This dissertation focuses on the effect of breeding on the myocardium of stallions using cardiac troponin I (cTnI) as the preferred blood biomarker for detection of myocardial cell injury. Haematological, echocardiographic and heart rate (HR) parameters are also reported. Fourteen clinically healthy phantom-trained stallions were assessed. Cardiac troponin I concentration was determined pre-semen collection and at 4, 6, 12 and 24 hours following semen collection. Predictors that were measured included mean HR during each stage of semen collection, maximum HR, area under the curve for HR and fractional shortening (FS). Pre-semen collection cTnI concentrations were within reported reference ranges for all stallions. Following semen collection, cTnI concentration was significantly increased at 4 and 6 hours post-semen collection. Results also suggest that the HR of stallions peak during mounting of the phantom. Five stallions failed to show an expected increase in FS immediately post-semen collection. No association was identified between the measured predictors and increased cTnI concentration. This study concluded that cTnI concentration may increase in stallions following semen collection although the clinical significance of this observed increase in healthy stallions is unclear without histopathological evaluation of the myocardium. No conclusion regarding FS immediately post-semen collection could be drawn from results in this study. The research reported in this dissertation can serve as a reference for future studies investigating cTnI concentrations in stallions. / Dissertation (MSc)--University of Pretoria, 2010. / Companion Animal Clinical Studies / unrestricted

This dissertation describes the epidemiological investigation and management of the first outbreak of Contagious Equine Metritis (CEM) reported in South Africa. In addition, the subsequent implementation of a nationwide quantitative polymerase chain reaction (qPCR)- based stallion screening programme and traceback of exposed animals to define the spread of CEM in South Africa is described. The first South African outbreak of CEM caused by the bacterium, Taylorella equigenitalis was reported on the 9th May 2011 to the World Health Organisation for Animal Health (OIE). The outbreak was recognized subsequent to the importation of a young Warmblood stallion from Germany. The outbreak initially appeared confined to a single index property (focus property), an equine breeding facility in Midrand, Gauteng, South Africa with a single confirmed case of transmission involving the index stallion and a Thoroughbred mare. The initial response was rapidly instituted following the suspicion of T. equigenitalis on the index property. This included an inspection of the index property and its records. A riskclassification of in-contact animals allocated them to “high,” “moderate” or “low”-risk categories. The classification was dependent on the temporal relationship of their presence on the index property relative to the period of residence of the index cases. After T. equigenitalis infection was confirmed from both index cases, the breeding facility was placed under state– administered quarantine and all exposed mares and the index cases were transferred to a quarantine facility. The animals were re-tested by genital swabbing for bacterial culture following a standard protocol according to internationally-accepted practice (OIE Terrestrial Manual on Contagious Equine Metritis). Additional duplicate swabs were obtained for real time qPCR. None of the mares were shown to be positive on either bacterial culture or qPCR. All animals were however treated according to an accepted protocol for T. equigenitalis infection (Luddy and Kutzler, 2010, UK Horseracing Betting Levy Board (HBLB) Code of Practice, 2011). All stallions that had been present on the index property and undergone semen collection on the same day as the index stallion were classified as “moderate risk” and were similarlytested. This identified two additional T. equigenitalis-positive stallions, which were confirmed on bacterial culture (World Organization for Health (OIE) Manual of Diagnostic Tests and Vaccines for Terrestrial Animals (Chapter 2.5.1, Contagious Equine Metritis version adopted 20/10/2011) and which were subsequently quarantined and successfully treated. Following recognition of this outbreak, the Department of Agriculture, Forestry and Fisheries (DAFF) in consultation with the Equine Research Centre (ERC) of the Faculty of Veterinary Science at the University of Pretoria promulgated a nationwide qPCR-based screening programme that aimed to establish the prevalence and distribution of T. equigenitalis in South Africa. This required certification of all South African stallions used for breeding either by natural cover or assisted reproductive techniques. The compliance for certification was based on submission of two sets of genital swabs that both tested negative for T. equigenitalis on qPCR-testing. The process was coordinated by a web-based platform (http://wto the prescribed World Organisation for Health (OIE) method (Terrestrial Manual on Contagious Equine Metritis). All stallions apart from one could be linked to the index property. As of 31st October 2013, two additional T. equigenitalis-positive females have been identified, following a traceback of all identified potentially-exposed mares and their offspring that was instituted in September 2012. An “exposed mare” was defined as a mare that had been bred, either by natural breeding or assisted breeding techniques to the index stallion or any other T. equigenitalis-positive stallion. These mares were distributed across five provinces of South Africa at the time the traceback was