Timoma canino associado à miastenia gravis / Canine thymoma associated to myasthenia gravis

Background: Thymomas are epithelial neoplasms of the thymus, although lymphocyte infiltration is common. Histological features are not sufficient to define its biological behaviour, which is dependent of clinical criteria of invasiveness and resectability. Myasthenia gravis may happen as a paraneoplastic syndrome in up to 47% of canine thymomas. This article aims at reporting a case of thymoma associated with myasthenia gravis in a dog, emphasizing the morphological, phenotypical and therapeutical aspects.Case: A 7-year-old, male Labrador, was presented with a history of acute dyspnea and exercise intolerance. The physical examination revealed a “red-brick” mucousa, tachycardia and cardiac and pulmonar hypofonese. Chest radiographs revealed an area of increased radiopacity in the cranial mediastinum without a plane of separation to the heart. The eccodopplercardiogram exam identified a poorly delimited mass adjacent to the base of the heart, measuring 9.5x6.8cm. Computed tomography demonstrated it as an expansive neoformation (9.5x6.5x7.8cm). Mass was removed through intercostal thoracotomy and the removed tissue was submitted to histopathology with a diagnosis compatible with type AB thymoma (mixed). Immunohistochemistry was positive for AE1/AE3 citokeratin in 90% of epithelial cells, confirming tumour origin. Tumour infiltrating lymphocytes were positive for CD79a (70%) and CD3 (20%). The proliferation index (Ki-67 imunolabeling) was 60%. About 45 days after surgery the patient was presented with generalized muscle weakness and regurgitation, with confirmed megaesophagus on chest X-ray. Treatment with pyridostigmine was initiated because of suspected myasthenia gravis, and complete remission of the neurological signs occurred within a month. A chemotherapeutic protocol with carboplatin was then instituted. After four sessions, a new thoracic radiograph revealed tumour recurrence in the cranial mediastinum.[...]

Timoma canino associado à miastenia gravis / Canine thymoma associated to myasthenia gravis

Background: Thymomas are epithelial neoplasms of the thymus, although lymphocyte infiltration is common. Histological features are not sufficient to define its biological behaviour, which is dependent of clinical criteria of invasiveness and resectability. Myasthenia gravis may happen as a paraneoplastic syndrome in up to 47% of canine thymomas. This article aims at reporting a case of thymoma associated with myasthenia gravis in a dog, emphasizing the morphological, phenotypical and therapeutical aspects.Case: A 7-year-old, male Labrador, was presented with a history of acute dyspnea and exercise intolerance. The physical examination revealed a “red-brick” mucousa, tachycardia and cardiac and pulmonar hypofonese. Chest radiographs revealed an area of increased radiopacity in the cranial mediastinum without a plane of separation to the heart. The eccodopplercardiogram exam identified a poorly delimited mass adjacent to the base of the heart, measuring 9.5x6.8cm. Computed tomography demonstrated it as an expansive neoformation (9.5x6.5x7.8cm). Mass was removed through intercostal thoracotomy and the removed tissue was submitted to histopathology with a diagnosis compatible with type AB thymoma (mixed). Immunohistochemistry was positive for AE1/AE3 citokeratin in 90% of epithelial cells, confirming tumour origin. Tumour infiltrating lymphocytes were positive for CD79a (70%) and CD3 (20%). The proliferation index (Ki-67 imunolabeling) was 60%. About 45 days after surgery the patient was presented with generalized muscle weakness and regurgitation, with confirmed megaesophagus on chest X-ray. Treatment with pyridostigmine was initiated because of suspected myasthenia gravis, and complete remission of the neurological signs occurred within a month. A chemotherapeutic protocol with carboplatin was then instituted. After four sessions, a new thoracic radiograph revealed tumour recurrence in the cranial mediastinum.[...](AU)

Megaesôfago secondary to miastenia gravis: case report on a dog / Megaesôfago secundário à miastenia gravis: relato de caso em um cão

The megaesophagus a dilatation of the whole or some portions of esophagus, an unusual cat disease can be seen more frequently in dogs is classified as congenital or acquired. The acquired form usually presents in adult dogs from eight years of age, secondary to other disorders, mainly to diseases that cause neuromuscular changes like myasthenia gravis, hypoadrenocorticism and dysautonomia in cats. This report describes a case of megaesophagus secondary to myasthenia gravis in a male, nondefined canine with nine years of age, analyze the diagnosis and treatment methods of applied, bu in the present case, the diagnosis was concluded by thoracic radiography, in addition to the established therapy associated with patient management, which ensured the animal significant clinical improvement and life quality.

