No description available.

A determinação da morfologia e dimensões da traqueia são imprescindíveis para o diagnóstico de hipoplasia e definição do tamanho de stent e escolha de sonda endotraqueal apropriada. O buldogue inglês é o principal representante da hipoplasia traqueal e também da síndrome obstrutiva respiratória do cão braquicefálico (SORB). Assim, o conhecimento dos parâmetros da normalidade nesta raça é essencial para o auxílio diagnóstico destas afecções. O exame radiográfico tem sido a modalidade de eleição, entretanto, com a facilidade de acesso à tomografia computadorizada (TC) e melhor resolução espacial, a padronização dos parâmetros da TC se tornou igualmente importante. A presente pesquisa teve como objetivos revisar a literatura quanto as principais modalidades de diagnóstico por imagem para avaliação da traqueia, aplicar de métodos de mensuração traqueal já descritos por meio do exame radiográfico, sugerir o estudo da avaliação morfológica e morfométrica da traqueia e da faringe em cães buldogue inglês por meio da (TC), comparar os achados obtidos pela TC com os radiográficos, e correlacioná-los com as manifestações clínicas da SORB. Incluíram-se cães da raça buldogue inglês com graus I e II da SORB, os quais foram submetidos ao exame de TC (n=31) e de radiografia computadorizada (n=37) da faringe e traqueia. Ao exame radiográfico, avaliouse a traqueia pelo uso de métodos morfométricos previamente estabelecidos pela literatura, e pela análise morfológica. Pela TC e pelo exame radiográfico, avaliou-se o diâmetro e área transversal da traqueia, assim como sua morfologia. Ainda, avaliou-se pela TC e pelo exame radiográfico, o diâmetro e área transversal da nasofaringe e a espessura e comprimento do palato mole. Por meio do método de Bland-Altman, analisou-se a comparação estatística entre as modalidades de imagem, e por meio do coeficiente de correlação de Spearman, testou-se a correlação entre os achados morfométricos com as manifestações clínicas da SORB. Para tanto, esta pesquisa foi dividida em quatro capítulos, e a metodologia detalhada, resultados, discussões e conclusões estão apresentados individualmente em cada capítulo / Determination of the morphology and dimensions of the trachea are essential for the hypoplasia diagnosis, for stent size definition and appropriate endotracheal tube selection. The English Bulldog is the most affected breed with the tracheal hypoplasia and also brachycephalic obstructive airway syndrome (BOAS). Thus, knowledge of the normal range in this breed is essential to aid diagnosis of these diseases. Radiographic analysis has been the method of choice, however, the increased access to computed tomography (CT) and better spatial resolution, the standardization of CT parameters became equally important. This study aimed to review the literature of the main modalities of diagnostic imaging for evaluation of the trachea, apply tracheal measurement methods already described by radiographic examination, suggest the study of morphological and morphometric evaluation of the trachea and pharynx in English Bulldog by (CT), compare the CT and radiographic results, and correlate them with the clinical manifestations of BOAS. English Bulldog classified as BOAS grade I and II were included and underwent to CT scan (n = 31) and computed radiography (n = 37) of the pharynx and trachea. Radiographic examination evaluated the trachea with morphometric methods previously established in the literature, and with morphological analysis. Diameter and cross-sectional area of the trachea, as well as their morphology was evaluated by CT and the radiograph. Also, the diameter and crosssectional area of the nasopharynx, as well as the thickness and length of the soft palate was evaluated by CT and radiographic examination. Bland-Altman method, was used to analyzed the statistical comparison between imaging modalities, and the Spearman correlation coefficient was used to test morphometric findings with the clinical signs of SORB. Therefore, this study was divided into four chapters, and detailed methodology, results, discussion and conclusions are presented individually in each chapter