initiated. During the nationwide traceback, a subpopulation focus was identified when 24 of the 33 resident stallions at the South African Lipizzaner Centre, Midrand, Gauteng tested positive for T. equigenitalis. Six of these stallions had visited the index property for semen collection over the course of several years prior to the arrival of the index stallion. This suggested the possible albeit undetected presence of T. equigenitalis on these premises prior to the arrival of the first reported index case. We strongly suspected that there may have been undetected CEM incursions into South Africa in the past. The index case in this outbreak may either have introduced a new infection or was infected by a pre-existing source of infection subsequent to his arrival. It is hoped that future strain-typing of the isolates from the positive cases identified during this intervention will further clarify this scenario. The use of qPCR-based screening proved to be a highly specific and sensitive method for detecting T. equigenitalis and helped to define the distribution and prevalence of T. equigenitalis in breeding stallions and exposed mares in South Africa. In addition, this method had significant practical advantages with respect to the associated costs, turn-around times and in-the-field application when compared with bacterial culture. The institution of a web-based platform from which the national screening programme was launched and coordinated proved to be indispensable in managing stakeholder access and information availability. To date, 31st October 2013, a total of 39 horses (36 males and 3 females) have been identified as T. equigenitalis-positive and have all subsequently been successfully treated. © Universityww.cemsa.co.za) As of 31st October 2013, an additional 33 carrier stallions have been identified by this screening programme. Of these stallions, 23 have been confirmed on bacteriology according to the prescribed World Organisation for Health (OIE) method (Terrestrial Manual on Contagious Equine Metritis). All stallions apart from one could be linked to the index property. As of 31st October 2013, two additional T. equigenitalis-positive females have been identified, following a traceback of all identified potentially-exposed mares and their offspring that was instituted in September 2012. An “exposed mare” was defined as a mare that had been bred, either by natural breeding or assisted breeding techniques to the index stallion or any other T. equigenitalis-positive stallion. These mares were distributed across five provinces of South Africa at the time the traceback was initiated. During the nationwide traceback, a subpopulation focus was identified when 24 of the 33 resident stallions at the South African Lipizzaner Centre, Midrand, Gauteng tested positive for T. equigenitalis. Six of these stallions had visited the index property for semen collection over the course of several years prior to the arrival of the index stallion. This suggested the possible albeit undetected presence of T. equigenitalis on these premises prior to the arrival of the first reported index case. We strongly suspected that there may have been undetected CEM incursions into South Africa in the past. The index case in this outbreak may either have introduced a new infection or was infected by a pre-existing source of infection subsequent to his arrival. It is hoped that future strain-typing of the isolates from the positive cases identified during this intervention will further clarify this scenario. The use of qPCR-based screening proved to be a highly specific and sensitive method for detecting T. equigenitalis and helped to define the distribution and prevalence of T. equigenitalis in breeding stallions and exposed mares in South Africa. In addition, this method had significant practical advantages with respect to the associated costs, turn-around times and in-the-field application when compared with bacterial culture. The institution of a web-based platform from which the national screening programme was launched and coordinated proved to be indispensable in managing stakeholder access and information availability. To date, 31st October 2013, a total of 39 horses (36 males and 3 females) have been identified as T. equigenitalis-positive and have all subsequently been successfully treated. / Dissertation (MMedVet)--University of Pretoria, 2013. / gm2014 / Production Animal Studies / unrestricted

Equine arteritis virus (EAV) is the causal agent of equine viral arteritis (EVA), a disease of equids. Following EAV infection, up to 70% of stallions may become carriers and continuously shed the virus in their semen for varying time periods. The long-term carrier stallion has an important role in the transmission and maintenance of EAV in horse populations. Recently, it has been demonstrated a correlation between in vitro susceptibility of CD3+ T lymphocytes to EAV infection and establishment of long-term persistent infection among stallions following natural infections. In this study, we investigated whether stallions with in vitro EAV susceptible CD3+ T lymphocytes are at higher risk of becoming long-term carriers compared to those with the resistant phenotype following experimental infection with the KY84 strain of EAV. Furthermore, we investigated whether there is a significant effect of EAV infection on semen quality during acute phase of the infection. The data suggested that the establishment of the long-term carrier state seems to be associated with the in vitro CD3+ T lymphocyte susceptible phenotypes and that reduced semen quality resulted from the combined effect of fever and scrotal edema observed following EAV infection rather than the direct effect of the virus.