O megaesôfago, uma dilatação total ou de partes específicas do esôfago enfermidade incomum em gatos, porém vista com maior frequência em cães é classificada como congênita ou adquirida. A forma adquirida geralmente é observada em cães adultos a partir de oito anos de idade, secundariamente a outros distúrbios, principalmente a doenças que provocam alterações neuromusculares, como miastenia gravis, hipoadrenocorticismo e disautonomia nos gatos. Este relato descreve um caso de megaesôfago secundário à miastenia gravis em um canino, macho, sem raça definida e com nove anos de idade, além de discutir os métodos de diagnóstico e tratamentos dessa enfermidade. Nesse caso, o diagnóstico pôde ser concluído com o emprego da radiografia torácica, além da terapia instituída associada ao manejo do paciente, o que garantiu ao animal melhora clínica significativa e qualidade de vida.

Megaesôfago secondary to miastenia gravis: case report on a dog / Megaesôfago secundário à miastenia gravis: relato de caso em um cão

The megaesophagus a dilatation of the whole or some portions of esophagus, an unusual cat disease can be seen more frequently in dogs is classified as congenital or acquired. The acquired form usually presents in adult dogs from eight years of age, secondary to other disorders, mainly to diseases that cause neuromuscular changes like myasthenia gravis, hypoadrenocorticism and dysautonomia in cats. This report describes a case of megaesophagus secondary to myasthenia gravis in a male, nondefined canine with nine years of age, analyze the diagnosis and treatment methods of applied, bu in the present case, the diagnosis was concluded by thoracic radiography, in addition to the established therapy associated with patient management, which ensured the animal significant clinical improvement and life quality.(AU)

O megaesôfago, uma dilatação total ou de partes específicas do esôfago enfermidade incomum em gatos, porém vista com maior frequência em cães é classificada como congênita ou adquirida. A forma adquirida geralmente é observada em cães adultos a partir de oito anos de idade, secundariamente a outros distúrbios, principalmente a doenças que provocam alterações neuromusculares, como miastenia gravis, hipoadrenocorticismo e disautonomia nos gatos. Este relato descreve um caso de megaesôfago secundário à miastenia gravis em um canino, macho, sem raça definida e com nove anos de idade, além de discutir os métodos de diagnóstico e tratamentos dessa enfermidade. Nesse caso, o diagnóstico pôde ser concluído com o emprego da radiografia torácica, além da terapia instituída associada ao manejo do paciente, o que garantiu ao animal melhora clínica significativa e qualidade de vida.(AU)

Megaesófago secundario a la miastenia gravis / Megaesophagus secondary to myasthenia gravis / gravis

Astenia esofágica o megaesófago se define por una dilatación patológica del esófago y caracterizado por una insuficiencia progresiva de las olas peristálticas. Esta enfermedad se puede clasificar en: idiopática, congénita o adquirida secundaria. La causa más común del megaesófago secundario es Miastenia gravis. Esta enfermedad se caracteriza por ser una neuropatía que desencadena un trastorno neuromuscular que causa debilidad del músculo esquelético, el esófago, la faringe y la laringe. La debilidad muscular se correlaciona con la mejoría tras el descanso y empeora con el ejercicio. El megaesófago secundario adquirido a la miastenia gravis se caracteriza por la interrupción del reflejo nervioso, controlador de la deglutición que afecta el funcionamiento de los músculos del esófago, lo que lleva a la dilatación pasiva del órgano. Razas como Pastor Alemán, Golden Retriever y Setter Irlandés tienen una mayor predisposición a la enfermedad.(AU)

