The aim of this study was to evaluate temperature data collected from Thoroughbred foals between birth and shortly after weaning. It provides a valuable survey with epidemiological conclusions providing insight into the temperature trends and pyretic occurrences of Thoroughbred foals during this age period. Temperature data were collected using telemetry from temperature sensitive microchips implanted into newborn foals. The system of inputting and storing temperature data was completely electronic and this study evaluated this system. It was found that this system was stable and allowed the evaluation of large amounts of frequently acquired data with little human intervention. The data obtained resulted in the valuable evaluation of age associated body temperature trends within the foals as well as providing an indication of the extent and epidemiology of pyrexia within the study cohort. The system of evaluating temperatures based both on the individual day value as well as on each individual foals prior series of temperatures shows that the use of these two criteria can be utilised simultaneously. The study provides basic information which future researchers using similar systems can use to objectively set criteria for pyrexia. An outbreak of equine encephalosis also occurred during the study period and this provided much needed prospective epidemiological information for such an outbreak, something which has not previously been documented. Copyright / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2009. / Production Animal Studies / unrestricted

A naturally occurring disease involving hyperplasia of the thyroid gland and a consistent pattern of musculoskeletal deformities of newborn foals in western Canada was first described in 1981. This disease was an important cause of foal mortality and, therefore, reproductive loss throughout western Canada during the 1990s and has since been recognized in western Ontario and the northwestern United States. A series of investigations were conducted to describe, characterize, and attempt to determine the pathogenesis and cause of this syndrome. Affected foals were typically born after a long gestation (x = 360 days, range = 340 to 400 days), were diagnosed as hypothyroid based on a poor response to the administration of thyroid-stimulating hormone, and had various musculoskeletal lesions of which mandibular prognathism, flexural deformities and rupture of tendons of the limbs, and incomplete ossification of the carpal and tarsal bones were present most commonly. In spite of the normal to long gestation, foals had signs of immaturity, were usually weak and unable to stand, became septic, and died or were euthanatised. Similar histories, clinical findings, and lesions were present in surgically created hypothyroid foals that were thyroidectomized in utero at about 210 days gestation. These findings supported the conclusion that foals which naturally developed these lesions were also hypothyroid in utero and that all the lesions present in affected foals were the result of the hypothyroidism and not of an underlying concurrent disease process. A case-control study was conducted to identify risk factors for naturally occurring congenital hypothyroidism. Information from congenitally hypothyroid foals concerning foal and dam signalment, farm environment, and dam management was compared with that from normal foals. Pregnant mares fed greenfeed, not supplemented with mineral, that left their "home farm" during gestation, or grazed irrigated pasture, had a 13.1 (<i>P</i>=0.0068), 5.6 (<i>P</i>=0.0472), 4.3 (<i>P</i>=0.0076) and approximately 15.3 (<i>P</i>=0.0245) times greater odds, respectively, of producing a congenitally hypothyroid foal than mares not exposed to these factors. Greenfeed often contains high levels of nitrate (NO₃^-) which is known to impair thyroid gland function. In light of this, forage samples from participating farms were analysed for nitrate levels. The odds of one or more congenitally hypothyroid foal being born on a farm feeding forage with at least a trace of nitrate was 8.0 times greater (<i>P</i>=0.0873) than the odds of the disease occurring a farm that fed forage free of nitrate. Further, the odds of a mare producing an affected foal when fed forage containing at least a trace of nitrate was 5.9 times greater (<i>P</i>=0.0007) than a mare fed nitrate-free forage.This study suggests that congenital hypothyroidism in foals may result from diets containing nitrate or low in iodine being fed to pregnant mares. These results need to be confirmed through further field investigations and controlled experiments. However, if they are accurate, there is cause for concern that other livestock raised in areas where congenitally hypothyroid foals occur may be exposed to the same dietary risk factors and may suffer similar disease.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2001. / Härtill 5 uppsatser.