O objetivo deste trabalho foi avaliar as informações relativas á idade aspectos físicos, como condição corporal (CC), peso corporal (PC), peso do testículo esquerdo (PTE) e direito (PTD), volume testicular (VT), largura testicular esquerdo (LAR), comprimento testícular (COMP), altura testicular (ALT), assim como concentração plasmática de testosterona (TES), além da presença de espermatozóides nos túbulos seminíferos (ETS), para analisar possíveis correlações entre estas variáveis em garanhões da raça Crioula. Por outro lado, realizou-se uma avaliação histológica quanto a presença ou ausência de espermatozóides nos túbulos seminíferos em diferentes idades como também os níveis séricos de testosterona. Estas avaliações foram correlacionadas entre si e foi avaliadas as médias das variáveis por grupo de idades que variaram de 1 a 4 anos. Foram utilizados 70 animais de diferentes regiões do Rio Grande do Sul. A CC média no momento da orquiectomia foi de 3,37, enquanto o PC encontrado foi de 322,53+/-63,79 kg. Quanto ao testículo esquerdo com o epidídimo, o PT médio foi 122,83+/-72,88 g, após a remoção do epidídimo houve uma redução no peso para de 87,77+/-59,74g. O VT foi de 57,89+/-31,19 mL. A LAR encontrada 37,19+/-12,40 mm ao passo que o COMP foi de 67,81+-17,34 mm e a ALT foi de 37,29+/-11,50 mm. Em relação ao testículo direito, com a presença do epidídimo, foi verificado o seguinte peso médio:105,52g+-71,51g. Após a remoção do epidídimo, para o PT, encontrou-se 76,21+-64,99g, VT 51,42+-4,11mL, a LAR foi de 34,97+-13,25mm, COMP foi de 63,94+-19,45mm e a ALT 34,50+-12,21mm. A concentração média de TES dosada foi de 98,25 +/- 122,87 ng/ml de plasma. Em 77,14% dos 35 cortes histológicos realizados, foram encontrados espermatozóides na luz dos túbulos seminíferos. / The aim this study was to evaluate age and physical aspects, such body condition (CC), body weight (PC), left testicle weight (PTE), right testicle weight (PTD), testicular volume (VT), testicular width (LAR) testicular length (COMP), testicular height (ALT) and plasma testosterone levels (TES), and the presence of spermatozoa in the seminiferous tubules (ETS) related information, to analyze possible correlations between these variables in stallions from the Crioulo breed. Moreover, the histological evaluation was made for the presence of spermatozoa in the seminiferous tubules in ages different and plasma testosterone levels. These evaluations were correlated and variables means of the age group (age 1 to 4). Seventy animals were used from different regions of Rio Grande do Sul,in age ranging from 375 to 1579 days (average of 777.94 days). The CC average at the time of orchiectomy was 3.37, while the PC found was 322.53+/-63.79 kg. As regards the left testicle with the epididymis, the PTE average was 122.83+/-72.88 g and after the removal of the epididymis there was a reduction to 87.77+/-59.74 g. The VOL was 57,89+/-31,19 mL. The LAR found was 37.19+/-12.40 mm whereas the COMP was 67.81+/-17.34 mm and ALT was 37.29 +/-11.50 mm. In relation to the right testicle, with the presence of the epididymis, was observed the following average: 105.52+/-71.51 g. After the removal of epididymis, for the PTD, it was found 76.21+/-64.99 g, VOL 51,42+/-4,11mL, the LAR was 34.97+/-13.25 mm, COMP was 63, 94+/-19.45 mm and ALT 34.50+/-12.21 mm. The average concentration of TES assayed was 98.25+/-122.87 ng / ml of plasma. In 77.14% of the 35 histological slices done, spermatozoa were found in the lumen of the seminiferous tubules.