O gênero Noctilio pertence à superfamília Noctilionoidea, família Noctilionidae, e inclui atualmente duas espécies de distribuição Neotropical, N. leporinus e N. albiventris. Estas ocorrem em simpatria nas áreas de planície desde a costa pacífica do México até o Norte da Argentina e Uruguai. N. leporinus possui características morfológicas externas e funcionais que o tornam adaptado à piscivoria, apesar de trabalhos citarem para sua alimentação um consumo equivalente de insetos, crustáceos e aracnídeos. N. albiventris possui hábito insetívoro, apresentando características morfológicas externas que se assemelham muito a N. leporinus, sendo apenas de menor tamanho. As duas espécies apresentam variação morfológica ao longo de sua distribuição geográfica, com a descrição de subespécies para ambas. Dados moleculares foram utilizados recentemente para investigar as relações intragenéricas em Noctilio, indicando uma origem recente para N. leporinus e a parafilia de N. albiventris. O presente trabalho teve como objetivo a caracterização genética intraespecífica e a determinação do padrão filogeográfico das espécies do gênero Noctilio, verificando a possibilidade de existência de mais que duas linhagens evolutivas para o táxon. A amostragem incluiu 63 indivíduos de N. leporinus distribuídos por 35 localidades, e 43 indivíduos de N. albiventris de 19 localidades distintas, tendo sido utilizados como marcadores moleculares o gene mitocondrial citocromo b e a região controle do DNAmit. Os resultados corroboraram a parafilia descrita para N. albiventris, além de evidenciarem níveis de divergência filogenética mais significativos do que o alcançado pelo estudo anterior. Foram encontrados em N. albiventris três filogrupos com alto suporte, igualmente distantes do filogrupo de N. leporinus, as quais apresentam uma correlação geográfica com as subespécies propostas. Os testes de desvio da neutralidade em N. leporinus foram significativos, indicando uma rápida expansão populacional após o surgimento da espécie. Estimativas para o cálculo do ACMR das linhagens evolutivas remetem ao período pleistocênico, tanto para o surgimento de N. leporinus como para os três clados encontrados em N. albiventris. A divergência observada entre estas linhagens variou entre 4,3 e 6,1%. O presente estudo permitiu a confirmação do surgimento recente da espécie N. leporinus a partir de uma linhagem de N. albiventris. A hipótese proposta para a origem da linhagem piscívora do gênero foi a colonização das pequenas Antilhas por uma população de N. albiventris durante os ciclos glaciais do Pleistoceno. Ali a população teria se diferenciado, originando N. leporinus, e posteriormente sofrido uma rápida expansão populacional devido à ocupação de um nicho inexplorado por morcegos neotropicais. / The genus Noctilio belongs to the Superfamily Noctilionoidea, Family Noctilionidae, and currently it includes two species with Neotropical distribution, N. leporinus and N. albiventris. Both species occurs simpatrically in lowland areas from western and eastern Mexico, southward to northern Argentina and Uruguay. N. leporinus have functional and external morphologic characteristics that enables it to piscivory, although many works describe an equivalent consume of arachnids, insects and crustaceans in its diet. N. albiventris is insectivore and resembles N. leporinus in most external and cranial features, but is a smaller species. Both species show morphological variation along their geographic range, congruent with the subspecies distribution. A recent study on molecular phylogeny suggested a recent origin for N. leporinus and to the paraphyly of N. albiventris. The main purpose of this work was the intraspecific genetic characterization and the description of phylogeographic patterns of both species of genus Noctilio, in attempt to investigate how many evolutionary lineages are included in the taxon. Sampling included 63 individuals of N. leporinus from 35 distinct localities and 43 individuals of N. albiventris from 19 localities. The mitochondrial gene cytocrome b and the control region from mtDNA were used as molecular markers. The results corroborate the paraphyly described for N. albiventris, and reveals more significant levels of phylogenetic divergence than previously observed. Three highly supported phylogroups were found within N. albiventris, all of them presenting similar phylogenetic distances to the lineage of N. leporinus. These phylogroups showed geographic structure congruent with the N. albiventris subspecies. The tests against neutrality hypothesis in N. leporinus were significant, suggesting a rapid population growth after the origin of the species. Estimates of the MRCA of the evolutionary lineages dates to the Pleistocene, for both the origin of N. leporinus and all three clades found for N. albiventris. Observed divergence between lineages varied from 4.3 to 6.1%. This study corroborates the recent origin of N. leporinus and its closest phylogenetic relationship with a N. albiventris lineage. The hypothesis for the piscivory in the genus Noctilio was the colonization of the Lesser Antilles by a population of N. albiventris during glacial cycles in the Pleistocene. This population may have differentiated, giving rise to N. leporinus, and then getting through a rapid expansion due to a trophic niche previously unexplored by any neotropical bat lineage.