Orientador: Maria Lucia Gomes Lourenço / Resumo: Atualmente, observamos uma maior necessidade de uma assistência adequada tanto pré-natal, quanto neonatal com o intuito de se reduzir a mortalidade de recém-nascidos, principalmente de animais com elevado valor genético e zootécnico. O exame eletrocardiográfico pode se revelar como ferramenta importante em neonatologia equina, visto que permite a determinação da frequência cardíaca, do ritmo cardíaco, distúrbios de condução e obtenção de índices de variabilidade da frequência cardíaca. Este trabalho visou retratar o comportamento dos parâmetros eletrocardiográficos em éguas prenhes, fetos e potros neonatos, com o intuito de determinar se a frequência cardíaca (FC) e os índices de variabilidade da frequência cardíaca (VFC) materna e fetal são indicativos da proximidade do parto; determinar viabilidade fetal e neonatal, e descrever a evolução do desenvolvimento do sistema nervoso autônomo durante este período, bem como detectar as particularidades na dinâmica eletrocardiográfica durante o período neonatal nos equinos da raça Paint Horse. Foram avaliados 20 éguas, 20 fetos e 20 potros cujos exames eletrocardiográficos maternos e fetais foram realizados entre 15 e sete dias pré-parto. Quanto ao eletrocardiograma neonatal, os momentos a serem avaliados foram: ao nascimento, quatro, oito, 12, 16, 20, 24, 36 e 48 horas pós parto e posteriormente uma vez por semana até os 35 dias de idade. Os resultados obtidos da VFC fetal e neonatal do presente estudo, quando comparados aos materno... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Currently, we observe an increased need for adequate assistance both prenatal, neonatal as aiming to reduce mortality of newborns, mainly animals with high genetic and livestock value. The electrocardiogram can represent an important tool in equine neonatology, since this test allows the determination of heart rate, cardiac rhythm, disturbances of conduction and obtaining indexes of heart rate variability. This study aimed to represent the behavior of electrocardiographic parameters in mares, fetuses and newborn foals, in order to determine whether the heart rate (HR) and indexes of heart rate variability (HRV) of the mare and the fetuses are indicative of birth proximity; to determine the fetal and neonatal viability, to describe the evolution of the development of the autonomic nervous system during this period, and to detect the particulars in the electrocardiographic dynamic during the neonatal period in foals of Paint Horse breed. There were 20 mares, 20 fetuses and 20 newborn foals, whose maternal and fetal electrocardiographic examinations were performed at, approximately, 15 and 07 days prepartum. The neonatal electrocardiogram occurred: at birth, four, eight, 12, 16, 20, 24, 36 and 48 hours after delivery and thereafter once per week until 35 days of age. The results of fetal and neonatal HRV of the present study, when compared to maternal indicated the parasympathetic dominance during fetal and neonatal sympathetic dominance during to the third and / or fourth weeks... (Complete abstract click electronic access below) / Mestre

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study evaluated molecular characteristic of Rhodococcus equi isolates obtained from horses and standardized by PCR multiplex assay, which amplifies the vap gene family (vapA, B, C, D, E, F, G e H). One hundred eighty Rhodococcus equi isolates from different sources: healthy horse s feces (112), soil (12), stalls (23) and clinical isolates (33) of horsebreeding farms, were studied. The technique was standardized and confirmed by sequencing of amplified vap gene family controls. Thirty-two (17.8%) R. equi isolates evaluated were positive for vapA gene and carried at least three another vap genes associated. All 147 isolates from equine feces, stalls and soil from horse-breeding farms did not demonstrate any virulence-associated proteins genes. Thirty-two (97.0%) out of 33 clinical equines isolates were positive to multiplex PCR assay for vap gene family and demonstrated six molecular profile, 100% with vapA, vapD and vapG genes, 86.6% vapF, 76,6% vapH, 43.3% vapC, 36.6% vapE and none vapB. The most frequent molecular profile was vap A, D, F, G and H present in 37.5% of strains. Morever, there was no molecular epidemiological pattern for R. equi isolates from each horse-breeding farm studied. Thus this technique allows the identification of eight vap genes family (vapA, B, C, D, E, F, G e H), it is a practical an efficient method of conducting clinical and epidemiological studies on R. equi isolates. / O presente estudo tem por objetivo a caracterização molecular de isolados de Rhodococcus equi de eqüinos pela padronização de uma técnica de PCR multiplex para detecção dos genes da família vap (vapA, B, C, D, E, F, G e H). Foram analisadas 180 amostras de Rhodococcus equi de diferentes origens: fezes (112), solo (12) instalações (23) e isolados clínicos (33). A técnica foi padronizada e confirmada pelo sequenciamento da cepa padrão de R. equi (ATCC 33701), e de uma amostra de paciente humano contendo o gene vapB. Trinta e dois (17,8%) foram positivos para vapA e carregavam no mínimo 4 genes vap associados. Os 147 isolados oriundos de fezes, instalações e sola não apresentavam genes vap. Trinta e dois (97.0%) dos isolados clinicos foram positivos na PCR multiplex e demonstraram seis padrões moleculares, 100% com vapA, vapD and vapG, 86.6% vapF, 76,6% vapH, 43.3% vapC, 36.6% vapE e nenhum com vapB. O perfil molecular mais freqüente foi vap A, D, F, G eH presente em 37.5% das cepas. foram obtidos, sendo que os genes vapA, vapD e vapG estavam presentes em todas as amostras. Não foi obtido nenhum padrão molecular para cada propriedade estudada. Esta nova técnica constitui-se um método prático e eficaz para condução de estudos clínicos e epidemiológicos, bem como, por relevar os aspectos moleculares da infecção.