O objetivo deste trabalho foi avaliar as informações relativas á idade aspectos físicos, como condição corporal (CC), peso corporal (PC), peso do testículo esquerdo (PTE) e direito (PTD), volume testicular (VT), largura testicular esquerdo (LAR), comprimento testícular (COMP), altura testicular (ALT), assim como concentração plasmática de testosterona (TES), além da presença de espermatozóides nos túbulos seminíferos (ETS), para analisar possíveis correlações entre estas variáveis em garanhões da raça Crioula. Por outro lado, realizou-se uma avaliação histológica quanto a presença ou ausência de espermatozóides nos túbulos seminíferos em diferentes idades como também os níveis séricos de testosterona. Estas avaliações foram correlacionadas entre si e foi avaliadas as médias das variáveis por grupo de idades que variaram de 1 a 4 anos. Foram utilizados 70 animais de diferentes regiões do Rio Grande do Sul. A CC média no momento da orquiectomia foi de 3,37, enquanto o PC encontrado foi de 322,53+/-63,79 kg. Quanto ao testículo esquerdo com o epidídimo, o PT médio foi 122,83+/-72,88 g, após a remoção do epidídimo houve uma redução no peso para de 87,77+/-59,74g. O VT foi de 57,89+/-31,19 mL. A LAR encontrada 37,19+/-12,40 mm ao passo que o COMP foi de 67,81+-17,34 mm e a ALT foi de 37,29+/-11,50 mm. Em relação ao testículo direito, com a presença do epidídimo, foi verificado o seguinte peso médio:105,52g+-71,51g. Após a remoção do epidídimo, para o PT, encontrou-se 76,21+-64,99g, VT 51,42+-4,11mL, a LAR foi de 34,97+-13,25mm, COMP foi de 63,94+-19,45mm e a ALT 34,50+-12,21mm. A concentração média de TES dosada foi de 98,25 +/- 122,87 ng/ml de plasma. Em 77,14% dos 35 cortes histológicos realizados, foram encontrados espermatozóides na luz dos túbulos seminíferos. / The aim this study was to evaluate age and physical aspects, such body condition (CC), body weight (PC), left testicle weight (PTE), right testicle weight (PTD), testicular volume (VT), testicular width (LAR) testicular length (COMP), testicular height (ALT) and plasma testosterone levels (TES), and the presence of spermatozoa in the seminiferous tubules (ETS) related information, to analyze possible correlations between these variables in stallions from the Crioulo breed. Moreover, the histological evaluation was made for the presence of spermatozoa in the seminiferous tubules in ages different and plasma testosterone levels. These evaluations were correlated and variables means of the age group (age 1 to 4). Seventy animals were used from different regions of Rio Grande do Sul,in age ranging from 375 to 1579 days (average of 777.94 days). The CC average at the time of orchiectomy was 3.37, while the PC found was 322.53+/-63.79 kg. As regards the left testicle with the epididymis, the PTE average was 122.83+/-72.88 g and after the removal of the epididymis there was a reduction to 87.77+/-59.74 g. The VOL was 57,89+/-31,19 mL. The LAR found was 37.19+/-12.40 mm whereas the COMP was 67.81+/-17.34 mm and ALT was 37.29 +/-11.50 mm. In relation to the right testicle, with the presence of the epididymis, was observed the following average: 105.52+/-71.51 g. After the removal of epididymis, for the PTD, it was found 76.21+/-64.99 g, VOL 51,42+/-4,11mL, the LAR was 34.97+/-13.25 mm, COMP was 63, 94+/-19.45 mm and ALT 34.50+/-12.21 mm. The average concentration of TES assayed was 98.25+/-122.87 ng / ml of plasma. In 77.14% of the 35 histological slices done, spermatozoa were found in the lumen of the seminiferous tubules.