Esophageal asthenia or megaesophagus is defined as a pathological dilation and progressive failure of peristaltic waves. This disease can be classified in: idiopathic, congenity or acquired secondary. The most common cause of acquired secondary megaesophagus is myasthenia gravis. This disease is defined as a neuropathy that develops a neuromuscular disorder, resulting in muscle weakness, of the esophagus, of the larynx and of the pharynx. The muscle weakness is related to improvement after rest and worsening with exercise. The megaesophagus secondary to myasthenia gravis is defined to nervous reflex breakdown, swallowing controller or lesions that affect the esophageal muscle function, resulting in an organ passive dilation. Breeds like German Shepherd, Golden Retriever and Irish Setter have a greater predisposition to disease.(AU)

Astenia esofágica ou megaesôfago é definido por uma dilatação patológica do esôfago e caracterizado por uma falha progressiva das ondas peristálticas. Essa doença pode ser classificada em: idiopática, congênita ou secundária adquirida. A causa mais comum de megaesôfago secundário adquirido é a miastenia gravis. Tal doença é caracterizada por ser uma neuropatia que desencadeia uma desordem neuromuscular, provocando fraqueza de musculatura esquelética, esôfago, faringe e laringe. A fraqueza muscular está correlacionada com melhora após o descanso e piora com o exercício. O megaesôfago adquirido secundário a miastenia gravis é caracterizado pelo rompimento do reflexo nervoso, controlador da deglutição ou que afeta o funcionamento da musculatura esofágica, levando a dilatação passiva do órgão. Raças como Pastor Alemão, Golden Retriever e Setter Irlandês possuem maior predisposição à doença.(AU)

Megaesófago secundario a la miastenia gravis / Megaesophagus secondary to myasthenia gravis / gravis

Astenia esofágica o megaesófago se define por una dilatación patológica del esófago y caracterizado por una insuficiencia progresiva de las olas peristálticas. Esta enfermedad se puede clasificar en: idiopática, congénita o adquirida secundaria. La causa más común del megaesófago secundario es Miastenia gravis. Esta enfermedad se caracteriza por ser una neuropatía que desencadena un trastorno neuromuscular que causa debilidad del músculo esquelético, el esófago, la faringe y la laringe. La debilidad muscular se correlaciona con la mejoría tras el descanso y empeora con el ejercicio. El megaesófago secundario adquirido a la miastenia gravis se caracteriza por la interrupción del reflejo nervioso, controlador de la deglutición que afecta el funcionamiento de los músculos del esófago, lo que lleva a la dilatación pasiva del órgano. Razas como Pastor Alemán, Golden Retriever y Setter Irlandés tienen una mayor predisposición a la enfermedad.

Esophageal asthenia or megaesophagus is defined as a pathological dilation and progressive failure of peristaltic waves. This disease can be classified in: idiopathic, congenity or acquired secondary. The most common cause of acquired secondary megaesophagus is myasthenia gravis. This disease is defined as a neuropathy that develops a neuromuscular disorder, resulting in muscle weakness, of the esophagus, of the larynx and of the pharynx. The muscle weakness is related to improvement after rest and worsening with exercise. The megaesophagus secondary to myasthenia gravis is defined to nervous reflex breakdown, swallowing controller or lesions that affect the esophageal muscle function, resulting in an organ passive dilation. Breeds like German Shepherd, Golden Retriever and Irish Setter have a greater predisposition to disease.

Astenia esofágica ou megaesôfago é definido por uma dilatação patológica do esôfago e caracterizado por uma falha progressiva das ondas peristálticas. Essa doença pode ser classificada em: idiopática, congênita ou secundária adquirida. A causa mais comum de megaesôfago secundário adquirido é a miastenia gravis. Tal doença é caracterizada por ser uma neuropatia que desencadeia uma desordem neuromuscular, provocando fraqueza de musculatura esquelética, esôfago, faringe e laringe. A fraqueza muscular está correlacionada com melhora após o descanso e piora com o exercício. O megaesôfago adquirido secundário a miastenia gravis é caracterizado pelo rompimento do reflexo nervoso, controlador da deglutição ou que afeta o funcionamento da musculatura esofágica, levando a dilatação passiva do órgão. Raças como Pastor Alemão, Golden Retriever e Setter Irlandês possuem maior predisposição à doença.

