Doctor of Philosophy / Department of Diagnostic Medicine and Pathobiology / Brad J. White and Robert L. Larson / Bovine respiratory disease (BRD) is the most costly disease of cattle in US feedyards and diagnosis based on clinical signs of illness is challenging. Over the course of five independent studies we evaluated the precision of multiple observers assigning clinical illness scores (CIS) to calves with induced Mycoplasma bovis pneumonia. We also evaluated the accuracy of CIS in relation to lung lesions at necropsy. Agreement among observers over all five studies was slight ({kappa]= 0.16; 95% confidence interval, 0.10 to 0.24) and ranged from 0.10 to 0.21 for individual trials. The accuracy of CIS varied based on the pulmonary consolidation score chosen to represent a truly ill animal. Inflammation associated with BRD can lead to significant pulmonary damage and reduced lung function. Treatment for BRD frequently involves antimicrobial administration and occasionally non-steroidal anti-inflammatory drugs. We evaluated how calves experimentally challenged with Mannheimia haemolytica respond to treatment with flunixin meglumine, alone or in combination with the antimicrobial florfenicol. Individual calf response to bacterial pneumonia was highly variable in this study. None of the changes in serum biomarkers, CBC or chemistry parameters provided reliable indicators of the pulmonary inflammation associated with the mild severity of bronchopneumonia in our study. Metaphylaxis is frequently administered to manage the risk of BRD within cohorts of cattle. We evaluated the impact of metaphylactic antimicrobial administration 10 days prior to experimental Mannheimia haemolytica inoculation to mitigate pulmonary lesions. We found that calves receiving tildipirosin had less lung damage and fewer clinical signs of illness compared to calves treated with tulathromycin or saline. Finally, the ability to predict those animals that would not finish the production cycle normally would provide benefits in effectively managing cattle. We evaluated the ability of classification algorithms to accurately predict an individual calf’s outcome based on data available at first identification of and treatment for BRD. We found accuracy of classifiers was dependent on the data recorded by the feedyard and there are sub-groups of calves within feedyard populations where classifiers were highly accurate. These data suggest the importance of pairing the proper classifier with the data available.

Cough is common but has been under-researched. In tuberculosis cough is probably of particular relevance in transmitting infection. This thesis explores several interlinking areas. Regarding how best to measure cough, coughs are shown to be recognizable to the human ear, but automated cough monitors can disagree with auditory cough counting. A novel approach to testing cough reflex sensitivity is described, E62.5. There was no evidence to support the hypothesis that cough has unique characteristics in tuberculosis, in terms of symptoms, frequency and clustering. A significant reduction of cough frequency in tuberculosis is demonstrated overnight. Clinical correlates of 24hour cough frequency were explored; female sex in unexplained chronic cough, and sputum smear status in tuberculosis were important, and possibly transfer factor in pulmonary fibrosis and duration of symptoms prior to treatment in COPD exacerbations. Cough frequency correlated poorly with symptoms. There seem to be both generic and disease-specific mechanisms associated with cough. This was further suggested by a faster reduction in cough frequency with treatment in pneumonia than in acute asthma and COPD exacerbations, correlating with C-reactive protein decline only in pneumonia. A serial reduction in 24-hour cough frequency in tuberculosis during the whole course of treatment was demonstrated, a potentially novel approach to measuring treatment response. The role of genetic polymorphism in the cough receptor gene TRPV1 was explored, but, at least in chronic cough was not demonstrated to predict coughing. Regarding the infectiousness of coughs, an airborne particle counter was shown not to be sensitive enough for measuring droplets released during coughing in room air. However, I demonstrate for the first time a significant association between 24-hour cough frequency in TB and household infection. This work has set a foundation for the further investigation of the mechanisms, processes and patterns of coughing with respect to tuberculosis transmission and other contexts.