O objetivo deste trabalho foi avaliar as informações relativas á idade aspectos físicos, como condição corporal (CC), peso corporal (PC), peso do testículo esquerdo (PTE) e direito (PTD), volume testicular (VT), largura testicular esquerdo (LAR), comprimento testícular (COMP), altura testicular (ALT), assim como concentração plasmática de testosterona (TES), além da presença de espermatozóides nos túbulos seminíferos (ETS), para analisar possíveis correlações entre estas variáveis em garanhões da raça Crioula. Por outro lado, realizou-se uma avaliação histológica quanto a presença ou ausência de espermatozóides nos túbulos seminíferos em diferentes idades como também os níveis séricos de testosterona. Estas avaliações foram correlacionadas entre si e foi avaliadas as médias das variáveis por grupo de idades que variaram de 1 a 4 anos. Foram utilizados 70 animais de diferentes regiões do Rio Grande do Sul. A CC média no momento da orquiectomia foi de 3,37, enquanto o PC encontrado foi de 322,53+/-63,79 kg. Quanto ao testículo esquerdo com o epidídimo, o PT médio foi 122,83+/-72,88 g, após a remoção do epidídimo houve uma redução no peso para de 87,77+/-59,74g. O VT foi de 57,89+/-31,19 mL. A LAR encontrada 37,19+/-12,40 mm ao passo que o COMP foi de 67,81+-17,34 mm e a ALT foi de 37,29+/-11,50 mm. Em relação ao testículo direito, com a presença do epidídimo, foi verificado o seguinte peso médio:105,52g+-71,51g. Após a remoção do epidídimo, para o PT, encontrou-se 76,21+-64,99g, VT 51,42+-4,11mL, a LAR foi de 34,97+-13,25mm, COMP foi de 63,94+-19,45mm e a ALT 34,50+-12,21mm. A concentração média de TES dosada foi de 98,25 +/- 122,87 ng/ml de plasma. Em 77,14% dos 35 cortes histológicos realizados, foram encontrados espermatozóides na luz dos túbulos seminíferos. / The aim this study was to evaluate age and physical aspects, such body condition (CC), body weight (PC), left testicle weight (PTE), right testicle weight (PTD), testicular volume (VT), testicular width (LAR) testicular length (COMP), testicular height (ALT) and plasma testosterone levels (TES), and the presence of spermatozoa in the seminiferous tubules (ETS) related information, to analyze possible correlations between these variables in stallions from the Crioulo breed. Moreover, the histological evaluation was made for the presence of spermatozoa in the seminiferous tubules in ages different and plasma testosterone levels. These evaluations were correlated and variables means of the age group (age 1 to 4). Seventy animals were used from different regions of Rio Grande do Sul,in age ranging from 375 to 1579 days (average of 777.94 days). The CC average at the time of orchiectomy was 3.37, while the PC found was 322.53+/-63.79 kg. As regards the left testicle with the epididymis, the PTE average was 122.83+/-72.88 g and after the removal of the epididymis there was a reduction to 87.77+/-59.74 g. The VOL was 57,89+/-31,19 mL. The LAR found was 37.19+/-12.40 mm whereas the COMP was 67.81+/-17.34 mm and ALT was 37.29 +/-11.50 mm. In relation to the right testicle, with the presence of the epididymis, was observed the following average: 105.52+/-71.51 g. After the removal of epididymis, for the PTD, it was found 76.21+/-64.99 g, VOL 51,42+/-4,11mL, the LAR was 34.97+/-13.25 mm, COMP was 63, 94+/-19.45 mm and ALT 34.50+/-12.21 mm. The average concentration of TES assayed was 98.25+/-122.87 ng / ml of plasma. In 77.14% of the 35 histological slices done, spermatozoa were found in the lumen of the seminiferous tubules.