O gênero Noctilio pertence à superfamília Noctilionoidea, família Noctilionidae, e inclui atualmente duas espécies de distribuição Neotropical, N. leporinus e N. albiventris. Estas ocorrem em simpatria nas áreas de planície desde a costa pacífica do México até o Norte da Argentina e Uruguai. N. leporinus possui características morfológicas externas e funcionais que o tornam adaptado à piscivoria, apesar de trabalhos citarem para sua alimentação um consumo equivalente de insetos, crustáceos e aracnídeos. N. albiventris possui hábito insetívoro, apresentando características morfológicas externas que se assemelham muito a N. leporinus, sendo apenas de menor tamanho. As duas espécies apresentam variação morfológica ao longo de sua distribuição geográfica, com a descrição de subespécies para ambas. Dados moleculares foram utilizados recentemente para investigar as relações intragenéricas em Noctilio, indicando uma origem recente para N. leporinus e a parafilia de N. albiventris. O presente trabalho teve como objetivo a caracterização genética intraespecífica e a determinação do padrão filogeográfico das espécies do gênero Noctilio, verificando a possibilidade de existência de mais que duas linhagens evolutivas para o táxon. A amostragem incluiu 63 indivíduos de N. leporinus distribuídos por 35 localidades, e 43 indivíduos de N. albiventris de 19 localidades distintas, tendo sido utilizados como marcadores moleculares o gene mitocondrial citocromo b e a região controle do DNAmit. Os resultados corroboraram a parafilia descrita para N. albiventris, além de evidenciarem níveis de divergência filogenética mais significativos do que o alcançado pelo estudo anterior. Foram encontrados em N. albiventris três filogrupos com alto suporte, igualmente distantes do filogrupo de N. leporinus, as quais apresentam uma correlação geográfica com as subespécies propostas. Os testes de desvio da neutralidade em N. leporinus foram significativos, indicando uma rápida expansão populacional após o surgimento da espécie. Estimativas para o cálculo do ACMR das linhagens evolutivas remetem ao período pleistocênico, tanto para o surgimento de N. leporinus como para os três clados encontrados em N. albiventris. A divergência observada entre estas linhagens variou entre 4,3 e 6,1%. O presente estudo permitiu a confirmação do surgimento recente da espécie N. leporinus a partir de uma linhagem de N. albiventris. A hipótese proposta para a origem da linhagem piscívora do gênero foi a colonização das pequenas Antilhas por uma população de N. albiventris durante os ciclos glaciais do Pleistoceno. Ali a população teria se diferenciado, originando N. leporinus, e posteriormente sofrido uma rápida expansão populacional devido à ocupação de um nicho inexplorado por morcegos neotropicais. / The genus Noctilio belongs to the Superfamily Noctilionoidea, Family Noctilionidae, and currently it includes two species with Neotropical distribution, N. leporinus and N. albiventris. Both species occurs simpatrically in lowland areas from western and eastern Mexico, southward to northern Argentina and Uruguay. N. leporinus have functional and external morphologic characteristics that enables it to piscivory, although many works describe an equivalent consume of arachnids, insects and crustaceans in its diet. N. albiventris is insectivore and resembles N. leporinus in most external and cranial features, but is a smaller species. Both species show morphological variation along their geographic range, congruent with the subspecies distribution. A recent study on molecular phylogeny suggested a recent origin for N. leporinus and to the paraphyly of N. albiventris. The main purpose of this work was the intraspecific genetic characterization and the description of phylogeographic patterns of both species of genus Noctilio, in attempt to investigate how many evolutionary lineages are included in the taxon. Sampling included 63 individuals of N. leporinus from 35 distinct localities and 43 individuals of N. albiventris from 19 localities. The mitochondrial gene cytocrome b and the control region from mtDNA were used as molecular markers. The results corroborate the paraphyly described for N. albiventris, and reveals more significant levels of phylogenetic divergence than previously observed. Three highly supported phylogroups were found within N. albiventris, all of them presenting similar phylogenetic distances to the lineage of N. leporinus. These phylogroups showed geographic structure congruent with the N. albiventris subspecies. The tests against neutrality hypothesis in N. leporinus were significant, suggesting a rapid population growth after the origin of the species. Estimates of the MRCA of the evolutionary lineages dates to the Pleistocene, for both the origin of N. leporinus and all three clades found for N. albiventris. Observed divergence between lineages varied from 4.3 to 6.1%. This study corroborates the recent origin of N. leporinus and its closest phylogenetic relationship with a N. albiventris lineage. The hypothesis for the piscivory in the genus Noctilio was the colonization of the Lesser Antilles by a population of N. albiventris during glacial cycles in the Pleistocene. This population may have differentiated, giving rise to N. leporinus, and then getting through a rapid expansion due to a trophic niche previously unexplored by any neotropical bat lineage.