Orientador: Roberto Calderon Gonçalves / Banca: Rogério Martins Amorim / Banca: Simone Biagio Chiacchio / Banca: Alice Maria Melville paiva Della Libera / Banca: Giovana Wingeter Di Santis / Resumo: A expansão econômica da ovinocultura acarreta no aumento do número de animais mantidos em confinamento e seu maior trânsito entre as propriedades. Com isso há aumento dos índices de doenças respiratórias nessa espécie, que estão entre as enfermidades que ocasionam maiores perdas econômicas em rebanhos de vários países. Grande parte das doenças respiratórias de mortalidade elevada e sintomatologia clínica evidente está associada a infecções por Mannheimia (Pasteurella) haemolytica. Entretanto, outras enfermidades também acometem os ovinos e são pouco definidas etiológica e morfologicamente, especialmente as de etiologia viral. Os vírus têm sido incriminados como agentes precursores e agravantes quando em associação com infecção bacteriana secundária. Os métodos mais utilizados para identificação viral são a sorologia, isolamento viral, teste de vírus neutralização e reação em cadeia pela polimerase. Contudo, essas técnicas apresentam limitações quanto ao tempo de execução e a necessidade de equipamentos dispendiosos. Com a necessidade da detecção rápida de antígenos virais, métodos como imunofluorescência e ensaios imunoenzimáticos vem sendo mais estudados no diagnóstico de agentes etiológicos. A imunoistoquímica é uma opção para a identificação de diversos agentes etiológicos e vem sendo amplamente estudada nos casos de enfermidades respiratórias, devido a facilidade na execução e não necessitar equipamentos dispendiosos nem técnicas trabalhosas para armazenamento de amostras. Neste contexto, o propósito deste estudo foi avaliar ovinos com comprometimento de vias aéreas anteriores e processos broncopulmonares, detectados no exame clínico e exame histopatológico, e correlacionar os achados com a sorologia, citologia de vias aéreas anteriores e posteriores, com a imunoistoquímica para os Vírus sincicial respiratório... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The economic expansion of sheep breeding cause an increase in the number of animals kept in confinement and increased traffic between these properties, increasing the rates of respiratory diseases in this species, which are among the diseases that cause major economic losses in herds in several countries. Much of respiratory diseases and high mortality evident clinical symptoms are associated with infections by Mannheimia (Pasteurella) haemolytica, however, other diseases also affect sheep and are poorly defined etiology and morphology, especially viral diseases. Viruses have long been incriminated as agents precursors and aggravating when combined with secondary bacterial infection. The methods used for viral identification are serology, virus isolation, virus neutralization test, polymerase chain reaction. However, these techniques have limitations as to time of execution and the need for expensive equipment. With the need for rapid detection of viral antigens, methods such as immunofluorescence and enzyme immunoassays has been most studied in the search for etiologic agents. Immunohistochemistry is an option for the identification of other agents and has been widely studied in cases of respiratory illnesses due to ease of execution and does not require expensive equipment or laborious techniques for sample storage. In this context, the purposes of this research was to evaluate sheep with involvement of upper airways and bronchopulmonary cases, detected on clinical examination and histopathology, and correlate the findings with serology, cytology airways before and after, and immunohistochemistry for Virus Respiratory Syncytial and Parainfluenza virus. Was detected by serology 27.5% for the BIS-3 and 40% for BRSV positive samples. There was a predominance of interstitial pneumonia type (56.7%) and immunohistochemistry detected the presence of BPI-3 antigens in 13.3% and 20.0% ...(Complete abstract click electronic access below) / Doutor