Made available in DSpace on 2014-08-20T14:37:55Z (GMT). No. of bitstreams: 1 dissertacao_leandro_ribas.pdf: 533423 bytes, checksum: 051e6999778a1a91a3b217f25f75e25b (MD5) Previous issue date: 2008-03-10 / The present study has the objective to evaluate the epidemiologic factors related to respiratory diseases in thoroughbred foals placed in four stud farms around the city of Bagé/RS region, Brazil. Apart from the collection of data linked to breeding management practices, the evaluations consisted of the diary clinical control and complementary examinations for diagnosis using secretions collected from the respiratory tract of the foals affected with respiratory diseases. Among the 349 monitored foals until their 180 days of life, the incidence of 9,5% (33) of respiratory cases with 0,57% (2) of mortality was recorded. The concentration of cases was higher in months of summer, the 120 and 180 days old foals were more susceptible. The occurrence of the diseases was influenced by the breeding system and management practices that increased the environmental contamination potential, and also by the contact among the foals. No clinic case was related to the equine influenza virus (EIV) and to the equine herpesvirus (EHV) pathogens. Among the isolated pathogens, the highest frequency was for Streptococcus equi (57%), followed by Rhodococcus equi (17%) and this one was responsible for 50% of lethality. The obtained results suggest that connected factors to the management in the breeding of thoroughbred equine are going to contribute decisively for the manifestation of the respiratory disease and alert for the high morbidity caused by the equine adenitis and the high lethality related to Rhodococcus equi pathogens. / O presente estudo teve por objetivo avaliar fatores epidemiológicos associados com doenças respiratórias em potros Puro Sangue Inglês (PSI) alojados em 4 propriedades na região da cidade de Bagé-RS, Brasil. Além da coleta de dados ligados ao manejo de criação, as avaliações consistiram no monitoramento clínico diário e exames complementares de diagnóstico a partir de secreções colhidas do trato respiratório de potros com enfermidade respiratória. Entre os 349 potros monitorados até os 180 dias de vida, pôde-se registrar a incidência de 9,5% (33) de casos respiratórios, com mortalidade de 0,57% (2). A concentração de casos foi mais elevada nos meses de verão e potros com idade entre 120 e 180 dias foram mais suscetíveis. A ocorrência de doenças foi influenciada pelo sistema de criação e práticas de manejo que aumentaram o potencial de contaminação do ambiente e o contato entre potros. Nenhum caso clínico foi relacionado ao vírus da influenza (EIV) e ao herpesvírus eqüino (EHV). Entre os isolados, a maior freqüência foi de Streptococcus equi (57%), seguido do Rhodococcus equi (17%), este responsável pela letalidade de 50%. Os resultados sugerem que fatores ligados ao manejo na criação de eqüinos PSI parecem contribuir decisivamente para a manifestação da doença respiratória e alertam para a elevada morbidade causada pela adenite eqüina e a alta letalidade associada à rodococose entre potros jovens (>180 dias).