Orientador: Alexandre Secorun Borges / Resumo: A miotonia hereditária (MH) é uma enfermidade muscular hereditária não distrófica. Manifesta-se pela presença de hipertrofia muscular e miotonia que melhora com o exercício, fenômeno conhecido como “warm-up”. As alterações clínicas estão associadas a mutações no gene CLCN1, codificador do canal seletivo para o íon cloreto da musculatura esquelética. A enfermidade já foi descrita em diversas espécies e algumas raças caninas; no entanto, esta é primeira descrição de MH em cães da raça American Bulldog. Quarenta e quatro cães da raça American Bulldog foram empregados na pesquisa, constituindo três grupos de estudo. O primeiro grupo, compreendeu um cão, da raça American Bulldog, com cinco meses de idade, que foi avaliado sob aspectos clínicos, eletromiográficos e moleculares. Os sinais de hipertrofia muscular, miotonia e fenômeno “warm-up” foram evidentes. Durante o exame de eletromiografia (EMG) foram verificadas a presença de descargas miotônicas. Foi verificada uma mutação “frameshift”, NM_001003124.2: c.436_437insCTCT, no gene CLCN1. A presença do transcrito alternativo NC_006598.3 (NM_001003124.2): c.774_775ins [6442_6520] foi observada no RNAm do cão miotônico. O segundo grupo constituiu-se de dez cães geneticamente relacionados com o cão do primeiro grupo. Por fim, o terceiro grupo compreendeu 33 cães não relacionados entre si e com os cães de outros grupos. Heterozigotos, cães wildtype e outro cão afetado para a mutação NM_001003124.2: c.436_437insCTCT foram observados de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hereditary Myotonia (HM) is an inherited non-dystrophic muscle disease. It is manifested by the muscular hypertrophy and myotonia that improves with exercise, a phenomenon known as "warm-up". Clinical features are associated with mutations in the CLCN1 gene, that encodes the selective channel for the skeletal muscle chloride ion. The HM has been described in several species and some dog breeds; however, this is the first report of HM in American Bulldog. The objective of this research was to describe clinical abnormalities, electromyographic and molecular characterization of hereditary myotonia in dog of this breed. 44 American Bulldog were used in the research, constituting 3 study groups. The first group included an American Bulldog, 5 months old, was evaluated under clinical, electromyographic and molecular aspects. Signs of muscle hypertrophy, myotonia, and warm-up were present. During the electromyography exam (EMG) myotonic discharges were observed. A frameshift mutation, NM_001003124.2: c.436_437insCTCT, was verified in the CLCN1 gene. The presence of an alternative transcript NC_006598.3 (NM_001003124.2): c.774_775ins [6442_6520] was observed in the myotonic dog mRNA. The second group consisted of ten dogs genetically related to the dog of the first group. Finally, the third group included 33 unrelated dogs and dogs from other groups. Heterozygotes, wildtype dogs and another dog affected by mutation NM_001003124.2: c.436_437insCTCT were observed among the ten genetica... (Complete abstract click electronic access below) / Mestre

Durch die höhere Verfügbarkeit von Schnittbildverfahren in der Kleintiermedizin treten Flüssigkeitsansammlungen in der Bulla tympanica immer häufiger als Zufallsbefund bei Hunden, insbesondere bei brachyzephalen Rassen, auf. Aufgrund der fehlenden klinischen Symptome der Patienten ist eine akute Entzündung unwahrscheinlich. Daher bezeichnen neuere Studien diese Flüssigkeitsansammlung als primär sekretorische Otitis media (PSOM). In der vorliegenden Studie wurde untersucht, ob Hunde der Rassen Mops und Französische Bulldogge mit einer primär sekretorischen Otitis media einen konduktiven Hörverlust für das betroffene Ohr im Vergleich zu „Ohr gesunden“ Hunden ihrer Rasse zeigen. Des Weiteren wurde untersucht, ob Französische Bulldoggen signifikant häufiger eine primär sekretorische Otitis media als Hunde der Rasse Mops zeigen. Es wurden bei jeweils 41 Hunde der Rasse Mops und Französische Bulldogge, die zur chirurgischen Versorgung des Brachyzephalen Syndroms vorgestellt wurden, die