Myasthenia gravis in an exotic shorthair cat

Background: Myasthenia gravis is a neuromuscular transmission disorder resulting from the deficiency or functional disturbance of the acetylcholine receptors at the neuromuscular junction with consequent impairment of action potential transmission from nerve to muscle and it can be either congenital or acquired. Acquired myasthenia gravis has been described less frenquently in cats. The purpose of this paper is to describe a case of acquired myasthenia gravis in a 6-month-old male Exotic Shorthair cat. Case: A 6-month-old male Exotic Shorthair cat was referred to the Veterinary Clinic with a 2-day history of flaccid paralysis of the four limbs. The cat was feeding well and defecating normally. Physical examination was unremarkable. On neurological examination the patient was bright, alert and responsive. Flaccid paralysis of the four limbs was evident with loss of muscular tonus and presence of superficial and deep nociception. All spinal reflexes were absent. Hematologic analysis was within normal parameters. Thoracic radiographs were taken and showed no abnormalities. Creatine kinase activity was elevated. Myasthenia gravis was suspected and the cat was submitted to an neostigmine methylsulfate injection and further pyridostigmine bromide administration. Within 15 days there was clinical improvement with muscular tonus and spinal reflexes recovery. The treatment was continued...(AU)

Myasthenia gravis in an exotic shorthair cat

Background: Myasthenia gravis is a neuromuscular transmission disorder resulting from the deficiency or functional disturbance of the acetylcholine receptors at the neuromuscular junction with consequent impairment of action potential transmission from nerve to muscle and it can be either congenital or acquired. Acquired myasthenia gravis has been described less frenquently in cats. The purpose of this paper is to describe a case of acquired myasthenia gravis in a 6-month-old male Exotic Shorthair cat. Case: A 6-month-old male Exotic Shorthair cat was referred to the Veterinary Clinic with a 2-day history of flaccid paralysis of the four limbs. The cat was feeding well and defecating normally. Physical examination was unremarkable. On neurological examination the patient was bright, alert and responsive. Flaccid paralysis of the four limbs was evident with loss of muscular tonus and presence of superficial and deep nociception. All spinal reflexes were absent. Hematologic analysis was within normal parameters. Thoracic radiographs were taken and showed no abnormalities. Creatine kinase activity was elevated. Myasthenia gravis was suspected and the cat was submitted to an neostigmine methylsulfate injection and further pyridostigmine bromide administration. Within 15 days there was clinical improvement with muscular tonus and spinal reflexes recovery. The treatment was continued...

Miastenia gravis generalizada adquirida em cão relato de caso / Acquired generalized myastenia gravis in a doga case report

A Miastenia gravis adquirida pode desenvolver-se em qualquer raça canina e é considerado umdos principais distúrbios imunomediados que afetam o sistema neuromuscular dos cães, caracterizadaprincipalmente por fraqueza muscular e fadiga, que pioram com o exercício físico. Oprognóstico é reservado, principalmente quando associado à megaesôfago, devido ao risco depneumonia por aspiração que pode levar ao óbito. O diagnóstico torna-se muitas vezes desafiantedevido à similaridade com outras alterações neuromusculares. O diagnóstico definitivo é feitopela identificação de anticorpos antirreceptores de acetilcolina presentes no soro sanguíneo, maspode ser terapêutico, confirmado pela remissão dos sinais clínicos após tratamento com fármacosanticolinesterásicos. Este trabalho tem como objetivo relatar o caso de um cão com Miasteniagravis generalizada adquirida, ressaltando a importância do diagnóstico terapêutico feito combrometo de piridostigmina, bem como o acompanhamento de seus aspectos clínicos até completaremissão da doença.(AU)