The project was undertaken to monitor a group of 30 foals on a farm both clinically and microbiologically from birth until one year of age, to determine the aetiology of upper respiratory tract infections and to establish immune profiles of some of the known respiratory viral pathogens. One to two months prior to the birth of their foals, blood for serology was collected from the mares. The same specimens were collected from the foals just after birth, prior to suckling and a day after suckling. Thereafter the foals were examined monthly for the presence of respiratory disease and specimens taken. The following specimens were collected from each foal: three nasopharyngeal swabs, (one for virus isolation, one for bacteria and fungus isolation, and one for mycoplasma isolation) and blood that was allowed to clot. Blood was collected in heparin from sick foals with elevated rectal temperatures. Virus isolation was done on roller tube cultures of equine embryonic lung (EEL), Vero cells and rabbit kidney 13 (RK13) cells. The bacteria (including mycoplasmas) and fungi were cultured from the swabs and identified using a variety of traditional methods. The serum neutralization test (SNT) was used to detect antibodies to equid herpesvirus 1 (EHV-1), equid herpesvirus 4 (EHV-4), equine rhinovirus 1 (ERV-1), equine rhinovirus 2 (ERV-2) and equine adenovirus 1 (EAdV-1). The complement fixation test (CFT) was used to detect antibodies to EHV-1 and EHV-4 and the haemagglutination inhibition test (HIT) antibodies to equine influenzavirus (EIV). Only EHV-4 was cultured from the nasopharyngeal swabs of nine foals when they were 5 to 6 months of age and from one foal two months later. A wide variety of bacteria and fungi were cultured and it was established that coagulase-negative staphylococci, viridans streptococci, Moraxella spp. and Flavobacterium spp. predominated in most of the samples. Several potential bacterial pathogens were isolated but the most common were Streptococcus equi subsp. zooepidemicus, Actinobacillus equuland Staphylococcus aureus. Colostrum-derived antibodies were detected for all the viruses in all but two of the foals. It was found that the foals had similar or slightly higher titres than their mothers. The levels declined in direct proportion to what they initially were and were depleted by the time the foals were 2 to 7 months of age. Antibodies to natural infection was detected to EHV-4, ERV-2 and EAdV-1. A rise in antibody titres occurred when the foals were 5 to 6 months of age, two months later and when they were one year of age. Antibodies resulting from immunization was detected to EHV-1, EHV-4 and EIV. It was established that the most important virus causing upper respiratory tract disease of the foals from 5 to 12 months of age was EHV-1 with EAdV-1 playing a minor role. These viruses caused repeated bouts of infection with a two to five months interval. Streptococcus equi subsp. zooepidemicus was considered to be the most important secondary pathogen. Prior to this period most of the foals were healthy with only a few suffering from upper respiratory disease. The aetiology was not determined in these cases, but based on the bacteriology results, it was suspected that some of them were suffering from bacterial infections. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2005. / Veterinary Tropical Diseases / unrestricted

Le potentiel acoustique évoqué (PAE) est influencé par l’âge dans de nombreuses espèces. Chez l’homme, l’augmentation de la fréquence de stimulation améliore la détection des anomalies du tronc cérébral. Son utilisation chez le poulain demeure anecdotique. Les buts de cette étude étaient: 1) de déterminer les valeurs de référence du PAE pour 3 différents protocoles de stimulation (11.33 Hz/70 dBNHL; 11.33 Hz/90 dBNHL; 90 Hz/70 dBNHL); 2) d’évaluer les effets de l’âge et de la fréquence de répétition de la stimulation acoustique sur les tracés du PAE chez le poulain de moins de 6 mois; 3) de comparer les données obtenues chez les poulains normaux à celles recueillies chez des poulains présentant des troubles neurologiques. Trente-neuf poulains normaux et 16 poulains avec des déficits neurologiques ont été inclus dans l’étude. Aucun effet de l’âge n’a été mis en évidence (p> 0,005). Aucune différence significative n’a été mise en évidence lorsque les latences absolues et relatives des poulains neurologiques ont été comparées à celles des poulains normaux (p>0,005). L’augmentation de la fréquence de stimulation acoustique n’a pas amélioré la détection d’anomalies sur les tracés de PAE chez les poulains neurologiques. Bien que toutes leurs valeurs de latences absolues et relatives soient demeurées à l’intérieur des valeurs de référence, 78,6% des poulains avec un déficit neurologique présentaient une asymétrie entre les tracés des deux oreilles. Cela démontre une différence de conduction de l’influx nerveux entre le côté droit et le côté gauche du tronc cérébral chez ces sujets. En conclusion, nous présentons ici les valeurs de référence du PAE chez le poulain de moins de 6 mois pour 3 protocoles de stimulation différents. D’autres études seraient nécessaire afin de déterminer si l’utilisation d’une fréquence de stimulation acoustique plus élevée est utile dans la détection d’anomalies du PAE chez les poulains souffrant de troubles neurologiques. La majorité des poulains avec des déficits neurologiques ont présenté des anomalies du PAE ce qui valide son utilisation pour le diagnostic de troubles neurologiques