The objectives of this project were: 1) to determine if live animal lung biopsy could be used to characterize early pathologic changes in the bovine lung associated with bovine respiratory disease (BRD), 2) determine if specific infectious respiratory pathogens can be identified in association with early pathological changes, and 3) determine whether pulmonary pathology characterized by live animal lung biopsy at arrival and at the time of initial BRD diagnosis was associated with health and production outcomes of feedlot steers in a commercial feedlot.<p> A live animal percutaneous lung biopsy technique was developed to obtain a lung sample from the right middle lung lobe in intercostal space (ICS) 4 using a Bard® Magnum® reusable biopsy instrument and a modified 4-mm (8g) biopsy needle. The lung biopsy procedure was limited to 2 attempts per biopsy time. In the technique development, 34 animals chronically affected with BRD were utilized, 20 animals in the preliminary development followed by 14 additional animals in a commercial feedlot setting. The technique resulted in 1 fatality of 34 steers (2.9%) and lung parenchyma was harvested in 19 of 34 steers (55.9%) chronically affected with BRD. In addition, in the commercial feedlot setting this procedure was determined to take about 20 minutes per animal.<p> The final study was performed on one hundred feedlot steers considered at high risk of developing BRD from twenty pens within a commercial feedlot. Study animals were enrolled in three different groups: sick on arrival (ARR-SA) consisting of 27 study animals and 13 matched control animals; pen pulls with no fever (PP-NF) consisting of 14 study animals and matched 7 controls; and pen pulls with an undifferentiated fever (PP-UF) consisting of 26 study animals and 13 matched controls. Live animal percutaneous lung biopsies were collected from the right middle lung lobe at 3 different times within the first 30 days of the feeding period, about 2 weeks apart. All samples were histopathologically evaluated and were assessed for the presence of <i>Mycoplasma bovis</i>, <i>Mannheimia haemolytica</i>, Histophilus somni and bovine viral diarrhea virus with immunohistochemistry.<p> A total of 295 lung biopsies were performed yielding 210 (71.2%) lung samples that were sufficient for histopathological evaluation. A histopathology score was awarded to each biopsy based on certain histopathological lesions being present. Only 20 lung biopsy samples from 19 animals received a histopathology score (ie, pulmonary lesions were present) with the most common score being a 1 (maximum score is 20). There were too few lung biopsy samples with a histopathology score to reveal any association with subsequent health events.<p> Immunohistochemistry (IHC) was performed on all lung biopsies recovered yielding one lung sample to be positive for both <i>Mannheimia haemolytica</i> and <i>Mycoplasma bovis</i> from the PP-UF group. There were too few positive samples to reveal any association between IHC and histopathology score.<p> A post mortem evaluation was performed by a study veterinarian on all study animals who died or were humanely euthanized due to poor treatment response. In this study only 4 steers died or were euthanized due to poor treatment response and 3 control steers were humanely euthanized. There were too few animals to reveal any association between histopathology score and post mortem diagnosis.<p> On entry into the feedlot, weights between ARR-SA and the PP-UF and PP-NF groups were significantly different (p<0.05). This is likely an effect of the different processing groups of cattle. At study allocation, the body weights of ARR-SA and PP-UF, PP-UF and their matched controls, and PP-NF and their matched controls were also significantly different (p<0.05). This is likely due to the PP-UF and PP-NF groups experiencing illness for a longer period of time resulting in greater weight loss than the ARR-SA animals as well as the control animals, who were not clinically sick.<p> The live lung biopsy procedure utilized in this study did not appear to cause any long lasting adverse effects as the BRD case fatality rates from the study animals were comparable to the overall case fatality rates reported by the feedlot for fall placed calves. In fact, the study animals experienced a decreased fatality rate compared to the feedlots overall fatality rate. This may be due to the study animals inadvertently being monitored more closely as the pen checkers were aware of and participating in the study. On post mortem evaluation there was no evidence of adhesions at the biopsy site. This procedure was performed on 134 feedlot steers resulting in only 2 acute deaths as a direct result of the live animal percutaneous lung biopsy procedure.<p> The results of this study indicate that live animal, percutaneous lung biopsy can be performed safely on feedlot steers in a commercial feedlot with few clinical side effects. In this study there were only 2 fatalities in 134 steers (1.5%) due to the biopsy procedure or 2 fatalities per 349 sampling times (0.6%) This technique did not prove useful either as a diagnostic tool for the determination of early lung pathology in BRD or as prognostic indicator for health and production outcomes. However, this lung biopsy technique may be a useful diagnostic tool for chronic pneumonia assessment.