frühen akustisch evozierten Potentiale (FAEP) abgeleitet. Des Weiteren erfolgte bei allen Patienten eine Computertomographie des Kopfes, eine Otoskopie und ggf. eine Punktion der Bulla tympanica inklusive einer Zytologie und bakteriologischen Untersuchung des Sekrets. In der vorliegenden Studie konnte kein konduktiver Hörverlust für die Hunde mit einer PSOM nachgewiesen werden. Es zeigte sich nur eine Verlängerung der Latenz der Welle I bei Vorliegen einer PSOM, jedoch ohne dass eine signifikant erhöhte Hörschwelle für diese Patienten festgestellt werden konnte. Als Ursache für die Verlängerung der Latenz der Welle I kommt sowohl die beschriebene Füllung der Bulla als auch ein stenotischer Gehörgang in Frage. Die Hörschwelle ist zwar bei den Hunden mit einer PSOM tendenziell höher als bei den Patienten ohne Füllung der Bullae, allerdings konnte hierfür kein signifikanter Unterschied nachgewiesen werden. Bei 40 % der untersuchten Patienten mit einseitiger PSOM konnte für beide Ohren dieselbe Hörschwelle bestimmt werden, so dass eine Füllung der Bulla tympanica nicht immer zu einer vorhersagbaren Veränderung der Hörschwelle führen muss. Eine mögliche Erklärung für diesen Umstand ist ein sensorineuraler Hörverlust, der durch eine chronische Entzündung des Mittelohres zustande kommt. Dies ist bisher nur in der Humanmedizin beschrieben und die Pathogenese ist noch unklar. Die Ergebnisse zeigen zusätzlich, dass Französische Bulldoggen signifikant häufiger von einer PSOM betroffen sind. Die Ursache für diese Häufung könnte ein dickerer weicher Gaumen der Französischen Bulldoggen im Vergleich zu Hunden der Rasse Mops sein, durch den es zu einer Funktionsstörung der Tuba auditiva kommen könnte. Beim Vergleich der Hunde ohne Vorliegen einer Füllung konnte festgestellt werden, dass Französische Bulldoggen eine höhere Hörschwelle und eine längere Latenz der Welle I als Hunde der Rasse Mops aufweisen. Bei beiden Rassen ist zusätzlich auffällig, dass die Hörschwelle um 30 dB höher liegt als bei Hunden anderer Rassen (SHIU et al. 1997). Alle brachyzephalen Hunde dieser Studie zeigen somit ein im Vergleich zu anderen Rassen vermindertes Hörvermögen, das aber durch eine PSOM nicht weiter verschlechtert wird. Der Symptomenkomplex Brachyzephalen Syndrom muss nach der vorliegenden Studie durch die Symptome vermindertes Hörvermögen und das Vorliegen einer PSOM ergänzt werden. Die klinischen Auswirkungen des Hörverlusts, wie etwa eine starke Anhänglichkeit, könnten bei Hunden dieser Rassen übersehen werden, da dies als gewünschter Charakterzug der Rassen interpretiert wird und nicht als mögliches Symptom einer Erkrankung wahrgenommen wird. / Because of the increased availability of cross-sectional imaging modalities in small animal medicine the incidental finding of material in the middle ear is more common, especially in brachycephalic dogs. Because the animals show no clinical signs, an acute inflammation is unlikely. Therefore recent studies term it as primary secretory otitis media (PSOM). The aim of the current study was to determine whether brachycephalic dogs with PSOM show a conductive hearing loss compared to brachycephalic dogs without changes in the middle ear. Additionally it was evaluated whether French bulldogs suffer from PSOM more frequent than pugs. BAER was recorded in 41 pugs and 41 French bulldogs, which were under general anesthesia because of the surgical correction of the brachycephalic syndrome. In all patients a computed tomography of the head, an otoscopy and if possible a myringotomy with aspiration of the fluid in the middle ear was performed. If fluid was available a cytological examination and a bacterial culture of the fluid was initiated. In the current study no conductive hearing loss was detected in brachycephalic dogs with PSOM. The latencies of wave I were increased in patients with PSOM, although the thresholds of hearing were not increased. The increased latencies of wave I can be explained by the fluid in the middle ear as well as the stenotic external ear canal. The thresholds of hearing in dogs with PSOM were tendentially higher than in dogs without fluid in the