The acquired myasthenia gravis can develop in any breed of dog and is considered one of the mostcommon immune-mediated disorders that affect the neuromuscular system of dogs, mainly characterizedby muscle weakness and fatigue that worsens during exercise. The prognosis is guarded,especially when associated with megaesophagus, due to risk of aspiration pneumonia that can leadto death. The diagnosis often becomes challenging due to the similarity to other neuromusculardisorders. The definitive diagnosis is done through the identification of antibodies against acetylcholinereceptors present in blood serum, but may be accomplished by remission of clinical signsafter administration of an anticholinesterase drug. This paper aims to reporting a case of a dogwith acquired generalized myasthenia gravis emphasizing the importance of therapeutic diagnosingmade by use of pyridostigmine bromide, and the monitoring of its clinical features until completeremission of the disease.(AU).

Miastenia gravis generalizada adquirida em cão – relato de caso / Acquired generalized myastenia gravis in a dog– a case report

A Miastenia gravis adquirida pode desenvolver-se em qualquer raça canina e é considerado umdos principais distúrbios imunomediados que afetam o sistema neuromuscular dos cães, caracterizadaprincipalmente por fraqueza muscular e fadiga, que pioram com o exercício físico. Oprognóstico é reservado, principalmente quando associado à megaesôfago, devido ao risco depneumonia por aspiração que pode levar ao óbito. O diagnóstico torna-se muitas vezes desafiantedevido à similaridade com outras alterações neuromusculares. O diagnóstico definitivo é feitopela identificação de anticorpos antirreceptores de acetilcolina presentes no soro sanguíneo, maspode ser terapêutico, confirmado pela remissão dos sinais clínicos após tratamento com fármacosanticolinesterásicos. Este trabalho tem como objetivo relatar o caso de um cão com Miasteniagravis generalizada adquirida, ressaltando a importância do diagnóstico terapêutico feito combrometo de piridostigmina, bem como o acompanhamento de seus aspectos clínicos até completaremissão da doença.

The acquired myasthenia gravis can develop in any breed of dog and is considered one of the mostcommon immune-mediated disorders that affect the neuromuscular system of dogs, mainly characterizedby muscle weakness and fatigue that worsens during exercise. The prognosis is guarded,especially when associated with megaesophagus, due to risk of aspiration pneumonia that can leadto death. The diagnosis often becomes challenging due to the similarity to other neuromusculardisorders. The definitive diagnosis is done through the identification of antibodies against acetylcholinereceptors present in blood serum, but may be accomplished by remission of clinical signsafter administration of an anticholinesterase drug. This paper aims to reporting a case of a dogwith acquired generalized myasthenia gravis emphasizing the importance of therapeutic diagnosingmade by use of pyridostigmine bromide, and the monitoring of its clinical features until completeremission of the disease..

Síndrome Wei em pequenos animais / Wei Syndrome in small animals

A preocupação cada vez mais crescente dos proprietários com seus animais de companhia vêm fazendo com que busquem novas alternativas para que se complemente o tratamento ou controle das doenças crônicas, debilitantes e/ou degenerativas em seus animais. Dessa forma, a acupuntura tem contribuído para a diminuição e até muitas vezes para a remissão do conjunto de sinais clínicos que levam à disfunção e atrofia dos músculos, conhecida como Síndrome Wei na Medicina Tradicional Chinesa, e que na Medicina Ocidental é observada em diversas doenças, dentre elas botulismo, miastenia gravis, polirradiculoneurite e cinomose (seqüelas). Este trabalho tem por objetivo descrever a Síndrome Wei, bem como as duas principais formas de tratamento – acupuntura e fitoterapia chinesa – usadas na Medicina Chinesa

The growing concern of the owners with their pest resulting in the searching of new alternatives to complement the treatment and the controlol of the weakeningly and/or degenerative chronic pathologies in pets. Thus, the acupuncture has been contributing to decrease and even for elimination of the group of clinical symptoms resulting in dysfunction and atrophies of the muscles – known as Wei Syndrome in the Chinese Traditional Medicine. In the Western Medicine it is observed in a wide group of pathologies, among them the botulism, miastenia gravis, polyradiculoneuritis and dog distemper (sequels). This work has the objective of describing the Wei Syndrome, as well as the two main treatment types – acupuncture and Chinese phytotheraphy – both used in the Chinese Medicine