chez le poulain de moins de 6 mois. / Age and rate of acoustic stimulation are reported to affect peak latencies in brainstem auditory evoked responses (BAER) in different species. In foals, its use remains quite anecdotic but, as in humans and dogs, could be useful in the early diagnosis of central nervous system (CNS) disorders. The goals of this study were to 1) establish the reference values for BAER in foals using 3 different stimulation protocols (11.33 Hz/70 dBNHL; 11.33 Hz/90 dBNHL; 90 Hz/70 dBNHL), 2) evaluate the effects of age and rate of stimulation on BAER traces in foals up to 6 months old, and 3) compare these data with BAER obtained from foals with CNS disorders. Thirty-nine neurologically normal foals and 16 foals with neurological deficits were included in this study. No effects of age were observed in normal foals (p> 0.005). No significant differences were observed for latencies and interpeak latencies (IPL) when neurological foals were compared to normal foals (p> 0.05). Increasing the stimulation rate did not improve detection of CNS disorders. All neurologically abnormal foals had latencies and IPL within reference values. However, 78.6% of them had an asymmetry in their traces, reflecting a difference in conduction time between the left and right size of the brainstem. In conclusion, we provide reference values of BAER for foals up to 6 months using 3 different protocols. Further investigations are needed to conclude on the use of an increased rate of acoustic stimulation in foals. Most importantly, most foals with neurological deficits had also an abnormal BAER. This proves BAER is useful is the early diagnosis of neurological disorders in foals

Le potentiel acoustique évoqué (PAE) est influencé par l’âge dans de nombreuses espèces. Chez l’homme, l’augmentation de la fréquence de stimulation améliore la détection des anomalies du tronc cérébral. Son utilisation chez le poulain demeure anecdotique. Les buts de cette étude étaient: 1) de déterminer les valeurs de référence du PAE pour 3 différents protocoles de stimulation (11.33 Hz/70 dBNHL; 11.33 Hz/90 dBNHL; 90 Hz/70 dBNHL); 2) d’évaluer les effets de l’âge et de la fréquence de répétition de la stimulation acoustique sur les tracés du PAE chez le poulain de moins de 6 mois; 3) de comparer les données obtenues chez les poulains normaux à celles recueillies chez des poulains présentant des troubles neurologiques. Trente-neuf poulains normaux et 16 poulains avec des déficits neurologiques ont été inclus dans l’étude. Aucun effet de l’âge n’a été mis en évidence (p> 0,005). Aucune différence significative n’a été mise en évidence lorsque les latences absolues et relatives des poulains neurologiques ont été comparées à celles des poulains normaux (p>0,005). L’augmentation de la fréquence de stimulation acoustique n’a pas amélioré la détection d’anomalies sur les tracés de PAE chez les poulains neurologiques. Bien que toutes leurs valeurs de latences absolues et relatives soient demeurées à l’intérieur des valeurs de référence, 78,6% des poulains avec un déficit neurologique présentaient une asymétrie entre les tracés des deux oreilles. Cela démontre une différence de conduction de l’influx nerveux entre le côté droit et le côté gauche du tronc cérébral chez ces sujets. En conclusion, nous présentons ici les valeurs de référence du PAE chez le poulain de moins de 6 mois pour 3 protocoles de stimulation différents. D’autres études seraient nécessaire afin de déterminer si l’utilisation d’une fréquence de stimulation acoustique plus élevée est utile dans la détection d’anomalies du PAE chez les poulains souffrant de troubles neurologiques. La majorité des poulains avec des déficits neurologiques ont présenté des anomalies du PAE ce qui valide son utilisation pour le diagnostic de troubles neurologiques chez le poulain de moins de 6 mois. / Age and rate of acoustic stimulation are reported to affect peak latencies in brainstem auditory evoked responses (BAER) in different species. In foals, its use remains quite anecdotic but, as in humans and dogs, could be useful in the early diagnosis of central nervous system (CNS) disorders. The goals of this study were to 1) establish the reference values for BAER in foals using 3 different stimulation protocols (11.33 Hz/70 dBNHL; 11.33 Hz/90 dBNHL; 90 Hz/70 dBNHL), 2) evaluate the effects of age and rate of stimulation on BAER traces in foals up to 6 months old, and 3) compare these data with BAER obtained from foals with CNS disorders. Thirty-nine neurologically normal foals and 16 foals with neurological deficits were included in this study. No effects of age were observed in normal foals (p> 0.005). No significant differences were observed for latencies and interpeak latencies (IPL) when neurological foals were compared to normal foals (p> 0.05). Increasing the stimulation rate did not improve detection of CNS disorders. All neurologically abnormal foals had latencies and IPL within reference values. However, 78.6% of them had an asymmetry in their traces, reflecting a difference in conduction time between the left and right size of the brainstem. In conclusion, we provide reference values of BAER for foals up to 6 months using 3 different protocols. Further investigations are needed to conclude on the use of an increased rate of acoustic stimulation in foals. Most importantly, most foals with neurological deficits had also an abnormal BAER. This proves BAER is useful is the early diagnosis of neurological disorders in foals