middle ear, but the correlation was not significant. In 40 % of the patients with PSOM in one ear the threshold of hearing in both ears is at the same level. Therefore there is no strict correlation between fluid in the middle ear and an increased threshold of hearing on the affected side. This could be explained by a sensorineural hearing loss caused by chronic inflammation of the middle ear. Until now a chronic inflammation as a cause of sensorineural hearing loss has only been described in human medicine, not in veterinary medicine. The pathogenesis is still unknown. The results show that French bulldogs suffer more frequently from the PSOM than pugs. French bulldogs usually show a bigger soft palate than pugs which could result in a dysfunction of the tuba auditiva. Hence the bigger soft palate could be causing the increased prevalence of PSOM in French bulldogs. Compared to pugs without PSOM, French bulldogs without PSOM show an increased latency of wave I as well as an increased threshold of hearing. Additionally for both breeds an increase in the threshold of hearing by 30 dB compared to normocephalic breeds could be detected (SHIU et al. 1997). It is remarkable that French bulldogs as well as pugs show a hearing loss without correlation to the PSOM. In conclusion hearing loss has to be added to the characteristic triad of symptoms of the brachycephalic syndrome. Clinical signs of hearing loss like loyalty to the owner could be misinterpreted especially in these breeds, since this is a favored behavior of these dogs.

Mémoire en neurologie vétérinaire

No description available.

Durch die höhere Verfügbarkeit von Schnittbildverfahren in der Kleintiermedizin treten Flüssigkeitsansammlungen in der Bulla tympanica immer häufiger als Zufallsbefund bei Hunden, insbesondere bei brachyzephalen Rassen, auf. Aufgrund der fehlenden klinischen Symptome der Patienten ist eine akute Entzündung unwahrscheinlich. Daher bezeichnen neuere Studien diese Flüssigkeitsansammlung als primär sekretorische Otitis media (PSOM). In der vorliegenden Studie wurde untersucht, ob Hunde der Rassen Mops und Französische Bulldogge mit einer primär sekretorischen Otitis media einen konduktiven Hörverlust für das betroffene Ohr im Vergleich zu „Ohr gesunden“ Hunden ihrer Rasse zeigen. Des Weiteren wurde untersucht, ob Französische Bulldoggen signifikant häufiger eine primär sekretorische Otitis media als Hunde der Rasse Mops zeigen. Es wurden bei jeweils 41 Hunde der Rasse Mops und Französische Bulldogge, die zur chirurgischen Versorgung des Brachyzephalen Syndroms vorgestellt wurden, die frühen akustisch evozierten Potentiale (FAEP) abgeleitet. Des Weiteren erfolgte bei allen Patienten eine Computertomographie des Kopfes, eine Otoskopie und ggf. eine Punktion der Bulla tympanica inklusive einer Zytologie und bakteriologischen Untersuchung des Sekrets. In der vorliegenden Studie konnte kein konduktiver Hörverlust für die Hunde mit einer PSOM nachgewiesen werden. Es zeigte sich nur eine Verlängerung der Latenz der Welle I bei Vorliegen einer PSOM, jedoch ohne dass eine signifikant erhöhte Hörschwelle für diese Patienten festgestellt werden konnte. Als Ursache für die Verlängerung der Latenz der Welle I kommt sowohl die beschriebene Füllung der Bulla als auch ein stenotischer Gehörgang in Frage. Die Hörschwelle ist zwar bei den Hunden mit einer PSOM tendenziell höher als bei den Patienten ohne Füllung der Bullae, allerdings konnte hierfür kein signifikanter Unterschied nachgewiesen werden. Bei 40 % der untersuchten Patienten mit einseitiger PSOM konnte für beide Ohren dieselbe Hörschwelle bestimmt werden, so dass eine Füllung der Bulla tympanica nicht immer zu einer vorhersagbaren Veränderung der Hörschwelle führen muss. Eine mögliche Erklärung für diesen Umstand ist ein sensorineuraler Hörverlust, der durch eine chronische Entzündung des Mittelohres zustande kommt. Dies ist bisher nur in der Humanmedizin beschrieben und die Pathogenese ist noch unklar. Die Ergebnisse zeigen zusätzlich, dass Französische Bulldoggen signifikant häufiger von einer PSOM betroffen sind. Die Ursache für diese Häufung könnte ein