Síndrome Wei em pequenos animais / Wei Syndrome in small animals

A preocupação cada vez mais crescente dos proprietários com seus animais de companhia vêm fazendo com que busquem novas alternativas para que se complemente o tratamento ou controle das doenças crônicas, debilitantes e/ou degenerativas em seus animais. Dessa forma, a acupuntura tem contribuído para a diminuição e até muitas vezes para a remissão do conjunto de sinais clínicos que levam à disfunção e atrofia dos músculos, conhecida como Síndrome Wei na Medicina Tradicional Chinesa, e que na Medicina Ocidental é observada em diversas doenças, dentre elas botulismo, miastenia gravis, polirradiculoneurite e cinomose (seqüelas). Este trabalho tem por objetivo descrever a Síndrome Wei, bem como as duas principais formas de tratamento acupuntura e fitoterapia chinesa usadas na Medicina Chinesa(AU)

The growing concern of the owners with their pest resulting in the searching of new alternatives to complement the treatment and the controlol of the weakeningly and/or degenerative chronic pathologies in pets. Thus, the acupuncture has been contributing to decrease and even for elimination of the group of clinical symptoms resulting in dysfunction and atrophies of the muscles known as Wei Syndrome in the Chinese Traditional Medicine. In the Western Medicine it is observed in a wide group of pathologies, among them the botulism, miastenia gravis, polyradiculoneuritis and dog distemper (sequels). This work has the objective of describing the Wei Syndrome, as well as the two main treatment types acupuncture and Chinese phytotheraphy both used in the Chinese Medicine(AU)

Megaesophagus secondary to myasthenia gravis in a female German shepherd dog / Megaesôfago secundário a miastenia grave em uma cadela da raça Pastor Alemão

Megaesophagus is a common cause of regurgitation being one of the possible etiologies the myasthenia gravis characterized by a neuromuscular disorder that result in weakness of the skeletal muscles, of the esophagus, of the larynx and of the pharynx. The present report describes a case of a female German shepherd dog, with report of muscles weakness and frequent vomits, which was diagnosed as a megaesophagus secondary to myasthenia gravis. The radiograph of the animal presented an accentuated cervical and thoracic megaesophagus. After the institution of the recommended therapeutic protocol the animal presented visible improvement when walking, however the regurgitations worsened and it began to present cough. New radiograph was accomplished with presence, besides megaesophagus, of aspiration pneumonia. The owner opted for the euthanasia of the animal and the necropsy revealed severe pneumonia and an accentuated dilation of the posterior portion of the esophagus, collaborating with subsidies for an unfavorable prognostic of the case.

Megaesôfago é uma causa comum de regurgitação sendo uma das possíveis etiologias a miastenia grave caracterizada por uma desordem neuromuscular que resulta em fraqueza dos músculos esqueléticos, do esôfago, da laringe e da faringe. O presente relato descreve um caso de uma cadela da raça Pastor Alemão, com histórico de fraqueza muscular e vômitos freqûentes, que foi diagnosticada como megaesôfago secundário à miastenia grave. A radiografia do animal apresentou um acentuado megaesôfago cervical e torácico. Após a instituição do protocolo terapêutico recomendado o animal apresentou melhora visível ao caminhar, porém as regurgitações pioraram e começou a apresentar tosse. Foi realizado novo exame radiográfico com presença, além de megaesôfago, de pneumonia aspirativa. A proprietária optou pela eutanásia do animal e a necropsia revelou severa pneumonia e dilatação acentuada da porção caudal do esôfago, caracterizando um megaesôfago de grande dimensão, colaborando com subsídios para um prognóstico desfavorável do caso.