The objectives of this project were: 1) to determine if live animal lung biopsy could be used to characterize early pathologic changes in the bovine lung associated with bovine respiratory disease (BRD), 2) determine if specific infectious respiratory pathogens can be identified in association with early pathological changes, and 3) determine whether pulmonary pathology characterized by live animal lung biopsy at arrival and at the time of initial BRD diagnosis was associated with health and production outcomes of feedlot steers in a commercial feedlot.<p> A live animal percutaneous lung biopsy technique was developed to obtain a lung sample from the right middle lung lobe in intercostal space (ICS) 4 using a Bard® Magnum® reusable biopsy instrument and a modified 4-mm (8g) biopsy needle. The lung biopsy procedure was limited to 2 attempts per biopsy time. In the technique development, 34 animals chronically affected with BRD were utilized, 20 animals in the preliminary development followed by 14 additional animals in a commercial feedlot setting. The technique resulted in 1 fatality of 34 steers (2.9%) and lung parenchyma was harvested in 19 of 34 steers (55.9%) chronically affected with BRD. In addition, in the commercial feedlot setting this procedure was determined to take about 20 minutes per animal.<p> The final study was performed on one hundred feedlot steers considered at high risk of developing BRD from twenty pens within a commercial feedlot. Study animals were enrolled in three different groups: sick on arrival (ARR-SA) consisting of 27 study animals and 13 matched control animals; pen pulls with no fever (PP-NF) consisting of 14 study animals and matched 7 controls; and pen pulls with an undifferentiated fever (PP-UF) consisting of 26 study animals and 13 matched controls. Live animal percutaneous lung biopsies were collected from the right middle lung lobe at 3 different times within the first 30 days of the feeding period, about 2 weeks apart. All samples were histopathologically evaluated and were assessed for the presence of <i>Mycoplasma bovis</i>, <i>Mannheimia haemolytica</i>, Histophilus somni and bovine viral diarrhea virus with immunohistochemistry.<p> A total of 295 lung biopsies were performed yielding 210 (71.2%) lung samples that were sufficient for histopathological evaluation. A histopathology score was awarded to each biopsy based on certain histopathological lesions being present. Only 20 lung biopsy samples from 19 animals received a histopathology score (ie, pulmonary lesions were present) with the most common score being a 1 (maximum score is 20). There were too few lung biopsy samples with a histopathology score to reveal any association with subsequent health events.<p> Immunohistochemistry (IHC) was performed on all lung biopsies recovered yielding one lung sample to be positive for both <i>Mannheimia haemolytica</i> and <i>Mycoplasma bovis</i> from the PP-UF group. There were too few positive samples to reveal any association between IHC and histopathology score.<p> A post mortem evaluation was performed by a study veterinarian on all study animals who died or were humanely euthanized due to poor treatment response. In this study only 4 steers died or were euthanized due to poor treatment response and 3 control steers were humanely euthanized. There were too few animals to reveal any association between histopathology score and post mortem diagnosis.<p> On entry into the feedlot, weights between ARR-SA and the PP-UF and PP-NF groups were significantly different (p<0.05). This is likely an effect of the different processing groups of cattle. At study allocation, the body weights of ARR-SA and PP-UF, PP-UF and their matched controls, and PP-NF and their matched controls were also significantly different (p<0.05). This is likely due to the PP-UF and PP-NF groups experiencing illness for a longer period of time resulting in greater weight loss than the ARR-SA animals as well as the control animals, who were not clinically sick.<p> The live lung biopsy procedure utilized in this study did not appear to cause any long lasting adverse effects as the BRD case fatality rates from the study animals were comparable to the overall case fatality rates reported by the feedlot for fall placed calves. In fact, the study animals experienced a decreased fatality rate compared to the feedlots overall fatality rate. This may be due to the study animals inadvertently being monitored more closely as the pen checkers were aware of and participating in the study. On post mortem evaluation there was no evidence of adhesions at the biopsy site. This procedure was performed on 134 feedlot steers resulting in only 2 acute deaths as a direct result of the live animal percutaneous lung biopsy procedure.<p> The results of this study indicate that live animal, percutaneous lung biopsy can be performed safely on feedlot steers in a commercial feedlot with few clinical side effects. In this study there were only 2 fatalities in 134 steers (1.5%) due to the biopsy procedure or 2 fatalities per 349 sampling times (0.6%) This technique did not prove useful either as a diagnostic tool for the determination of early lung pathology in BRD or as prognostic indicator for health and production outcomes. However, this lung biopsy technique may be a useful diagnostic tool for chronic pneumonia assessment.

Respiratory disease is an important cause of wastage in the Australian horse racing industry and viruses are frequently suspected as aetiological agents of respiratory disease or poor performance by clinicians and trainers but confirmation is seldom attempted. This thesis deals with the potential role of equine herpes virus types 1, 2, 4 and 5 in upper respiratory disease and poor performance in horses in Western Australia. The methodology selected for the identification of equine herpes viruses in tissues of horses was polymerase chain reaction (PCR) and therefore individual PCR assays were developed for the detection of each herpes virus, and then a nested multiplex PCR was developed to detect all four viruses. There was good correlation between the multiplex PCR for the detection of EHV and the detection of virus by isolation in cell culture, although a combination of the 2 techniques provided greater sensitivity than either technique alone. The multiplex PCR described appeared equally sensitive as specific PCR assays using a single set of primers for each individual virus but reduced labour and reagent costs. As latency is a well recognised phenomenon in the equine herpes viruses and the horse is subjected to a number of stresses which might induce reactivation of latent infections, it was hypothesised that there would be a background level of replication of the equine herpes viruses in clinically normal horses. Nasal swabs and peripheral blood leukocytes (PBL) were obtained from 282 clinical normal horses and examined for EHV. The results clearly demonstrated the widespread occurrence of EHV in the clinically healthy horses. The rate of detection of different types of EHV varied, as did the prevalence in young and adult horses. The most common EHV detected was EHV5: in 83.2% of 131 of horses <2 years of age; in 40% of horses >2 years of age. A prospective clinical study was conducted whereby respiratory tract samples and PBL from adult horses with respiratory disease and/or poor performance were examined for equine herpes viruses; the aim was to determine a possible association between equine herpes virus infection and respiratory disease and/or poor performance. The relative incidence of factors identified in the history, signalment, physical and laboratory evaluation of horses in the study population was compared between horses from which EHV was identified in respiratory samples and horses negative for equine herpes virus. The results indicated that equine herpes viruses were important causes of respiratory disease in the study population, and that haematological and cytological data were a poor indicator of such equine herpes virus infection. The occurrence of equine herpes virus in nasal swabs and PBL of weaned or unweaned foals from Thoroughbred breeding establishments was determined and provided data on the occurrence of EHV in association with respiratory disease. EHV5 was detected in nasal swabs and/or PBL at a high prevalence rate in healthy foals and yearling horses but its occurrence was not associated with clinical signs of respiratory disease. In contrast, EHV2 was detected more commonly in nasal swabs and/or PBL from foals with respiratory disease than in similar samples from healthy horses. Experimental infection of 8 horses with EHV2 was attempted and induced clinical signs of respiratory disease, but less severe than observed in the epidemiological studies. The results suggested that EHV2 is associated with mild upper respiratory tract infection in young horses.

