turn around times, it would be very useful to veterinarians if a simple, rapid, cheap and robust assay could be found for evaluating functional hepatic mass. Uric acid would seem to have this potential and it is performed by most medical laboratories. In this study the serum uric acid concentrations and concentration of bile acids of a control group of normal dogs was used to compare to those in three other groups of dogs. Two of these groups had liver disease, and the third was a renal disease group. The one group of liver disease was comprised of dogs with congenital vascular anomalies while the second liver disease group was made up of dogs with various parenchymal liver diseases. Serum bile acid concentrations in the four groups were compared to the serum uric acid levels to assess the utility of uric acid as a test of liver function; and to measure the affects of diminished renal function on serum uric acid concentrations. There were significant differences in the serum bile acid concentrations between the two liver disease groups and the non-liver disease groups. Uric acid concentrations between all four groups did not differ significantly however. Serum uric acid was elevated in dogs with renal impairment. Therefore the findings in this study indicate that uric acid cannot be used as a test of liver function and is not comparable to serum bile acids in this regard. Copyright / Dissertation (MMedVet)--University of Pretoria, 2009. / Companion Animal Clinical Studies / unrestricted

Trauma of diverse origins is a common reason for presentation of pets for treatment. It is often difficult clinically to objectively measure the severity of any trauma to an animal. One approach is to measure the changes in the various serum parameters which are known to alter in response to trauma or inflammation. If the changes over time of relevant and easily measurable parameters can be established under two controlled but different conditions of surgical trauma, it may provide the foundation for evaluating their future use in establishing the severity of trauma in a patient. A prospective study was performed on animals presented to the Onderstepoort Veterinary Academic Hospital for either thoracolumbar disc disease or for elective ovariohysterectomy. The two surgical procedures chosen for the study involved significant surgical trauma, particularly to muscle, in the case of thoracolumbar decompression and relatively minor surgical trauma in the case of ovariohysterectomy. Serial evaluation of creatine kinase (CK) and C-reactive protein (CRP) were performed both pre- and post-operatively on two sets of patients derived from the two surgical categories. CK is an enzyme found predominantly in skeletal muscle and significantly elevated serum activity is largely associated with muscle damage. CRP is an acute phase protein which shows elevated serum concentration in response to a broad range of inflammatory stimuli. Analysis of the data showed a very wide range of results at each time point for both CK and CRP. There were no significant differences between the two surgical groups for either analyte preoperatively. Thereafter CK results were markedly and significantly different between the two groups. CRP results were very similar in the two groups with no statistical difference at any time point. The results of this study suggest that the evaluation of CK and CRP at any one time point in a traumatized animal is of limited value. However the evaluation of the trend of these two analytes, even over a relatively short time period, may allow for useful prognostication in clinical cases. / Dissertation (MMedVet)--University of Pretoria, 2008. / Companion Animal Clinical Studies / unrestricted

Brucella canis causes canine brucellosis in dogs inducing mainly contagious abortion. Diagnosis of B. canis is based on bacterial isolation that is timeconsuming and inconsistent; serological tests (more than one test) that is ambiguous and lacks specificity; and PCR that may lack sensitivity as bacteraemia may not be constant. Since bacteraemia of B. canis develops 7-30 days after infection, often resulting in a sustained bacteraemia, PCR was investigated for the detection of B. canis in whole blood of dogs. The PCR sensitivity was validated to detect 3.8 fg Brucella DNA mixed with dog DNA as well as 1 x 102 cfu/ml B. canis in dog blood (mock infection) using primers (ITS66 and ITS279) that amplifies the 16S-23S ribosomal DNA intergenic spacer (ITS) region. The PCR assay for the detection of B. canis in whole blood samples was compared with bacterial isolation, serological tests, which include the rapid slide agglutination test (RSAT), 2-mercaptoethanol RSAT (2ME-RSAT) and imunochromatographic assay (ICA). These techniques were used to test 56 dog samples obtained from the Michangulene and Mafavuca villages at the municipality of Changalane, in District of Namaacha in Maputo, Mozambique for B. canis. No B. canis was isolated from dog blood using the classical microbiology isolation and PCR. A sample was only presumed positive if both the 2ME-RSAT and ICA tested positive. None of the samples in this study tested positive using this criterion for serological testing. Results of this study indicated that B. canis was not present in the 56 dogs sampled in the Maputo region of Mozambique using bacteriology, PCR and serological tests (RSAT, 2ME-RSAT and ICA). Due to the discrepancy between serological tests we cannot conclude that B. canis is not present in the Maputo region of Mozambique. In future the accuracy of the serological tests, bacteriology and PCR assay should be assessed using experimentally infected B. canis dogs over a period followed by a surveillance study in Mozambique that includes urine, semen and blood samples collected from dogs. / Dissertation (MSc)--University of Pretoria, 2010. / Veterinary Tropical Diseases / Unrestricted