Megaesophagus secondary to myasthenia gravis in a female German shepherd dog / Megaesôfago secundário a miastenia grave em uma cadela da raça Pastor Alemão

Megaesophagus is a common cause of regurgitation being one of the possible etiologies the myasthenia gravis characterized by a neuromuscular disorder that result in weakness of the skeletal muscles, of the esophagus, of the larynx and of the pharynx. The present report describes a case of a female German shepherd dog, with report of muscles weakness and frequent vomits, which was diagnosed as a megaesophagus secondary to myasthenia gravis. The radiograph of the animal presented an accentuated cervical and thoracic megaesophagus. After the institution of the recommended therapeutic protocol the animal presented visible improvement when walking, however the regurgitations worsened and it began to present cough. New radiograph was accomplished with presence, besides megaesophagus, of aspiration pneumonia. The owner opted for the euthanasia of the animal and the necropsy revealed severe pneumonia and an accentuated dilation of the posterior portion of the esophagus, collaborating with subsidies for an unfavorable prognostic of the case.

Megaesôfago é uma causa comum de regurgitação sendo uma das possíveis etiologias a miastenia grave caracterizada por uma desordem neuromuscular que resulta em fraqueza dos músculos esqueléticos, do esôfago, da laringe e da faringe. O presente relato descreve um caso de uma cadela da raça Pastor Alemão, com histórico de fraqueza muscular e vômitos freqüentes, que foi diagnosticada como megaesôfago secundário à miastenia grave. A radiografia do animal apresentou um acentuado megaesôfago cervical e torácico. Após a instituição do protocolo terapêutico recomendado o animal apresentou melhora visível ao caminhar, porém as regurgitações pioraram e começou a apresentar tosse. Foi realizado novo exame radiográfico com presença, além de megaesôfago, de pneumonia aspirativa. A proprietária optou pela eutanásia do animal e a necropsia revelou severa pneumonia e dilatação acentuada da porção caudal do esôfago, caracterizando um megaesôfago de grande dimensão, colaborando com subsídios para um prognóstico desfavorável do caso.

Megaesophagus secondary to myasthenia gravis in a female German shepherd dog / Megaesôfago secundário a miastenia grave em uma cadela da raça Pastor Alemão

Megaesophagus is a common cause of regurgitation being one of the possible etiologies the myasthenia gravis characterized by a neuromuscular disorder that result in weakness of the skeletal muscles, of the esophagus, of the larynx and of the pharynx. The present report describes a case of a female German shepherd dog, with report of muscles weakness and frequent vomits, which was diagnosed as a megaesophagus secondary to myasthenia gravis. The radiograph of the animal presented an accentuated cervical and thoracic megaesophagus. After the institution of the recommended therapeutic protocol the animal presented visible improvement when walking, however the regurgitations worsened and it began to present cough. New radiograph was accomplished with presence, besides megaesophagus, of aspiration pneumonia. The owner opted for the euthanasia of the animal and the necropsy revealed severe pneumonia and an accentuated dilation of the posterior portion of the esophagus, collaborating with subsidies for an unfavorable prognostic of the case.

Megaesôfago é uma causa comum de regurgitação sendo uma das possíveis etiologias a miastenia grave caracterizada por uma desordem neuromuscular que resulta em fraqueza dos músculos esqueléticos, do esôfago, da laringe e da faringe. O presente relato descreve um caso de uma cadela da raça Pastor Alemão, com histórico de fraqueza muscular e vômitos freqüentes, que foi diagnosticada como megaesôfago secundário à miastenia grave. A radiografia do animal apresentou um acentuado megaesôfago cervical e torácico. Após a instituição do protocolo terapêutico recomendado o animal apresentou melhora visível ao caminhar, porém as regurgitações pioraram e começou a apresentar tosse. Foi realizado novo exame radiográfico com presença, além de megaesôfago, de pneumonia aspirativa. A proprietária optou pela eutanásia do animal e a necropsia revelou severa pneumonia e dilatação acentuada da porção caudal do esôfago, caracterizando um megaesôfago de grande dimensão, colaborando com subsídios para um prognóstico desfavorável do caso.