Master of Science / Department of Diagnostic Medicine/Pathobiology / Alison P. Adams / Bovine respiratory disease (BRD) is the most common and costly disease affecting cattle in the world today. The disease was first described in the late 1800s and is one of the most extensively studied diseases of livestock. BRD accounts for 65 - 80% of the morbidity and 45 - 75% of the mortality in some feedlots. Outbreaks typically occur around 10 days after transportation with the majority of deaths occurring within the first 45 days of arrival. Bacterial pathogens, physiologic stressors, and concurrent viral infections are all important factors causing BRD; other factors include seasonality, heritability, and breed tolerance. Diagnostic and treatment measures are continually being critiqued and researched. Even with continued research and the administration of antibiotics, BRD still continues to be a problem for the beef industry. Remote early detection and previous calf history are two resources that can help feedlots diagnose the disease earlier, or prevent it entirely. Feeding behavior and physical exams of the calves can also aid in early detection. New antibiotics and treatment methods have been developed, but the BRD problem still exists. Since the disease is most problematic in feedlot cattle, treatment of a large number of cattle in this setting can be costly, and often, performance and carcass traits are also affected. New preventative measures will be crucial to the industry with the continued problems and consequences of BRD. Improved treatment options and enhanced diagnostic tools will also be imperative for the control and treatment of BRD in the future.

No description available.

The study objective was to evaluate the effects of vaccination (respiratory and clostridial vaccination or no vaccination) and deworming (fenbendazole and levamisole or no deworming) of high risk stocker calves on-arrival on health and growth performance. Eighty sale barn origin calves were purchased three separate years (n=240) from local order buyer. Steers (n=61) and bulls (n=179) were received over three days (d -3 to -1). On d 0 calves were stratified by arrival BW and FEC into 20 pens of 4 calves each, and treatment was applied to pens in 2 x 2 factorial. Vaccination increased the likelihood of BRD 1.7 times (P=0.07) versus calves not vaccinated. Vaccination did not affect gain, but calves receiving dewormer had greater ADG than those not receiving dewormer. Calves that arrived uncastrated or with high fever (≥40.0°C) gained less and were 1.7 and 4.3 times more likely (P<0.10) to be treated for disease, respectively.

Bovine respiratory disease (BRD) complex is a multiactorial disease syndrome that results from various individual contributions and interactions of pathogen, host, and environmental/management factors. Despite the efforts in research, prevention and treatment, BRD remains a leading cause of economic loss in the cattle industry. While advances in therapeutics and new vaccines have been developed over the past 20 – 25 years, the incidence of respiratory disease does not appear to be on the decline, rather it is appears to be increasing. While bacterial and viral pathogens, and various stressors associated with BRD have been characterized, there are no animal models that can reproduce similar presentation of symptoms observed for BRD in the industry. Based on the etiology of BRD, a series of projects were designed to provide a better understanding of the individual and multiple contributions for the factors associated with the complex. It is believed that the viral pathogens or stressors can suppress immune defenses allowing opportunistic bacteria the ability to colonize and cause an infection. Therefore, trials investigating the individual contribution that varying doses of infectious bovine rhinotracheitis virus and transportation stress have on cattle were conducted. A final project investigating the combination effect of the bacterial pathogen M. haemolytica and activation of the hypothalamic-pituitaryrenal axis to elicit glucocorticoid release was evaluated. Ultimately, the research projects were designed to build upon each other to understand each component in the etiology of this disease.