dickerer weicher Gaumen der Französischen Bulldoggen im Vergleich zu Hunden der Rasse Mops sein, durch den es zu einer Funktionsstörung der Tuba auditiva kommen könnte. Beim Vergleich der Hunde ohne Vorliegen einer Füllung konnte festgestellt werden, dass Französische Bulldoggen eine höhere Hörschwelle und eine längere Latenz der Welle I als Hunde der Rasse Mops aufweisen. Bei beiden Rassen ist zusätzlich auffällig, dass die Hörschwelle um 30 dB höher liegt als bei Hunden anderer Rassen (SHIU et al. 1997). Alle brachyzephalen Hunde dieser Studie zeigen somit ein im Vergleich zu anderen Rassen vermindertes Hörvermögen, das aber durch eine PSOM nicht weiter verschlechtert wird. Der Symptomenkomplex Brachyzephalen Syndrom muss nach der vorliegenden Studie durch die Symptome vermindertes Hörvermögen und das Vorliegen einer PSOM ergänzt werden. Die klinischen Auswirkungen des Hörverlusts, wie etwa eine starke Anhänglichkeit, könnten bei Hunden dieser Rassen übersehen werden, da dies als gewünschter Charakterzug der Rassen interpretiert wird und nicht als mögliches Symptom einer Erkrankung wahrgenommen wird. / Because of the increased availability of cross-sectional imaging modalities in small animal medicine the incidental finding of material in the middle ear is more common, especially in brachycephalic dogs. Because the animals show no clinical signs, an acute inflammation is unlikely. Therefore recent studies term it as primary secretory otitis media (PSOM). The aim of the current study was to determine whether brachycephalic dogs with PSOM show a conductive hearing loss compared to brachycephalic dogs without changes in the middle ear. Additionally it was evaluated whether French bulldogs suffer from PSOM more frequent than pugs. BAER was recorded in 41 pugs and 41 French bulldogs, which were under general anesthesia because of the surgical correction of the brachycephalic syndrome. In all patients a computed tomography of the head, an otoscopy and if possible a myringotomy with aspiration of the fluid in the middle ear was performed. If fluid was available a cytological examination and a bacterial culture of the fluid was initiated. In the current study no conductive hearing loss was detected in brachycephalic dogs with PSOM. The latencies of wave I were increased in patients with PSOM, although the thresholds of hearing were not increased. The increased latencies of wave I can be explained by the fluid in the middle ear as well as the stenotic external ear canal. The thresholds of hearing in dogs with PSOM were tendentially higher than in dogs without fluid in the middle ear, but the correlation was not significant. In 40 % of the patients with PSOM in one ear the threshold of hearing in both ears is at the same level. Therefore there is no strict correlation between fluid in the middle ear and an increased threshold of hearing on the affected side. This could be explained by a sensorineural hearing loss caused by chronic inflammation of the middle ear. Until now a chronic inflammation as a cause of sensorineural hearing loss has only been described in human medicine, not in veterinary medicine. The pathogenesis is still unknown. The results show that French bulldogs suffer more frequently from the PSOM than pugs. French bulldogs usually show a bigger soft palate than pugs which could result in a dysfunction of the tuba auditiva. Hence the bigger soft palate could be causing the increased prevalence of PSOM in French bulldogs. Compared to pugs without PSOM, French bulldogs without PSOM show an increased latency of wave I as well as an increased threshold of hearing. Additionally for both breeds an increase in the threshold of hearing by 30 dB compared to normocephalic breeds could be detected (SHIU et al. 1997). It is remarkable that French bulldogs as well as pugs show a hearing loss without correlation to the PSOM. In conclusion hearing loss has to be added to the characteristic triad of symptoms of the brachycephalic syndrome. Clinical signs of hearing loss like loyalty to the owner could be misinterpreted especially in these breeds, since this is a favored behavior of these dogs.