Inconsistent use of nomenclature in different canine malignant lymphoma (CML)classification systems, which lead to incorrect diagnosis and prognosis, necessitated a retrospective study of 103 cases of CML. Histological classification was done according to the Working Formulation, on H&E sections, after standard processing. Immunophenotyping, using CD3 (T cell) and CD79a (8cell) markers, was carried out on the same sections. Intermediate grade lymphomas were the largest category (49.5%), with 16.5%high grade lymphomas. More than half (53.3%) of the lymphomas were of 8 cell immuno phenotype, and 36.5% were T cell lymphomas. Only 9.7% of the total number of lymphomas exhibited double negative staining. Only two categories, the immunoblastic and medium-sized macro nucleolated (MMC) category (Fournel-Fleury et al.). exhibited constant (8 cell) immunophenotype. All the other categories exhibited mixed immunophenotype. The Working Formulation, with omission of the follicular tyoes (due to the rarity thereof in CML) and addition of the MMC category and immunophenotyping, is best for classifying CML. / Dissertation (MMed Vet (Pathology))--University of Pretoria, 1999. / Anatomy and Physiology / Unrestricted

No abstract / Dissertation (DVSc)--University of Pretoria, 1953. / Companion Animal Clinical Studies / DVSc / Unrestricted

The occurrence of tick-borne pathogens in dogs on communal land in Botswana was studied using Reverse Line Blot (RLB). Eighty blood samples were collected from dogs that underwent a spay and neuter program in Maun, Botswana. These were sent to the Department of Veterinary Tropical Diseases, University of Pretoria, and were stored at the Molecular Laboratory. DNA was extracted from the samples followed by the Polymerase Chain Reaction (PCR) and the RLB. Six samples were found to be positive for Ehrlichia canis. Two of the samples were positive for a concurrent infection of E. canis and Ehrlichia ruminantium. There was one sample that was positive for the non-pathogenic Ehrlichia sp. Omatjenne. Although six samples were positive for the Babesia/Theileria catch-all probe, none hybridised with any of the species-specific probes. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Veterinary Tropical Diseases / unrestricted

This study examined the food interactions between Utah prairie dogs (Cynomys parvidens, Allen) and cattle (Bos taurus), During 1974 and 1975, three prairie dog colonies near Panguitch, Utah, were studied intensely: "Oldfield" was chosen to represent colonies near fields of alfalfa (Medicago sativa); "Lowercrested" was chosen to represent colonies below 2,200 meters above sea level (a. s. 1.) which were not near alfalfa, and "Uppercrested" was chosen to represent colonies above 2,200 meters a.s.l. which have been planted with crested wheatgrass. Visual observations were made of Utah prairie dogs to determine their diets. Livetrapping of prairie dogs provided data for estimates of population sizes and animal weights, which were used to calculate forage requirements. Cattle diets and forage intake per individual were derived from the literature. Much more forage was available to prairie dogs than to cattle. About 80 percent of the forb phytomass ingested by prairie dogs at Uppercrested never would have become available to cattle. Prairie dogs foraged more selectively than cattle are capable of doing. Neither animal showed a general dietary preference toward either grasses or forbs: each plant life form contained bath preferred and avoided species. Bath animals had a low preference for shrubs. Oldfield's area tripled between 1971 and 1974, but Uppercrested did not expand. Between 1 June, 1974, and 1 June, 1975, Oldfield's population increased from about 42 to 70 adult prairie dogs, and the colony's area increased proportionately; however, Uppercrested's population appeared to decline from approximately 22 to 19 adults. The dissimilar expansion rates, at least between 1974 and 1975, probably were due to differences in behavior, forage availability, nutrition, and predation. Oldfield's prairie dogs gained weight much faster than did Uppercrested's animals. Thus, the average number of active Utah prairie dogs ingesting as much forage as a cow and calf from March through October (prairie dogs fed little during other months) was 410 at Oldfield, compared to 500 at Uppercrested. Numbers concerning total utilization may be even higher: prairie dogs waste little vegetation, but cattle probably trample much. On the other hand, prairie dogs clip closer to the ground and earlier in the growth season than do cattle; consequently, prairie dogs may cause a greater reduction in primary production for the same amount of forage intake. Population densities of prairie dogs in late June, one month after the young first emerged, were 35/ha at Oldfield, 16/ha at Lowercrested, and less than 2.3/ha at Uppercrested. Prairie dogs used over 70 percent of the primary production of perennial herbage at Oldfield and about 10 percent of it at Lowercrested. Uppercrested's prairie dogs used approximately 3 percent of the primary production of crested wheatgrass, a preferred forage. Within any one year, cattle probably rarely reduce population s of Utah prairie dogs, and possibly may increase populations in colonies with high primary production. Prairie dogs apparently have reduced the primary production of perennial herbage at bath Oldfield and Lowercrested. Vegetational canopy coverage was greater on mounds than off mounds in the low use portion of Uppercrested. Heavy grazing by livestock in the past probably has eliminated much Utah prairie dog habitat: swales have been destroyed and early spring forage has been reduced.